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Afý HIGH VOLTAGE TESTING:


SPECIFICATIONS AND TEST
PROCEDURE

W.G. Dunbar

Boeing Avotpece Company


P.O. Rox 3999
Ssatte, Wa.~iington 98124

August 1982L

FkWa Report for Paod 29 Seplamber 1979 -1 JuMY 1962 $

Approved for public r~elem; distribution unlimited.

Air Force Wot AeronauticalLaboratories

Forc Sytm -Air-.


Command...
NOTICE

"When Government drawings, specifications, o.* other data are used for any purpose
other than in connection with a definitely related Government procurement operation,
the United States Govenrment thereby incurs no responsibility nor any obligation
"whatsoever;and t.he fact that the government may have formulated, furnished, or in
"any way supplied the said drawings, specifications, or ,:'herdata, is not to be re-
garded by implication or otherwise as in any manner licensing the holder or any
other person or corporation, or conveying any rights or permission to manufacture
use, or sell any patented invention that may in any way be related thereto.

This report has been reviewed by the Office of Public Affairs (ASD/PA) and is
releasable to the National Technical Information Service (NTIS). At NTIS, it ;.ill
be available to the eneral public, including foreign nations.

This technical report has been reviewed and is approved for publication.

DANIEL L. SCHWEICKART PAUL R. BERTHEAUD


PROJECT ENGINEER Technical Area Manager
Power Systems Branch
Aerospace Power Division

FOR THE COMMANDER

J.A R . REAM•S
Chief, Aerospace Power Division
Aero Propulsion Laboratory

"If your address has changed, if you wish to be removed from our mailing list, or
if the addressee is no longer employed by your organization please nz tify AUL/P0CS,
W-PAFB, OH 45433 to help us maintain a current mailing list".

Copies of this report should not be returned unless return is required by security
considerations, contractital obligations, or notice on a specific document.

V. " . ° . . • ° - . - . • . °°.° .o , • , , , ° • •° . •. , "


Unerl -ifipd
SECURITY CLASSIFICATION OF THIS PAGE ("oen Date Entered)

READ INSTRUCTIONS
REPORT DOCUMENTATION PAGE BEFORE COMPLETING FORM
I. REOR NUBE. GOVT ACCESSION NO.,-RCPETSCTLCNME

4. TITLE (and Subtitle) 5. TYPE OF REPORT & PERIOD COVERED

High Voeltage TestlngSpecifications and . Final Report, 29 Sept. 1979


Procedures I JulyRER N
NUMBER
F. ORMING ORO. REPORT
7. AUTHOR(&) . CONTRACT OR GRANT NUMBER(&)

W. G. Dunbar F33615-79-C-2067
9. PERFORMING OrtGANIZATION NAME AND ADDRESS 10 PROGRAM ELEMENT. PROJECT. TASK
AREA & WORK UNIT NUMBERS

Boeing Aerospace Company


P. O. Box 3999 3145-32-50
Seattle. Wa •hingtnn 9l124
It. CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT DATE

Aero Propulsion Laboratory AUG 82


AFWAL/P005-2
Wright-Patt•rqnn AIR AlN 4 14
1
13. NUMBER OF PAGES
....463
14. MON.IORING AGENCY NAME 8 ADDRESS(Ildlfforent from Contraollng Office) 15. SECURITY CLASS. (of this report)

Unclassified
15a. OECLASSIFICATION/DOWNGRADING
SCHEDULE

16. DISTRIBUTION STATEMENT (of this Report)

Approved for public release; distribution unlimited.

17. DISTRIBUTION STATEMENT (of the abetract entered In Block 20, It different from Ret-rt)

18. SUPPLEMENTARY NOTES

19. KEY WORDS (Continue on reveree side if neceeeary and Identify by block number)
Airborne Equipment Dielectric Withstand Voltage Partial Discharges
"Cables Generator Coils Partial Discharge Tests
"Cable Assemblies I;npul se Tests Pulse Tests
Capacitors High Voltage Transformers
-!Connectors High Power Sources
20. ABSTRACT (Continue on reveres elde It neceeeary end Identify by block number)
-7 he High Voltage Design Guide and High Voltage Specifications and Tests
ocuments referred to in this report pertain to high voltage/high power airborn
equipment. A test plan was designed to evaluate and verify test parameters
specified in these documents. This was done by writing detailed test procedure!
obtaining representative test samples, and testing the specified parameters.
, This report is ' 1son
i- of the High Voltage Specifications and Tests document
(AFAPL-TR-79-20:... which flects the findings of the High Voltage Testing
n of the program.
DD IJAN
-; •:Unclassified
1473 D EDITION, OF, INOV
JN 63 IS OBSOLETE
SECURITY CLASSIFICATION OF THIS PAGE (Whaet Data Entered)

,, ~~~~~~~~~~~~~...........
,,..:.., . ........ ...........--.. :..... :
FOREWORD

Presented herein Is the Boeing Aerospace Company's Final Report coverin ork
accomplished on Contract F33615-79-C-2067 for the period of September 1979
through April 1, 1982. This contract is being performed for the Aero Prolusion
Laboratory Air Force Wright Aeronautical Laboratories, Air Force Systems Command,
Wright-Patter~on AFB, Ohio. The program is under the technical direction of Daniel
Schweickart, AFWAL/P00S-2.

Personnel participating in this work for the Boeing Aerospace Company were W.G.
Dunbar, the technical leader, and S.W. Silverman, the program manager.

:.4"

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-• iii
TABLE OF CONTENTS

SECTION PAGE

1.0 PROGRAM OB3ECTIVES I

2.0 SCOPE 3

3.0 BACKGROUND 5

4.0 TEST DATA TO UPDATE THE ENGINEERING TEST AND SPECIFICATION


CRITERIA DOCUMENTS 7

4.1 INSULATION RESISTANCE 8

4.2 DIELECTRIC WITHSTANDING VOLTAGE 9

4.3 PULSE TESTS 10

4.3.1 PULSE TRANSFORMERS 11

4.3.2 ALTERNATOR PHASE COiLS 12

4.4 PARTIAL DISCHARGE TESTS 13

4.4.1 DC TESTS 13

4.4.2 AC TESTS 13

5.0 CONCLUSIONS 17

Appendix

A CABLES 19

B CABLE ASSEMBLIES 59

C CAPACITORS 91

D CONNECTORS 165

E CONVERTERS 195

F AIRCRAFT HIGH VOLTAGE ELECTRIC POWER CHARACTERISTICS 257

G POWER SOURCES 285

H TRANSFORMERS AND INDUCTORS 371

i.
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Z

LIST OF ILLUSTRATIONS

FIGURE PAGE

3.01 High Voltage/High Power Airborne System 6

Al Stripping Dimensions for CabJes 41

A2 Typical Test Fixture For Use With Cables 42

A3 Test Equipment For Capacitance Test 45

A4 High Temperature And Altitude Test Setup 47

A5 Pulse Test Voltage Profile 48

A6 Typical Mechanical Release Fixture 50

A7 Suggested Method for Making Cable Ends Corona Free 56

BI Solder Contact (Pin and Socket) Configuration 67

B2 Bonding Test 73

B3 Bonding Test (Nondestructive) 74

B4 Basic Insulator Level Test Voltage Profile 85

Cl Typical Production Dielectric Absorption Test Method 138

C2 Pulse Test Voltage Profile 144

C3 Intended Operating Temperature 147

C4 Permissible Operating Voltage at Altitudes From 53,000 to

C5 Permissible Operating Voltage at Altitudes Other than 80,000 Feet 150

C6 Graphical Representation of Minimal Insulation 151

C7 Life at Temperature and Voltage Relative to Percent Rating 152


C8 159
C8 Style Capacitors 159

C9 Style Capacitors 159


DI Solder Contact (Pin and Socket) Configuration 172

D2 Pulse Test Voltage Profile 189

El AC Limits For Constant Overvoltage or Undervoltage 206

E2 Envelope of AC Voltage. Transient 207

vi
LIST OF ILLUSTRATIONS (CONT.)

: -..- FIGURE PAGE

E3 DC Limits For Constant Overvoltage or Undervoltage 208

E4 Envelope of DC Voltage Transient 210

E5 Distortion (Ripple) Spectrum of DC Voltage 211

" E6 Converter Current Carrying Capacity 231

E7 Transient Susceptibility 245

FI Phasor Diagram Showing Required Phase Sequence Relationship 269

F2 Distortion Spectrum of AC Voltage 271

F3 Limits of Frequency Deviation 272

F4 Envelope of AC Voltage Transient 273

I' F5 AC Limits For Constant Overvoltage or Undervoltage 2741

F6 Distortion (Ripple) Spectrum of DC Voltage 276

F7 Envelope of DC Voltage TRansient 277

F8 DC Limits for Constant Overvoltage or Undervoltage 278

F9
Fj Example For Spike Waveform Showing Time Parameters 291
GI Envelope of AC Voltage Transient 304

G2 DC Limits for Constant Overvoltage or Undervoltage 314

G3 RAM Air Transportation Limits 317

G4 Blower Air Temperature Limits 3aX

HI Three-Phase Transformers Without Taps 37.1

H2 Measurement of SRF 414

H3 Electrostatic - Shielding Circuit 414

H4 Loads 416

H5 Polarity for Alternating Voltage Test 1:16

H6 Connections For the Excitatien Test of a Single Phase Transformer 416

H7 Network For Testing and Determining Waveform Parameters 422

1 Vii

-. *-%.'%, . .46%.
N1

LIST OF ILLUSTRATIONS (CONT.)

FIGURE PAGE

HS Examples of Pulse-Rise-Time Determination 423


H9 Examples of Pulse-Duration Determination 424

HI0 Examples of Peak-Pulse Amplitude Determination 424


H 11 Examples of Fulse-Decay-Time Determination 425
H12 Corona Test Circuits 427
H 13 Helmholtz Structure for Magnetic Shielding 440
H14 Center-Tapped Secondary Supplying Unpectified Loads 446
HI Center-Tapped Secondary Supplying Rectified Load 446

H 16 Pulse Waveform 448

A:

:..

-j
LIST OF TABLES

TABLE PAGE
4.1-1 insulation Resistance 8
4.2-1 Dielectric Withstanding Voltage 9

4.,-1 Pulse Voltage 10

4,4-1 DC Partial Discharge Test Data Summary 14


4.4-2 AC Partial Discharge Test Data Summary 15
Al Conductor Data, Concentric Lay Stranded (ASTM B-2861 27

A2 Standard Identification Code 30


,. 3 Materialr, Inspection 34

In-Prc--ess Inspection 34
Qualification Inspection 36

A6 Group A Inspe,.'tion 37
A7 Group B Inspection 38

Pulse Test Voltages 48


A9 3acket Test Temperatures 51

AIO Group Qualification 57


B1 Examination 78
B2 Qalificat'*on Inspection 79

53 Qwmlification Conformance Inspection 80

C1 Terminal 93
C2 Circxiit Diagram aid N..'mber of Terminals 94

C3 Crhvarterintic 94
C4 OC Vol cage Rating 95
C. Capacitance Toter-ance 95

C6 Vibration Grade 96
C7 F3ilure Rate Leve!l 96

* . . -

.71
LIST OF TABLES (CONT.)

FIGURES PAGE

C8 Qualification Inspection For Capacitors 113

C9 Qualification Inspection For Retainer 118

CIO Group A Inspection 121

Cli Group B Inspection 124

C12 Croup C inspection 126

C13 Dielectric Withstanding Voltage Test Details 130

C15 Life Test in Hours 140

C16 Pulse Test Voltages 143

C17 Terminal-to-Terminal Insulation Resistance 161

C18 Style Capacitors 162

C(9 Case Dimensions and Retainer Part Number 162

C20 Millimeter Equivalent of Decimal Inches 163

DI Wire Range Accomodations 167 •rl

D2 Minimum Contact Spaceing 173

D3 Test Voltage After Humidity 177

D4 Contact Engagement and Separation Forces 178

D5 Qualification Inspection for Solder Contact Connectors 181

06 Group.B Inspection 182

D7 Group C Inspection 183

D8 Temperature Extremes 185

D9 Contac. Retention Axial Lo&ds !85

DIO Dielectric Withstanding Test Voltages 187

DII Basic Insulation Level Voltages 189

El Materials Inspection 221

C2 Qualification Inspection 223

E3 Quality Conformance Inspection 226

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LIST OF TABLES (CONT.)
;:' PAGE
:" •'
-. FIGURES

Pull 240
E4
E5 Packaging Method, Unit Supplementary and Shipping Container
Selection Chart 252

Fl Nominal Voltage Values 263

GI Materials Inspection 332

G2 Qualification Inspection 334

G3 Quality Conformance Inspection 338

G4 Pull 355

G5 Packaging Method, Unit Supplementary and Shipping Container


-.-
Selection Chart 365

HI Grade 373

H2 Class 373

H3 Families 373

" H4 Materials Inspection 392

H5 Qualification Inspection 394

H6 Qualification Inspection for Transformer and Inductors Similar


to Transformers and Inductors That Have Been Qualified 396
H7 Group A Inspection 398

H8 Group B Inspection 399

H9 Pull 403

HIO Induced Voltage For Pulse Transformer 408

HI I Packaging Method, Unit Supplementary and Shipping Container


Selection Chart 435

"H12 Transformer on Inductor Data Sheet 453

xi
1.0 PROGRAM OBJECTIVES

The objectives of this program are as follows:

a. Perform high voltage tests on capacitors, cable assemblies and parts, and coils.

b. Design, fabricate, and evaluate a high voltage standard test fixture to be used for
measuring the void content in varicus high voltage insulation systems.

c. Specify and procure a 150 KV, 400 Hz power supply for partial discharge
measurements.

d. Update the Tests and Specifications Criteria Documents completed in U.S. Air
Force Contract F53615-77-C-2054 to include the findings from the test article
evaluations.

e. Develop a high voltage generator test procedure.

f. Update the Airborne High Voltage Design Guide completed on U.S. Air Force
contract F33615-76-C-2008.

g. Develop a Spacecraft High Voltage Design Guide.


2.0 SCOPE

The major task reported in this volume is to:

o Update the Tests and Specifications criteria documents completed on U.S. Air Force
Contract F33615-77-C-2054 based on the findings of the testing portion of the
program.

3
3.0 BACKGROUND

In contract F33615-77-C-2054, a High Voltage Specifications and rests criteria document


was written for U.S. Air Force airborne power supplies and cojmponents which supply
megawatts of power at tens of kilovolts to high power/high voltage systems. A
generalized power source and power conditioning system is shown in Figure 3.-4 for a
turboalternator driven system. However, the turboalternator can be replaced with a MHD
power supply, Emphasis has been placed on minimum weight and volume airborne
equipment, which imply compact systems with high density packaging.

The eight criteria documents were written in accordance with military specifications for:
cables, cable assemblies, capacitors, connectors, converters, power characteristicsp power
sources, and transformers and inductors.

Included in each criteria document were high voltage tests and test parameters based on
insulation design parameters and engineering judgment. In this program test articles were
selected which represented components or component parts for the components discusssed
in the criteria documents. Thje selected test articles were:

Cables
Cable Assemblies
Connectors
Alternator Coil (Sections)
Alternator Coils
Transformer Coils
Power Transformer
Pulse Transformers
Capacitors

Each test article was tested for:

Insulation Resistance
Dielectric Withstanding Voltage
Pulse Voltage
Partial Discharge (Corona)

5
Following completion of the test program, the Test and Specification Criteria
documents were updated to reflect the findings of this test program. -';,

TURBINE
FUEL
SUPPLY

GAS GENERATOR

. RECTMPIER/FILTER
0 INVERTER
E.ECTRICAL XFMR FORWMN NE•lWORKS
GEERTO pR* NEWOK CAB LE LOAD
SWITCH. AS REQUIRED BY THE ASSY
LOAD
(IF REQT)
GASTURBINE
ON AIR.REATHING) POWnER CONDITIONING SUBSYSTEM

F*w 3-4: Hlh VoltqeMo PmwA4r6wm SVy

A..

I
4.0 ENGINEERING TESTS AND SPECIFICATIONS CRITERIA DOCUMENT

The document containing the eight Engineering Criteria reports developed for high-
power/high-voltage airborne systems on contract F33615-77-C-2054, "High Voltage
Specifications and Tests (Airborne Equipment)" have been updated to reflect the findings
from tests on several components tested durin•g contract F33615-79-C-2067, "High
Voltage Testing". The test results and findings are discussed in Volume I of this final
report. Those test results which had the greatest impact on the initial assumption and
criteria developed in the published criteria documents include: dielectric withstanding
voltage, impulse voltage, and partial discharges.

The low-voltage test parameters for insulation resistance and capacitance, were also
measured. The capacitance is measured to verify the specified value determined by the
manufacturer and to determine the loading for the high-voltage test equipment.
Insulation resistance tests, though taken at low-.voltage, are a measure of insulation
integrity before high-voltage evaluation. The insulation resistance values must also be
updated in the criteria documents.

-J

1 7
4.1 Insulation Resistance. The test articles were tested at low voltage (500
volts dc or less). 'These tests were used to determine the probability of short
c.rcuits and to determine the current rating for the power source required for
high voltage dc testing. Components and short cable assemblies used in airborne
and ground support high-voltage systems should have insulation resistance read-
ings exceeding ;o00 megohms. All test articles exceeded that value.

Insulation resistance values specified in the criteria documents were compared


to the test data as shown in Table 4.1-h. These data show that the values
specified in the documents are much lower than the values obtained for the test
articles. Therefore, the criteria document data were increased to the values
shown for "New Criteria Document Values" in Table 4.1-1.

TABLE 4.1-1: INSULATION RESISTANCE

Criteria Test New Criteria


Components Document, Data, Document Value
Specified Tested Megohms Megohms Megohms

Cable A-1 Not 2Xl0 6 IXI0/ft. length


Specified
A-3 2XI0 6

Cable Assembly A-I 500 2XI0 6 1X106/ft. length


Capacitors B-I 50,000 1.25X10 5 1XI0 5
B-2 h.0X10 6
B-3 5.6X105

Connectors A-2 500 2.OX10 6 lX10 6

Alternator Coil D-1 Not 0.7 to 2XI0 6 IX104


Specified

Transformer Coil E-2 Not 1000 1000


Specified

*1

71 z8
4.2 Dielectric Withstanding Voltage. All the components tested for dielectric
).'~ withstanding voltage (DWV) passed the specified DWV tests. However, the capaci-
tors were damaged by the test as determined by the high partial discharge tests
that followed. The cable assembly, cable, and connector test values are accept-
able as recorded in the criteria documents. The compared data and new data used
to update the criteria documents are shown in Table 4.2-1.

TABLE 4.2-1: DIELECTRIC WITHSTANDING VOLTAGE

COMPONENTS Rating, Test Voltage Proposed


kV Specified, Passed, Value, % Rated
"__ __ .DC kV kV Voltage
Cable A-I 90 144 144 144 160
A-3 60 100 100 100 160

Cable Assembly A-2 90 144 144 144 160

Connector A-3 60 100 100 100 160


C40

.'!.Capacitor B-! 100 200 200 160 160


B-2 100 200 200 160 160
B-3 80 160 160 128 160

Alternator Coil D-1 2.8 3.6 3.6 4.5 160


z3ctions

Phase-to-phase D-2 29.6 48 24.7(air) 48 160

Pulse E-2 20 40 45 32 160


Transformer

i9

*1

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H ,_
4.3 Pulse Test. The pulse test parameters specified in the criteria documents
are too high. Using excessively high voltage pulses may permanently damage the
insulation system in an otherwise acceptable test article. Pulse test data
corrections to tnie criteria documents are shown in Table 4.3-1.

TABLE 4.3-1: PULSE VOLTAGE

COMPONENTS Rating, Test Voltage Proposed*


kV Specified, Passed, Value, %Rated
DC kV kV kV Voltage

Cable A-1 90 360 120 180 200


failed

Cable Assembly A-2 90 360 120 180 200


failed
Cable Assembly A-4 60 210 50 120 200
68 failed

Connector A-3 60 210 45 120 200


60 failed
Cable A-5 17 34 35 34 200

Connector A-6 17 34 35.5 34 200

Cable Assembly A-7 17 34 34.0 34 200


50 failed failed
Capacitor B-I 100 400 110 175 175
160 failed
B-2 100 400 110 175 175
210 failed
B-3 80 400 51 failed 140 175
C-I 15 60 14.5 27 175
Alternator Coil D-1 2.8 5.6 11 5.6 200
Sections
Phase-to-Phase D-2 29.6 106 50 60 200
60 failed

Pulse Transformer E-2


Primary to ground 20 32 6 failed - -
Secondary to ground 200 320 210 failed - -
Pri-to-sec 20 32 64 25 125
*Selected values based on components not overstressed by the DWV tests of Table 4.2-1.

10
The proposed values fvr the components are easi'y justified since each of these
items must be capable oi withstanding the normal line transien-ts imposed upon
these components. Crowbar circuits and vacuum tube (when used) shorts can
generate transient peak vlues of 160% norm-A line voltage. In addition, insula-
tion systems should be capable ei withstanding short duration peaks (less than
one second) 20% h'gher than the one minute DWV peak voltage.

4.3.1 Pulse Transformer. Pulse tests should not be applied through the pulse
trai-isformer secondary coils. The high inductance of the coils prohibits an" even
voltage distribution across the turns of the coils. Most of the pulse voltage
will appear across the turn near the pulse initiation terminal, with the per unit
volts per turn decreasing toward the grounded termination. The primary coil is
purposely wound with low inductance (few turns) and resistance and must respond
to a direct applied pulse.

Insulation between turns, coils, and the core are designed to withstand the pulse
voltage stresses. Therefore, external pulse tests should only be applied to the
primary and to the insulation between:

a) primary to secondary,
b) primary to ground (core),
c) secondary and primary (tied together) and ground (core).

Secondary windings should be tested by an induced voltage tet. The overvoltage


pulse test to the primary should also be an overvoltage pulse test to the secondary
simultaneously. It would also test the insulation between windings and the
primary/secondary to core (ground).

2%

n*.
4.3.2 Alternator Phase Coils. The test voltage specified in the criteria reports was
calculated using the accepted values developed by the AIEE Rotation Machinery
Committee in 1959. The pulse voltage test values were calculated using the waveform
voltage data for a 1.2 microsecond wavefront is:

rV3 = 1.25 -2(2VL + i) peak voltage

for V = 29.6 kV line voltage


V3 = 1.25 "T(2 X 29.6 +)
V3 = 106 kV peak voltage

It was planned to use this voltage for test to include both fast rise (1.2 microseconds) and
slow ri.e (5 microseconds) pulses and/or multiple pulses, The insulation system is
marginal at 60 kV peak by test using the 1.2 microsecond pulse. This value agrees with
the calculated values from the revised standards are revised at the 1981 lEE Power
Engineering Society Winter Meeting as shown below (reference 1).

For a 1.2 microsecond pulse, the test voltage should be:

et = 1.2 microsecond
SV 2 = 0.5t + 1.9 pulse voltage
= 0.5 (1.2) + 1.9

= 2.5 per unit


v22 S. VL
2.5 -073 X 2.9.6
= 60.2 kV
Calculated value = 60.2 kV

This calcualted pulse value is 200% rated voltage, the same as for cables, connector and
bushings. These data are included as part of the test parameters for pulse testing in the
document "High Voltage Testing; Volume 3, Generator Test Procedure", AFWAL-TR-82-
2057.

I. "Impulse Strength of AC Rotaing Machines", IEEE Committee Report, 1981 Winter


Power Meeting, Page 81, WM182-5.

12

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4.4 Partial Discharge Tests

4.4.1 Tests. In a large system there will be several ac and dc voltage levels. The
component evaluation testing indicates the higher voltage components will have higher
picocoulomb signatures than the lower voltage components. That is, the higher the test
article rated voltage, the higher the number of counts and the higher the maximum
picocoulomb partial discharge. A value of 2 PC/kV is reasonable for large long cables and
very large transformers with life less :han 1000 hours. For longer life components the
count and pico,'oulomb values must be reduced to I PC/kV or less. These values are in
;.3 accordance with equipment in continual operation by U.S. Air Force personnel. A
comparison of the specified, test data findings, and the new criteria document data are
shown in Table 4.4-2.

4.4.2 DC Tests. The ic oartial discharge specified values, test values, and new values
proposed to update specifications for the test articles are iiste.d in Table 4.4-1. Only
three specifications require change: capacitors, alternators, and transformers. The open
coils of the alternator will permit generation of a greater quantity and magnitude of
partial discharges. The capacitor maximum peak values trust be reduced to be more
*consistent with the other jest values achieved. Likewise, the transformer peak values,
based on dc testing, should be increased.

13

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150
5.0 CONCLUSiONS

Based on the test articles evaluated in this program, the following summary
statement, overall conclusions, and results are presenited in Volume I of this
- report and were used to update the Engineering Criteria Reports.

o The high-voltage test articles were subjected to the insulation resistance,


capcitance, dielectric withstanding voltage (DWV), pulse, and partial dis-
charge tests as spezified in the High Voltage Criteria Documents published
in the USAF document AFAPL-TR-79-2024. It was found that the insulation
resistance and capacitance test methods and parameters are acceptable. The
partial discharge and dielectric withstanding voltage test methods are
acceptable, but the parameters must be revised, and the pulse test para-
r ý-". must be revised, as follows:

The dielectric withstanding voltage parameter must be reduced to 160%


component rated voltage.

The pulse peak voltage must be limited to 200% rated voltage. In

addition, the pulse test time-voltage wave shape must be revised to the
acc#'ptable limits of test equipment and instrumentation. However, if more
realistic wave shapes cannot be determined due to lack o! aystem definition,
the standard 1.2 X 50 microsecond pulse shall be used.

0 A new test sequence should be .ollowed. The sequence should be:


insulation resistance
capacitance
partial discharge
dielectric withstanding voltage
pulse
partial discharge

o Based on the test results in this program components passing the DWV and pulse
tests should pass the second partial discharge test with less than 20% increase in
maximum picocoulomb partial discharge magnitude and total number counts in a
one-minute test period.

17
o Part[' discharge magnitudes for the generator coils must be much higher
than for ,hielded or contained components, such as cable assemblies and capacitors.
Picocoulomb values to 500 pc are acceptable for the glass matrix matet •als.

o Generator cable assemblies and connectors must be tested separately and remain
within the acceptable limits for the components.

zn

j4-0, . . . . " '" : ; ' . - - :' , ' , - - - - - . " . . . . " ," i , . .: ." . ' , .. -. - , . . : . ', . . , . . . . .' ' ' ' ' , . . . , . . . . : ' ' '

18
APPENDIX A

HIGH VOLTAGE CABLE CRITERIA DO,.'UMENT

19
CABLE, POWER, ELECTRICAL, INSULATED, HIGH VOLTAGE
GENERAL SPECIFICATIONS FOR
This specification is approved for use by all Departments and Agencies
of the Department of Defense.
I. SCOPE
1.1 Sceop. This specification covers electrically insulated cables-
for use on high voltage, limited life (1750 hours) applications.

1.2 Classification. Cables covered by this specification shall be


classified as flexible high voltage constructions for power, communications,
instrumentation and electronic applications.

Type I -Unshielded
* Type II - Shielded

Grade A - Temperature range - 65 C to 85 C


"Grade B - Temperature range - 650C to 105 0C
Grade C - Temperature range - 65 0 C to 2000 C

Class 1 - Single conductor


Class 2 - Multiple conductor

1.3 Government designation. Government designations will be assigned


to combinations of type, grade, class and size in the following manner:
Example

Upper
Type Temperature Conductor
A .. Limit

"" Spec. No. S--Shielded Nominal L--Low (85 0 C) S--Single


(absence of Diameter M--Medium (105 0 C) M--Multiple
ltr indicates (Millimeters) H--High (200 0 C)
"unshielded).

MIL-C-915E S 40 M S

7.1

...--. ,
1 *.:..: ,2. APPLICABLE DOCUMENTS
2.1 The following documents, of the issue in effect on date of invi-
tation for bids or request for proposal, form a part of this specification
to the extent specified herein.

SPECI FI CATIONS
FEDERAL

O-E-7060 - Ethyl alcohol (Ethanol), Denatured Alcohol, and


Proprietory Solvent.
:QQ-W-343 Wire, Electrical and Nonelectrical, Copper
"(Uninsulated).

"MILITARY
MIL-C-572 Cords, Yarns and Monofilaments, Organic Synthetic
-
Fiber.
MIL-C-915 - Cable, Cord and Wire, Electrical (Shipboard Use).
MIL-W-3861 - Wire, Electrical (Bare Copper).
MIL-C-12000 - Cable, Cord and Wire, Electric, Packaging and
Packing of.
MIL-F-13927 - Fungus Resistance Test; Automotive Components.
MIL-M-20693 - Molding Plastic, Polyamide (Nylon), Rigid.
w STANDARDS
FEDERAL

FED-STD-595 - Colors
FED-STD-228 - Federal Test Method No. 228, Cable and Wire,
Insulated; Methods of Tezting
FED-STD-601 - Federal Test iethod No. 601:, Rubber: Sampllrty
and Testing.
MILITARY
MIL-STD-104 - Limits for Electrical Insulation Color.
MIL-STD-105 - Sampling Procedures and Tables for Inspection
by Attributes.
MIL-STD-129 - Marking fbr Shipment and Storage
MIL-STD-130 - Identifi'ation Marking for U.S. Military
Property.
MIL-STD-202 - Test Methods for Electeonic and Elcctrical
Component Parts.
MIL-STD-461A -Electromagrnetic Compatibility

(Copies of specifications, standards, drawings and publications


required by suppliers in connection with specific procurement functions
should be obtained from the procuring activity or as directed by the
contracting officer).

21

`7-;T
.'.••• : ,'. ,:'''''- ". .' .'."''' .. ,-. .--.. " . .' '. .. .'- .'..... . . -? .. ; , ... • " '.
2.2 Other publications. The following documents form a part of this
specification to the extent specified herein. Uniess otherwise indicated, the
issue in effect on date of invitation for bids or request for proposal shall
apply.
AMERICAN SOCIETY FOR TESTING AND MATERIALS

ASTM-B 3 - Soft or Annealed Copper Wire.


ASTM-B 8 - Concentric-Lay-Stranded Copper Conductors, Hard,
Medium-Hard, or Soft.
ASTM-B 33 - Tinned Soft or Annealed Copper Wire for
Electrical Purposes.
ASTH-B 172 - Rope-Lay Stranded Copper Conductors Having
Bunch-Stranded Members, for Electrical
Conductors.
ASTM-B 173 - Rope-Lay Stranded Copper Conductors Having
Concentric Members, for Electrical Conductors.
ASTM-B 174 - Bunch-Stranded Copper Conductors for Electrical
Conductors.
ASTM-B i89 Lead-Coated and Lead Alloy-Coated Soft Copper
Wire for Electrical Purposes.
ASTM-B 193 Resistivi'y of Electrical Conductor Materials,
Test for.
ASTM-B 228 Concentric-Lay-Stranded Copper Clad Steel
Conductors.
ASTM-B 258 Standard Nominal Diameters and Cross-Sectional
Areas of AWG Sizes of Solid Round Wires Used as
Electrical Conductors.
ASTM-B 286 - Copper Conductors for Use in Hookup Wire for
Electronic Equipment.
ASTM-B 298 - Silver-Coated Soft or Annealed Copper Wire.

ASTM-B 355 - Nickel-Coated Soft or Annealed Copper Wire.


ASTM 0 297 - Rubber Products, Chemical Analysis of.
ASTM-D 470 - Testing of Rubber and Thermoplastic Insulated
Wire and Cable.
ASTM-D 1458 Fully Cured Silicone Rubber-Coated Glass Fabric
and Tapes for Electrical insulation, Testing.

22

-C **_o: '- ",


•-,-
. ' .,
.- .<...............................
, . •. ,,.. ,',
"................"".'.""..""°
'. . ,. . ' . . . .. " ' .. ,. , . ' "..,. , '... " ..
" '
" .
"''"''"
.. ,'. -
""
,-.•
"
ASTM-D 1868 Detection and Measurement of Discharge (Corona)
.;• Pulses in Evaluation of Insulation Systems.

ASTM-D 3382-75 Measurement of Energy and Integrated Charge


Transfer Due to Partial Discharges (Corona) Using
Bridge Techniques.
ASTM-D 3426 - Dielectric Breakdown Voltage and Dielectric
Strength of Solid Electrical Insulating Materials
Using Impulse Waves.
(Application for copies should be addressed to the American Society for
Testing and Materials, 1916 Race Street, Philadelphia, PA. 19103)
INSTITUTE OF ELECTRICAL AND ELECTRONIC ENGINEERS
IEEE STD-4 IEEE Standard Techniques for High Voltage Testing
UNDERWRITERS' LABORATORIES, INC.
(Application for copies of publications should be addressed to Under-
writers' Laboratories, Inc., 1285 Walt Whitman Road, Melvill3, New York 11746 or
207 East Ohio Street, Chicago, Illinois 60611.)
AMERICAN NATIONAL STANDARDS INSTITUTE, INC.
C96.1 - Temperature Measurement Thermocouples
(Application for copies should be addressed to American National Standards
Institute, Inc., 1430 Broadway, New York, New York 10018.)

NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION


Insulated Power Cable Engineers Association (IPCEA)
Publication No. S-66-524 - Cross-linked-thermosetting-polyeth-
ylene-insulated Wire and Cable for the Transmission and Distribu-
tion of Electrical Energy (NEMA Publication No. WC 7-1971).
NEMA Publication
No. 109 - AIEE-EEI-NEMA Standard Basic Insulation Level.
092-57 - Method of Test for Flash and Fire Points by
Cleveland Open Cup.
(Application for copies should be addressed to National Electrical Manu-
facturers Association, 155 East 44th Street, New York, New York 10017.)
(Technical society and technical association specifications and standards
are generally available for reference from libraries. They are also distributed
among technical groups and using Federal agencies.)
Appendix A - High Voltage Cable Assembly Criteria Document.
Appendix C - High Voltage Capacitor Criteria Docuwrent.
Appendix F - Aircraft High Voltage Electric Power Characteris-
tics Criteria Document.
AFWAL-TR-82-2057, V4- High Voltage Design Guide Aircraft
MIL-HDBK-251 - Military Handbook, Reliability/Design Thermal
Applications, 19 January 1978.
AFWAL-TR-82-2057, VS High Voltage Design Guide: Spacecraft

23
3. REQUIREMENTS
3.1 Detail requirements. Detail requirements or exceptions to the
general requirements specified herein shall be as specified by the speci-
fication sheet. In the event of any conflict between the general require-
ments of this specification and the specification sheet, the latter shall
govern.

3.2 Qualificttion. Cables furnished under this specification shall


be products which have been tested and passed the qualification tests listed
herein.
3.2.1 Requalification. Changes in materials and constructions shall
require the written approval of the cognizant government procurement agency.
Incorporation of any changes which have not been so approved shall require
requalification of the cable or groups of cables in question.

3.3 Materials. All materials used in the construction of those cables


requiring qualification shall have the written approval of the cognizant
government procurement agency. In the case of cables or cords not requiring
qualification, approval will not be required, and all materials in these
cables shall conform to the requirements shown in the applicable specifi-
cation sheets.
3.3.1 Conductors.

3.3.1.1 Standard copper conductors. Standard copper conductors shall


be composed of soft or annealed copper strands conforming to ASTM-B 3.

3.3.1.2 High strength conductors. Unless otherwise specified on the


specification sheet high strength conductors shall be composed of 30 per-
"cent conductivity, high strength, copper-covered steel strands conforming
to ASTM-B 228.

3.3.1.3 Tin coating. Tin coating shall be commercially pure tin


conforming to •STM-B 33.
3.3.1.4 Lead or lead-alloy coating. Lead or lead alloy coating shall
conform to ASTM-B 189.
3.3.1.5 Nickel coating. Nickel coating shall confom to Class 2 of
ASTM-B 355.

24
3.3.2 Insulation. The insulation.shall be applied concentrically
about the conductor and so cured, processed, or maintained as to provide
for accurate centering of the conductor and retention of a circular cross-
section. At any cross-section along the length of the completed wire, the
eccentricity of the center conductor shall be less ";han five percent.of
the difference between measured diameter over insulation and measured dia-
meter over conductor. Measurements to determine concentricity shall be
made upon the primary insulation only and shall not include the thickness
of the semi conducting insulation.

3.3.3 Jacket. When a polyamide, poiyvinyl, FEP-fluorocarbon, neoprene,


or TFE-fluoroc-arbn jacket is specified (see 6.2) a tight fi'%ting corcentric
tube shall be applied. The increase in diameter, that is, the differenco
between the measured diameter under the jacket and the measured diameter
over the jacket shall be not less than one millimeter or more than four
millimeters.
3.3.3.1 Polyamide Jacket. Polyamide jacket material shall conform to
type III, grade E, of Specification MIL-M-20693. Unless circuit identifi-
cation is applied to the jacket, it shall be sufficiently transparent so as
not to impair any underlying color coding.

3.3.3.2 Polyvlnyl jacket. Polyvinyl jacket material, shall be a


polyvinyl chloride or its copolymer with polyvinyl acetate.
3.3.3.3 FEP-fluorocarbon jacket. FEP-fluorcarbon jacket material
shall be fluorinated ethylene propylene. Unless circuit identification
is applied to the jacket, it shall be sufficiently transparent so as not
to impair any underlying color coding.
3.3.3.4 TFE-lluorocarbon jacket. TFE-fluorocarbon jacket material
shall be polytetfrafluoroethylene.
3.3.3.5 Neoprene. Neoprene jacket shall conform to MIL-R-3065.

3.3.4 Shields. The materials and constructions for shields of in-


sulated conductors, groups of insulated conductors and overall cable shall
be as required by the specification sheet. When AWG sizes are specified
for wire shields, they shall be in accordance with ASTM-B 258. When a
shield is specifically required, a closely woven braid of coated copper
strands shall be applied to provide coverage of not less than 90 percent
when determined by the following formula:

K = (2F - F2 ) x 300

25
.. . .
Where:
K= Percent coverage.
a = Angle of braid with axis or cable.
Tan a = 2 (D + 2d) P/C.
d = Diameter of individual braid wire, in inches.
C= Number of carriers.
D= Diameter of cable under shield, in inches.
F = NPd/ sin a.
N= Number of wires per carrier.
P = Picks per inch of cable length.

3.3.4.1 Before braiding, strands shall conform to the requirements for


conductors (see 3.3.1). The metallic coating on the copper strands of the
shield shall be similar to the metallic coating of the conductor of the
wire to which the shield is applied, unless otherwise specified. The braided
shield shall not increase the maximum diameters of the type specified by
more than 0.030 inch.
3.3.5 Tapes. Tapes shall be of the material as specified in the speci-
fication sheet or shall be a type approved for the specific cable construc-
tion.
3.3.6 Braids (identification). Colored braids used for conductor
identification shall be of rayon in accordance with MIL-C-572.

3.3.7 Braids (glass). Glass braids for use on silicone insulated


conductors shaIlTbe composed of the appropriate size of either staple or
continuous fiber conforming to MIL-Y-1140.

3.4 Construction.
3.4.1 Conductor stranding. The size and quantity of individual con-
ductor strands and the total circular-mil area of each conductor shall be
in accordance with Table Al, as applicable in accordance with the size
designation specified by the specification sheet.
I)I
3.4.1.1 Concentric-lay-stranded. The length and direction cf lay
and the type and number of joints In concentric-lay-stranded conductors
shall be in accordance with ASTM-B 8 and ASTM-B 286, as applicable.

3.4.1.2 Ro-pe-aX-conductor. The length and direction of lay and the


type and number of individually insulated and uninsulated conductors in a
rope-lay-conductor shall be in accordance with ASTM-B 172 or ASTM-B 173
as applicable.

4.

26
%A7

Table Al- Conductor data, concentric-lay stranded (ASTM B-286).


Conductor Number Strand Conductor Conductor Weight
Size of Diameter, Diameter, cross-sectional per 1000 feet
ASTM-B286 Strands Nominal Nominal area, nominal approximate
designation (minimum) (inch) (inch) (circular mils) (pounds)

12-37 37 0.0126 0.088 5874 20.20


12-19 19 .0179 .091 6088 20.20
14-19 19 .0142 .072 3831 12.65
16-19 19 .0113 .057 2426 7.97
18-19 19 .0100 .051 1900 5.02
18-7 7 .0159 .049 1770 5.02
20-19 19 .0080 .041 1216 3.16
22-7 7 .0126 .038 1111 3.16
22-19 19 .0063 .032 754 1.98
22-7 7 .0100 .031 700 1.98
24-19 19 .0050 .026 475 1.24
24-7 7 .0080 .025 448 1.24
26-19 19 .0040 .021 304 .780
26-7 7 .0063 .020 278 .780
28-19 19 .0031 .016 183 .490
28-7 7 .0050 .016 175 .490
30-7 7 .0040 .013 112 .309

3.J2 Insulation.
3.4.2.1 Extruded insulation. Extruded insulations shall be applied
concentrically and to the dime.sTions required by the specification sheet.

3.4.2.2 Taped insulation. Tapes used as insulation shall be applied


in such a manner that they lie smoothly and free from wrinkles and voids.
The tape width shall be proper for the diameter over which it is applied
so as to minimize splits, creases and edge tears when the completed cable
is subjected to bending. Registrations shall be held to a minimum, con-
sistent with the best commercial practice.
3.4.2.3 Semicon-Inner. An inner layer of semi conducting insulation
(semicon) shall be extended over the center conductor(s) to prnvide a con-
tinuous concentric circular surface f6r bonding of the primaty insulation.

27

• +• .:,•¢:•. ~ ~~:;6-.,,---,' o'. ,- -.. -.-


,- ,.'. ."-. .•., ,- ,.., . . .- •... . .. .. . .. . . . . . . .
3.4.2.4 Insulation-Primary. The primary insulation shall be extruded
over and bonded to tne inner semicon. This construction will provide a
voidless construction in the area of maxirmium electrical stresses. The
primary insulation shall be compatible with the inner semicon to provide
good bonding capability.
3.4.2.5 Semicon-Outer. An outer layer of semicon shall be put over
the primary insulation. This semicon layer should be obtained as an ex-
truded layer with a gooa cohesive bond to the primary insulation. As a
minimum, a semicon ink shall b.e put over the extruded primary insulation
under a semicon tape. The use of tape alone entraps air at each overlap
joint which is susceptive to partial discharging under electrical stresses.

3.4.3 Shielding. Shielding for type II cable shall consist of a


close and unTiorm woven wire applied direcly over the outer semicon layer.
Each carrier shall have no less than five 0.006 inch diameter (number 34
AWG) wires.
3.4.3.1 Splices. Spliced wires shall average no more than 1 per 10
feet of cable.

3.4.3.2 Coverage. The shielding shall provide no less than 90 per-


cent coverage of the underlying sheath. Percent of coverage shall be
calculated as follows:

K =(2F-F 2 ) x 100
Where:
K - Percent coverage
a - Angle of braid with axis of cable

Percent coverage (K) = 100 (2F-F 2 )

Where:
F= NPd/Sin a
Tan a = 2 (D + 2d) P/C
"a = acute angle of braid with axis of cable or cord
d - diameter (inch) of individual braid wires
D diameter (inch) of cable under braid
N= number of wires per carrier
C number of carriers
P = picks per inch of cable or cord length

28
7. .,. - - ; . , ""7."
I..]
3.4.4 Centering and Circularity

3.4.4.1 Insulation. The insulation over the inner semicon and in-
A
,:• dividual conductors shall be uniform in diameter throughout the conductor
length. At any cross section, the maximum wail thickness shall not exceed
the minimum by more than 10 percent for specified thickness greater than
0.25 inch, nor by more than 20 percent for specified thicknesses of 0.25
inch and less.

3.4,4.2 Cable or cord jacket. The cable jacket shall be applied


concentrically to the cable core in a manner to maintain circularity in
the completed cable. The maxiwum wall thickness of the jacket at any crss
section shall not exceed the minimum by more than 25 percent.

3.4.5 Dimensional tolerances. Where minimum or maximum dimensions,


or both, are specified, no minus or plus tolerances, respectively, will be
permitted. Where a dimension is specified as nominal, the average dimension
shall be not less than the specified nominal. Where no minimum overall
cable diameter is specified, the minimum permissible diameter shall not be
less than 92-1/2 percent of the specified maximum overall cable diameter.
3.4.5.1 Conductor insulation wall thickness. For conductor insula-
tion wall thickness specified as nominal, tMe average thickness shall be
not less than the specified nominal. The minimum thickness, measured at
any cross section, shall be not less than 90 percent of the specified
nominal.

3.4.5.2 Cable jacket thickness. The average thickness of a cable


"jacket measured at any cross section shall be not less than the specified
nominal. In case of multiconductor cables the jacket thickness shall be
determined from the measurements made at the high point of each conductor
taken on a line through the center of the cable and through the center of
the cable and through the center of each conductor in the outer layer.
The minimum thickness at any cross section shall be not less than 80 per-
cent of the specified nominal.

3.4.6 Identification codes and methods. Individual conductors and


groups of conductors shall be separately id.ntified. The applicable identi-
fication code and the method by which the code is applied shall be specified
in the specification sheet.

3.4.6.1 Identification codes.


3.4.6.1.1 Standard identification code. Standard identification code
shall be in accor-ance with table A2.

29

. ..- .. . . .. . . . ..
Table A2. Standard Identification Code

Identifier Base color

1 Black
2 White
3 Red
4 Green
5 Orange

3.4.6.2 Manufacturer's identification tape. Unless otherwise indicated on


the specification sheet, all cables shall contain a continuous, thin, moisture-
resistant marker tape, a shrink-fit marking material, not less than 1/10 inch
wide. The marker tape shall be placed directly over the cable Jacket unless
otherwise approved. The tape shall be printed to show the following information
at intervals not greater than one foot: Name and location of manufacturer; year
of manufacture; specification number (MIL-C-915); and progressive serial number.
The serial number is not to be mistaken for a footage marker. A serial number
shall not be repeated by a manufacturer in any one year for any one type and size
of cable or cord.

3.4.7 Surface condition. The surface of the cable jacket of all shielded
and unshielded cables shall be dry and free from any coating, film or treatment
which v•uld tend to interfere with the bonding to it of encapsulating or molding
materials normally used in splicing and terminating.
3.5 Electrical operational requirements. Unless otherwise specified (see
3.1), the -e-ectrical operational requirements shall be as specified herein.

3.5.1 Continuity. When cables are tested as specified in 4.8.2, each


conductor and shield Shall be continuous.
3.5.2 Spark tests. When cables are tested as specified in 4.8.3, there
shall be no breakdown, flashover, or sparkover.
3.5.3 Voltage withstanding. When cables are tested as specified in 4.8.4,
there shall be no 5reakdown, flashover, or sparkover.
3.5.4 Insulation resistance. When cables are tested as specified in 4.8.5,
the insulation resistance per 1,000 feet shall be as specified (see 3.1).
3.5.5 Partial discharge test. When cables are tested as specified in
4.8.6, the partial discharge extinction voltage shall be as specified (see 3.1).
When specified (see 3.1), the partial discharge extinction voltage test shall
also be performed at simulated altitude levels and the partial discharge extinc-
tion voltage shall be as specified (see 3.1).

3.5.6 Capacitance. When cables are tested as specified in 4.8.7, the


capacitance shall be as specified (see 3.1).

I •i,••z)• ... ;.• ..


,..=.• ,. ,- .. .*-5
... .. ,......... .,..,.,. ... - ,........--.-..,,.,,.......,..-. .- .,-• ,-,-...
with 3.5.7 High temperature and altitude resistance. When tested in accordance
. with 4.8.8, cable shall evidence no sheath or insulation breakdown or corrosion
of the conductor.
3.5.8 Pulse test. When cables are tested as specified in 4 8.9 there
shall be no momentary or intermittent arcing or other indication of fiashover or
breakdown, nor shall there be any evidence of damage.

3.5.9 Ozone. All internal and external materials shall be resistant to


ozone. The man-ufacturer shall certify that all matetials are ozone resistant or
shall perform the tests specified in 4.8.20. There shall be no evidence of ozone
damage to the external surface of the cable.
3.5.10 Electromagnetic compat'bility. When cables are tested as specified
in 4.8.21, the cable shall have a shielding effectiveness of 15 dB minimum, and
electrical field effectiveness of 45 dB mninimum.
3.6 Physical operational requirements. All physical operational require-
ments of the completed cable and cable components shall be as required by the
specification sheet.

3.6.1 Diameter measurements. When cables are examined as snecified in


4.8.1.1, the diameter measurements shall be as specified (see 3.1).

3.6.2 Out-of roundness of jacket measurements (when specified, see 3.1).


When cables are examined as specified in 4.8.1.2, the out-of-roundness of the
jacket diameter dimensions shall be as specified (see 3.1).
3.6.3 Eccentricity of inner conductor. When cables are examined as speci-
fied in 4.8.1.3, the displacement of the inner conductor shall not exceed 10
percent of the core radius, unless otherwise specified (see 3.1).
3.6.4 Adhesion of conductors. When cables are tested as specified in
4.8.1.4, the adhesion of the inner conductor to the dielectric core and the
adhesion of the dielectric core to the outer conductor shall be as specified (see
3.1).
3.6.5 Mechanically induced noise voltage (for low noise cables only). When
cables are tested as specified in 4.8.10, the mechanically induced noise voltage
shall not exceed the specified value (see 3.1).

3.6.6 Aging stability. When cables are tested as specified in 4.8.11,


there shall be no evidence of cracks, flaws, or other damage in the jacket
material.

3.6.7 Stress crack resistance. When cables are tested as specified in


4.8.12, there shall be no evidence of cracks, flaws, or other damage in the
jacket material.
3.6.8 Outer conductor integrity. When cables are tested as specified in
4.8.13, there shall be no evidence of cracks, flaws, or other damage in the outer
conductor material.

31

---------
•.•-•...
.-...-. . .-..... :.. .;.................-.....:............-...---....•--.-. ?. •.-..... ....
3.6.9 Cold Bend. When cables are tested as specified in 4.8.14, there
shall be no evidence of cracks, flaws, or other damage in the jacket material
of flexible cables or the dielectric core material of flexible or semirigid
cable

3.6.10 Dimensional stability. When cables are tested as specified in


4.8.15, the measurement at each end shall not exceed the specified value
(see 3.1).

3.6.11 Bendability. When cables are tested as specified in 4.8.16,


there shall be no cracks, splits, fracturing, wrinkling, or other damage
in the solid outer conductor material, after being formed around the mandrel
diameter specified (see 3.1).

3.6.12 Flammabilit. When tested in accordance with 4.8.17, no burning


or charred particles shall fall from the cable and the flame shall not
travel along the cable at a rate of more than 1/2 inch per minute.

3.6.13 Fungus resistance. After testing in accordance with 4.8.18


cable shall meet the requirements of 3.5.3.

3.6.14 Anti-icing fluid resistance. When tested in accordance with


4.8.19 cable shall evidence no cracking, breaking, or separation, and shall
subsequently meet the requirements of 3.5.3.

3.7 Repair of insulation or cable or cord jacket. Repair of cable


jacket will not be permitted unless the materials and techniques used are
such that the finished cable complies with all the requirements of this
specification. The materials and techniques used in the repair of either
insulation or cable jacket shall be subject to approval by the cognizant
procurement agency. The frequency of repairs shall be held to a minimum.
3.8 End seals. All cables covered by this specification shall have
both ends of each shipping length sealed to prevent the entrance of moiA-
ture. Materials used for end seals and method of application shall have
the written approval of the cognizant procurement agency.

3.8.1 Shielded cables. All shielded cables covered by this specifi-


cation shall have both ends of the center conductor(s) shorted to the
shield during shipping and storage.

3.9 First article, When specified (see 6.2), the contractor shall
furnish a cable sample for first article inspection and approval (see 4,.M).
3.10 Marking. Cables shall be marked with the part numbpr, military
specification number, manufacturer's code symbol and name, in accordance with
the basic requirements of MIL-STD-130. The marking shall be done in such a
manner as not to permanently indent, deform or otherwise damage the jAcket
or outer covering. The first 25 feet of cable sample unit shall be examined
for the marking requirements. The marking shall be visible and legible from
the outside of the cable, except for armored cables. The marking shall be
legible after the aging stability and stress crack resistance tests. The
following details shall apply:
(a) Cable with jackets whose nominal diameter is greater than 0.15
inch shall be surface marked at intervals not exceeding
2 feet.
(b) Cables with jackets whose nominal diameter is less than 0.15 inch
diameter need not be marked.

32

L ' • '.,. •" ... . .. ... , .............


....... .....-... •.>'............................:•..........
3.11 Workmanship. All cables shall be manufactured and processed
in such a manner as to be uniform in quality and shall be free from any burrs,
die marks, chatter marks, foreign material and other defects that will
affect life, serviceability, or appearance. Workmanship shall be such
as to enable the cable to meet the applicable requirements of this
specification.

4. QUALITY ASSURANCE PROVISIONS


4.1 Responsibility for iaspection. Unless otherwise specified
in the contract or purchase order, the supplier is responsible for the
performance of all inspection requirements as specified herein. Except
as otherwise specified in the contract or order, the supplier may use
his own or any other facilities suitable for the performance of the
inspection requirements specified herein, unless disapproved by the
Government. The Government reserves the right to perform any of the
inspections set forth in the specification where such inspections are
deemed necessary to assure that supplies and services conform to the
prescribed requirements.
4.2 Examination. A sample from each reel shall be examined for
compliance with the requirements specified in section 3 of this speci-
fication. Noncompliance with any specified requirements or presence
of one or more defects preventing or lessening maximum efficiency shall
constitute cause for reJection.

4.2.1 First article inspection. First article inspection shall be


performed on one reel of cable when a first article sample is required.
This inspection shall include the examination of 4.2 and the tests of
4.3. The first article may be a standard production item from the
supplier's current inventory provided the reel and cable meets the
requirements of the specification and is representative of the design,
construction, and manufacturing technique applicable to the remaining
reels and cable to be furnished under the contract.
4.3 Inspection conditions. Unless otherwise specified hercin, all
test inspection conditions shall be performed in accordance with the
test conditions specified in the "General Requirements" of MIL-STD-202,
as follows:

a. Temperature: 25°C + 10C.


b. Relative humidity: 60 percent +15 percent.
c. Atmospheric pressure: 950 + 100 Newtons/squarp meter.
4.4 Materials inspection. Materials inspection shall consist of
certification supported by verifying data that the materials listed in
table A3, used in fabricating the cables, are in accordance with the
applicable referenced specifications or requirements prior to such
Sfabrication.

'I-J
33
-ii

TABLE A3. Materials inspection.


Requirement Applicable
Material paragraph documents
Braids 3.3.6 MIC-D-572
tetrafluorethylene (TFE) 3.3.3.4 ASTM D-3159
Ethylene chiorotrifluoroethylene 3.5.6(m) ASTM D-3275
(E-CTFE)
Fiberglass 3.3.7 MIL-Y-1140
Fluorinated ethylene propylene (FEP) 3.3.3.3 L-P-389
Ozone 3.5.9 4.8.20
Pol yami de 3.3.3.1 MIL-M-20693
Polyvinyl 3.3.3.2
Rubber, insulating synthetic 3.3.3.5 ASTM D-470
Rubber, synthetic, semiconductor 3.4.2.3 FED-STD-601
Shields 3.3.4 ASTM B-258
Wire, copper, bare 3.3.1.1 ASTM B-3
Wire, copper, lead or lead alloy 3.3.1.4 ASTM B-189
Wire, copper, nickel coating 3.3.1.5 ASTM B-355
Wire, copper, tin-coated 3.3.1.3 ASTM B-33
Wire, steel, copper-clad ?.3.1.2 ASTM B-228

4.5 In-process inspection. During the manufacturing of cable, the


tests in table A4 shall be performed, as applicable. Tests shall be per-
formed on each continuous length of cable.

4.5.1 Failure. One or more failures shall be cause for refusal,


except a spark test failure may be repaired or the cable length cut out.

TABLE A4. In-process inspection.

Requirement Test
Tests paragraph Paragraph
Continuity 3.5.1 4.8.2
Spark test 3.5.2 4.8.3
Voltage withstanding 3.5.3 4.8.4
Insulation resistance 3.5.4 4.8.5

34

!5,'- , . ., .
4.6 qualification inspection. Qualification inspection shall be
performed at a laboratory acceptable to the Government (see 6.2) on
sample units produced with equipment and procedures normally used in
production.
4.6.1 Sample. The sample of each cable type submitted for
qualification inspection shall be of sufficient length to perfonr, a'.
the applicable tests in table AS.
4.6.2 Inspction routine. The samples shall be subjected to the
inspections specifie in table A5. The entire sample shall be subjected
to the inspection of group I. The specimen length shall be cut from
each sample as required, and subjected to inspections of group II.
4.6.3 Retention of qualification. To retain qualification, the
supplier shall foward a report at 12-month intervals to the qualifying
activity. The qualifying activity shall establish the initial reporting
data. The report shall consist of:
a. A summary of the results of the tests performed for
inspection of product for delivery (groups A and B, para-
graph 4.7), indicating as a minimum the number of
lots that have passed and the number that have failed.
The results of tests of all reworked lots shall be
identified and accounted for.
.b. A sunrnary of the results of tests performed for qualifi-
cation verification inspection group C, including the
number and mode of failures. The summary shall include
results of all qualification verification inspection
tests performed and completed during the 12-month period.
If the summary of the test results indicates nonconformance
with specification requirements, and corrective action
acceptable to the qualifying activity has not been taken,
action tu..y be taken to remove the failing product from
the qualified products list.
Failure to submit the report within 30 days after the end of each 12-
.Dnth period may result in loss of qualification for the product. In
addition to the periodic submission of inspection data, the supplier
shall immnediately notify the qualifying activity at any time during the
12-month period that the inspection data indicates failure of the quali-
fied product to meet the requirements of this specification.
In the event -hiat no production occurred during the reporting period, a
report shall be submitted certifying that the company still has the
capabilities and facilities .lecessary to produce the item. if during
three consecutive reporting periods there has been no production, the
manufacturer may be required, at the discretion of the qualifying
activity, to submit representative cables of each type to testing in
accordance with the qualificatior, inspection requirements.

35

•-• • • "•" •'" " " " " ' " '•. . . . . -"..-'I. ".".:'
.. -:.'- .. - - ' -. .-.- '. . " .-. .. .. . .
Table A5: Qualification Inspection
No. of specimens Requirement Test
Examination or test to be tested paragraph paragraph
Group I
In-process Inspection Entire sample 4.5
Continuity Entire sample 3.5.1 4.8.2
Spark test Entire sample 3.5.2 4.8.3
Voltage withstanding Entire sample 3.5.3 4.8.4
%J4
Insulation resistance Entire sample 3.5.4 4.8.5

Visual and Mechanical Examination Entire sample 3.6 4.8.1


Physical dimensions Entire samp,- 3.6 4.8.1
Marking Entire sample 3.10 4.8.1
Workmanship Entire sample 3.11 4.8.1

Group II

Partial Discharges 2 3.5.5 4.8.6


Electromagnetic compatibility 2 3.5.10 4.8.21
Capacitance 1 3.5.6 4.8.7
High temperature and altitude 2 3.5.7 4.8.8
resistance
Mechanically induced noise 1 3.6.5 4.8.10
voltage
Aging stability 2 3.6.6 4.8.11
Stress-crack resistance 2 3.6.7 4.8.12
Outer conductor integrity 9 3.6.8 4.8.13
Cold bend 2 3.6.9 4.8.14
Dimensional stability 1 3.6.10 4.8.15
Bendability 2 3.6.11 4.8.16
lamnmability 1 3.6.12 4.8.17
Funaus 1 3.6.13 4.8.18
Anti-icing fluid resistance 1 3.6.14 4.8.19
Pulse test 1 3.5.8 4.8.9

S .. 36

-. .. .4
..
.~.
.~*
..
.1 * * - . . . .' 4 .
;
'4.7 Quality conformance inspection.
4.7.1 Inspection of product for delivery. Inspection of product
for delivery shall consist of groups A and B inspection.
4.7.1.1 Unit of product. A unit of product shall be at least
100 feet of cable of the same type designation.
4.7.1.1.1 Inspection lot. The inspection lot shall consist of the
number of units of product, offered for inspection at one time. All
of the units of product in the inspection lot submitted shall have been
produced during the same production period with the same materials and
processes.
4.7.1.1.2 Sample unit. A sample unit shall be a unit of product
selected at random from the inspection lot without regard to quality.
4.7.1.1.3 Sample unit size. Unless otherwise specified, the
sample unit size shall consist of that number of sample units required
by the inspection lot size, as determined by the sampling plans in
MIL-STD-I05.
4.7.1.1.4 Specimen. A specimen shall be an individual length of
cable cut from the sample unit.
4.7.1.2 Group A inspection. Group A inspection shall consist of
the Pxaminations and test specified in table A6.
4.7.1.2.1 amplingpian. Statistical sampling and inspection shall
be in accordance wt -105 for general inspection level II. The
acceptable quality level (AQL) shall be as specified in table A6.
4.7.1.2.2 Rejected lots. If an inspection lot is rejected, the
supplier may screen out the defective units, and resubmit for reinspec-
' tion the good lots using tightened inspection. Such lots shall be
separate from new lots, and shall be clearly identified.
4.7.1.2.3 Disposition of sample units. Sample units from which a
specimen has failed any of the group A inspection tests shall not be
delivered on any order, even though the inspection lot submitted is
"acceptable.
"TABLE A6. Group A inspection.
Requirement Test AQL
Examination or test paragraph paragraph (% defective)
Visual and mechanical examination 3.6 4.8.1 1
Physical dimensions 3.6 4.8.1 1
Marking 3.10 4.8.1
Workmanship 3111 4.8.1

4. . 4.

37
4.7.1.3 Group B inspection. Group B inspection shall consist of the
examinations and tests specfi table A7.
4.7.1.4 Sampling plan. Sample units shall be selected from thuse types
covered by a slngle-specification sheet in accordance with table A6 or A7, 3
months after the date of notification of qualification, except when the total
production in a 3-month period is less than two units of product (10,000 feet)
inspection need not be made until either production is at least 2 units of
product or a total of 6 months has elapsed since the inspection was performed in
which case only one sample unit shall be tested.

TABLE A7. Group B inspection.

Requirement Test AQL


Examination or test paragraph paragraph (% defective)
Pulse test 3.5.1 4.8.9
Voltage withstanding 3.5.3 4.8.4
Partial discharge 3.5.5 4.8.6
Capacitance 3.5.7 4.8.7
Stress-crack resistance 3.6.7 4.8.12 4
Outer conductor integrity 3.6.8 4.8.13
Cold bend 3.6.10 4.8.14
Dimensional stability 3.6.10 4.8.15
Bendability 3.6.11 4.8.16

4.7.1.4.1 Sampling plan. The sampling plan shall be in accordance with


MIL-STD-105 for special inspection level S-3. The sample size shall be based on
the inspection lot size from which the sample was selected for Group A inspec-
tion. The AQL shall be as shown in table A7.

4.7.1.4.2 Rejected lots. If an inspection lot is rejected, the supplier


may screen out the defective units, and resubmit for reinspection. Resubmitted
lots shall be inspecting using tightened inspection. Such lots shall be separate
from new lots, and shall be clearly identified as reinspected lots.

4.7.1.4.3 Disposition of sample units. Sample units from which a specimen


has failed any of the group B inspection tests shall not be delivered on any
order, even though the inspection lot submitted is accepted.

4.7.3 inspection of preparation for delivery. The sampling and inspection


of the preservation-packaging and internal packaging marking shall be in accord-
ance with the quality assurance provisions of MIL-C-12000.

38

..
....... ~.~.~.... .. ... . . .......
~$-:~* - : -:;
-. - --.-
4.8 Methods of examination and test. Test parameters given in the

,:. following tests are not to be assumed as the cable operating conditions,
temperatures or limits. A method to precondition semirigid cable for
normal use is suggested In this specification (see 6.5). Methods of
examination and test given in the specification shall be the only acceptable
methods unless an aternate method has been agreed to by the qualifying
authority prior to the performance of the test. The test methods described
herein are the prefer.ed methods and shall be the referee method in
cases of dispute.

4.8.1 Visual and mechanical examination (see 3.6). The cable shall
be examined to verify that the design, construction, physical characteristics
and dimensions, marking, and workmanship are in accordance with the
applicable requirements (see 3.4 and 3.6).
4.8.1.1 Diameter measurements (see 3.6.1). Measurements shall be
made on a suitable length (12 inch minimum) of cable taken from the end
of the sample unit. Inner components shall be made accessible by stripping
and removing the outer components carefully so as not to nick, cut, cold-
work, or otherwise damage the component to be measured. Measurement shall
be located 3 to 4 inches apart along the specimen length. Measurements.
shall be made at each point In two mutually perpendicular planes, so that
a total of eight measurements are performed on each specimen. Measurements
shall be made with a mi'crometer caliper or any other instrument of equal
accuracy. Measurements include:

a) Inner Semicon ot'tside diameter and thickness


b) Primary insulation outside diameter and thickness
c) Outer Semicon outside diameter and thickness
d) Shield outside diameter
e) Jacket outside diameter and thickness

4.8.1.2 Out-of-roundness of jacket measurements (see 3.6.2). The out-


of-roundness of the Jacket shall be monitored on a continuous production
basis, and the Jacket diameter shall be as specified (see 3.1). The out-
of-roundness measurements shall be permanently recorded with a device cap-
able of producing continuous graphic records. Two recordings shall b8
made, as nearly simultaneously as possible, of the outside diameter 90
apart and a point in the manufacturing process where further dimensional
change will not occur. The recordings shall be permanent and reproducible
by a common commercial process. Thk? technique used (including the detector,
recorder and associated components) shall have a response capable of
recording changes in the diameter with a sensitivity of 0;001 inch along
the length of cable at whatever speed the cable is traveling. The strip
chart response time shall be compatible with the remainder of the system.
The pen traverse shall be large enough to distinguish changes of diameter
of 0.001 inch. The chart speed relative to the cable speed shall be such
that the recording must be identifiable to within 2 feet of the point on
the cable length measured. Each foot of cable shall be represented by no
less than 0.05 inch of recording paper.

39
I.'

4.8.1.3 Eccentricity of inner conductors (see 3.6.3).


4.8.1.3.1 Procedure. Four specimens, each 1 inch approximately in
length, shall be cut from the end of the sample unit. The outer components
of the cable shall be removed down to the dielectric core. The ends of the
specimen shall be cut squarely and carefully deburred. The eccentricity,
in terms of displacement of length, shall be measured with a machinist's
or toolmaker's microscope, or a comparator, or any other instrument
capableof yield;ng a resolution of at least .0001 inch. At spacings
approximately 45 apart around the periphery of the inner conductor,
measurements shall be taken of the dielectric wall thickness. The thickest
measurement (T.) and the thinnest measurement (Tin) shall then be used
to compute themahsplacement, using the following formula:
% Eccentricity = Tmax - Tmin X 100
Measured diameter of core
The percent eccentricity of the inner conductor shall be within the
specified requirements (see 3.1). Measurements shall include:
a) Inner Semicon
b) Primary insulatton
c) Outer Semicon
d) Jacket
4.8.1.4 Adhesion of conductors (see 3.6.4).

4.8.1.4.1 Specimen.

(a) Two specimens of each cable shall F, cut from the end of
the sample unit. Each specimen sh? I be prepared as shown
in Figures Al-A and Al-B, Stripping shall be done carefully.
For semirigid cables, no more than 0.250 inch uf material
shall be removed at one time.
(b) The adhesion to conductors test shall be performed with a
tensile tester and a test fixture such as shown in Figures A2-A
and AM2-. The diameter of the hole in the test plate shall be
such that there is a clearance of .004 +.001 inch larger than
the diameter of the applicable inner conductor or dielectric
core. The inner conductor or dielectric core extending
through the test plate hole shall be pulled with a constantly
increasing force at a rate not to exceed 0.5 inch per minute.
Avoid sudden pulls and jerking. Conductor adhesion shall be
defined as the highest tensile tester reading obtained when
the conductor-to-core bond is broken. In performing this test
physical handling of the specimen shall be kept to a minimum
to avoid specimen degration. The adhesion to conductor re-
quirement, as noted by the reading on the tensile tester shall
not exceed the specified value (see 3.1).

40
3.00 INCE.--3.00
•.25 4.25

CONDUCTOR

FIGURE Al-A Stripping Dimensions for Flexible Cables.

F DIELECTRIC CORE
L3.00±.25 INCHES 6.00 ±.5O INCHES

NNERj L .500t-.OIO INCHES


CONDUCTOR - 12.70".25 mm) CONDUCTOR

FIGURE A1-B Stripping Dimensions for Semi-rigid cables.

! 41.

• ? • • • N .•: ' ,:.. - .rc----.-,-.= .-.- ,,•.: .-.--...- .-..--..-.--.---.----.-. .


9o

I.f

APPR_OX_ GRIP
40TENSILE TESTER

FORCE GRIP

FORCE FIXTURE

INNER "-a -
CONDUCTOR PLATE
HOLE

FIGURE j•,ATypical Test Fixture for Use with Flexible Cables.

CORE- I ,ooTENSILE TESTER


',• / ,PPROX7- GRIP

•] ... L!Q FIXTURE


;•.•INNER-
;;3 ~~CON4DUCTOt
M.WTO
PAE
PLT OUTER
S' HOLE CONDUCTOR

FIGURE A24B Typical Test Fixture for Use with Semi-rigid Cables.

9%

•J 42
4.8.2 Continuity (see 3.5.1). To establish continuity, 25 volts dc
maximum shall be applied to both ends of each conductor and shield of the
,•'• cable through an appropriate indicator, such as an ohmmeter, light, or
buzzer. The test voltage may be applied to each conductor and each shield
individually or in series.

4.8.3 Spark test (see 3.5.2). The specimen shall be tested for
jacket spark in accordance with method 6211 per FED-S1D-228. A test voltage
(see 3.1) at a frequency between 48 and 62 Hz shall be applied between the
outermost braid or shield and the outcr surface of the jacket.

4.8.4 Voltage withstand. Voltage withstand tests shall be made on


all lengths oR completed cable.

4.8.4.1 Apparatus. The voltage withstand tests shall be made with


alternating potential from a source of ample capacity, but in no case less
than 5 kilovolt-ampere, having a frequency not greater than 500 Hz and a
wave shape approximately a sine wave under all test conditions. The testing
voltage may be measured by means of a voltmeter (mis) connected to voltmeter
coil in the high-tension winding of the testing transformer, or to a separate
instrument transformer.

4.8.4.2 Procedure. The test voltages and dpplV '.-ductor


to ground, conductor to conductor, shield to shield, anI ,. i)
shall be as required by the specification sheet. The , olication
for all voltage withstand tests shall be I minute. i
applied voltage shall be not qreater than 600 volts. if in-
i
crease shall be approximately uniform and not over 100 in
10 seconds nor less than 100 percent in 60 seconds. All unarmored
cables requiring electrical tests for the Jacket shall be immersed
in a grounded water bath for at least 1 hour, and tested while still
immersed, using the water as the ground.
4.8.4.3 Observation. All cable shall withstand without failure
the voltages specified on the specification sheet.

4.8.4.4 Test Voltage. The test voltage shall be 160 percent


nominal operating voltale. Alternating current cables shall be tested
with an alternating current source. Cables to be operated at freavuea41es.
to 400 Hz may need to be tested at 60 Hz, Cables to be operated at
direct current my need to be tested at 60 Nz provided the applied 60 Hz rmt
test voltage is reduced to 35% of the dc test voltage, ie., 'DC
for one minute duration. VAC " -

4.8.5 Insulation Resi;tance. The insulation resistance shall be


determined for conductor Insulation and for c•tbe jackets, when required
*~i by the specification sheqt.

43

314 X!-.
"4.8.5.1 Procedure. The test shall be performed on each length of com-
pleted cable immediately following the voltage withstand test. The leakage
current shall be measured after one-minute electrification with a direct current potential
of 500 volts. Cables with unshielded conductors shall be tested between conductor and a
water bath. Cables with individually shielded conductors shall be tested between
conductor and shield. Where cable jackets have insulation resistance requirements, the
test shall be made between the overall cable shield and the water bath. The conductor or
shield whose insulation is under test shall be connected to the negative terminal of the
test equipment and readings shall be taken after one-minute electrification.
4.8.5.2 Observation. The insulation resistance values at 15.5 0 C shall not be less
than required by the specification sheet. If the measurement is made at a temperature
other than 15.5oC, the manuxacturer shall correct the measured value to 15.5oC. If the
insulation resistance is equal to or greater then that required, whena the measurement is
made at a temperature greater than 15.5oC, no correction iactor need be employed. The
manufacturer shall demonstrate that the correction factor used is accurate for his
insulating compound.
4.8.6 Partial Discharge Test (see 3.5.5). Two specimens shall be tested in
accordance with ASTMD1868, (Circuit, Figure 1). The detector used shall have a
sensitivity of less than 1.0 picocoulomb before it is loaded with the test specimen. The
detector amplifier shall have a uniform frequency response up to 500 kilohertz. The
following details shall apply:

a. Magnitude of test voltage - 100% rated voltage.


b. Nature of potential-dc; AC may be used, properly rat#--.'" •. rated equipment
shall not be tested with dc.
c. Duration of application of test voltage - partial discl. .- all be measured
for 3 minutes after operating voltage is attained. Vcdias. anail be increased
from 0 to operating test voltage at rate of 500 volt, per second.
d. Points of application of test voltage - center conductor to shield.
e. Examination after test: cables shall be visibly examined for evidence of
breakdown, arcing, or other visible damage.
f. Partial discharges shall not exceed the following limits.

Voltage limit Counts/Minute Not to exceed


kV PC/kV over limit PC/kV
DC 1 1 5
AC 2 10 5

4.8.7 Capacitance (see 3.5.6). The cable shall consist of a 10-foot 2-inch length of
completed cable with all shields removed for a distance of 1 inch from each end and the
insulation removed from a distance of 1/2 inch fromr each end of all conductors. The
length of the specimen shall be the shielded length.

44

--........ .-...-.-. -.. .. ....... ... ................


4.8.7.1 Test equipment. A Q-meter and oscillator equipped with
the external balance circuit, as shown on figure A3 is recommended.
Other equipment may be used where it can be demonstrated that such
an alternate will yield equally accurate results.

T3 T4 _T.

C
L4"

-j _______________ 12XTERNAL
T BALANCE
CIRCUIT

L: Coil, of inductance suitable for the magnitude of the


reactances to be measured.
C: Variable calibrated precision condenser.
T, and T2 : Terminals of Q-meter-Tl grounded.
- T3 a~nd T4 : Terminals in the inductive branch of the balance
3 circuit. (T4 can be identical with terminal T,.)
S: Means of connecting T3 to T4 .

Figure A3- Test equipment for capacitance test.


The leads from L and C to the Q-neter terminals shall be as short as
practicable. The test specimen of leads fromn the specimen shall be
terminated at or as near as possible to the terminals of L.

4.8.7.2 Procedure. The shield at each end of the conductor


under test shall be grounded. Measurements shall be made for each
shielded conductor using the frequency required by the specification
sheet. Proceed as follows for each conductor of the specimen:

(a) Connect terminal T3 to T4 .


(b) Balance the circuit to resonance (maximum reading on the Q-meter)
by adjusting C. Designate this reading of C as Ch to
(c) Connect the conductor to terminal T2 and the shield to terminal
T1 •
Balance the circuit by adjusting C to a new value. Designate
this value as CI.

-I .44r,

J! 6,r.
4.8.7.2.1 Calculation. The capacitance (C) per foot, for each conductor,
shall be determined by the formula;
(C - C)
(length of specimen in feet)
4.8.8 High temperature and altitude test (see 3.5.7). The cable shall
consist of a 4% foot length of cable prepared in accordance with Figure A4.
The test assembly mounted on the mandrel, shall be placed in a circulating
air oven capable p- reaching a temperature of 200 +2oC for grade C cable,
105 +2oC for grade B cable, and 85 +2oC for grade A cabl- within a period
of not less than I hour or more than-3 hours. The specimen shall be subjected
to this temperature for a period of 125 hours.
4.8.8.1 Voltage application. Rated voltage, at a frequency of 60 Hz,
shall be applied for the first and last 5 hours of the 125 hour test specified
in 4.8.8. The initial voltage application shall be made at room temperature
simultaneously with the start of the oven heating units. At the conclusion
of this test, the insulation, braid, and shecath shall be examined for damage
that might affect subsequent performance.
4.8.8.2 Altitude. At the conclusion of the voltage application test
specified in 4.8.8.1, the test specimen, as set up in Figure A4 shall be
placed in an altitude chamber and the pressure therein shall be reduced to
the equivalent at 70,000 feet + 5,000 feet altitude, and maintained within
these limits for the voltage application test specified in 4.8.8.2.1. The
cable shall pass the partial discharge test at altitude as specified in 4.8.6.

4.8.8.2.1 Voltage application. Rated voltage, at a frequency of 60


Hz, shall be applied between the cable conductor and the conduit assembly
as shown on Figure A4 for a period of 2 hours. The specimen shall then be
inspe'.. •,. for evidence of insulation rupture, cracking or other damage.

4.8.9 Pulse voltage test (see 3.5.8). The cable shall be tested with a basic insulation
level (BIL) voltage according to the IEEE-EEI-NEMA Standard Basic Insulation Levels,
NEMA Publication No. 109, dated 3anuary 1941 to the value shown in table XVI. The BIL
shall be in accordance with the following definition:

"Basic pulse insulation levels are reference levels expressed as pulse crest voltF -,e
with a standard wave not longer than 1.2 microseconds rise and 50 microseconds
decay (Figure AS). Apparatus insulation as demonstrated by suitable tests shall have
capability equal to, or greater than, the basic insulation level."
The BIL levels upon which the cables shall be tested are given in Table A8.

4.6
'.1

S --, .oc r, ••.- k-


4)..

:47 70 Av

e~~e/rdefiVS/ "?T/

FIGUR~E A4 HIGH TEJ'WERAMUE AND ALTITUDE TEST SETUP (Pav~ C8.8).

47

I~~~~~~~ - - - - . .-. . . .* .. ~
.. .- .- .--
Table Ag: Pulse Test Voltages

; Voltage
Rating Pulse
KV Crest Voltage (Crest)
12.5 25
15 30
25 50
50 100
75 150
100 200
125 250
150 300
175 350
200 400
250 500
300 600

• 1.0
,: 0.9
Normnlwzed
Test 0.5
Volta•.

0 1.2 so
TMie - micwsecondl

Figure AS. Pulse Test Voltage Profile

'.44

'.4

m••-,
444 4 - .. - •-
t.....* . -
4.8.10 Mechanically_nducec, noise volta_ e (See 3.6.5).

4.8.10.1 Procedure. The mechznically induced noise voltage


(see ftgureA6) shall be measured by awinging a weight from a specimen
that has a catenary configuration thftt shall be for.ned by supporting
a 5-foot specimen in a 4-foot span. All the clamps shall be of a
circumferential compression type. A 9-foot specimen shall be prepared
for testing as follows: Remove 2 inches of the jacket from one end
of the cable, leaving the outer bral,. intact; push the i.raid back and
cut off one inch of the dielectric core and the inner conductor;
insulate this open end of core and conductor with lectrical tape
and 'insulation sleeving; pull the braid back down ever this insulated
core and conductor, twist and solder the braid to form an interference
shield; set this end in thL clamp on one post with the interference
shield just sticking out of the clamp; measuring off 5 feet of cable,
set the cable into the other clamp on the outer post. At the end of
the over,.ang attach an applicable connector. This connector will be
used to connect the specimen to the measuring equipment. The weight
used shall be 40 pounds per square inch of cross-sectional area of
the cable. The weight on the cable shall be held tautly at its center
point by a clamp in the same horizontal plane as the cable supports.
The oscilloscope sweep shall be started prior to the release of the
weight. At least 8 seconds of cable sWings shall be record.&d on the
trace. The noise voltage induced by the swing shall be taken as
the peak-to-peak voltage and shall not exceed the specified value
(see 3,5.5).

4.8.10.2 Measurement. An osci)loscope and camera, or stoeage


oscilloscope may be used to record th' generated noise of the system.
The specimen shall be connected directly to the amplifier. The
amplifier shall have a 10 megohm minimun inpujt impedance
and the sensitivity of the amplifier skall be 10 microvolts per
centimeter. The shunt capacitance (including the specimen capacitance)
and the band width shall be as specified in the detailed requirements.
The sweep speed shall be 1 centimeter per second.

4.8.11 Aging stability (see 3.6.7). Two specimens shall be cut


from the sample unit. For cables whose nominal jacket diameter is
0.5 inch or larger, the specimen length shall be 95 +1 feet times the
cable diameter, but not to exceed 100 +1 feet.

4.8.11.2 Procedure. The specimen shall be suspended in a heat


chamber without touch'ng one another or the walls of the chamber and
conditioned for 7 days at the applicable test temperature in table A9.
Test temperatures for cable jacket types not listed in table A9 shall
be as specified (see 3.6.6)1 Heated air shall be circulated so as to
maintain a uniform test temperature. After the conditioning period,
the specimens shall be removed from the heat chamber and conditioned
at room ambient temperature for 4 hours minimum.

49
EIG1

F1(.1.5 onOF rA L
*ETtkt 4POOO

TO. STRAT*4OQ0 OST


CONNECT

CSCtLLOSCOPE

..2
4.8.11.2 Procedure (continued)
(a) Examine the splcimen for cracks, flaws-or other dawage in
the jacket material. For marked cables, examine the marking
for legibility.
4b Followrng the test, the specimen shall be subjected to the
cold bend test (see 4.8.14).
TABLE A9 Jacket test temperatures.

Jacket types C.Temperature

Grade A +85 + 2
Grade B +105 + 2
Grade C +200 + 2

4.8.12 Stress-crack resistance (see 3.6.8). Two specimens,


approximately 3 feet long, shail he cut from the sample unit
for test.
4.8.12.2 Procedures. Clamp one end of. each specimen to a
mandrel whose diameter is three times the nominal jacket diameter
of the cable. Wrap each specimen for 10 turns around the mandrel
Sand clamp the specimen to the mandrel at this point. The specimens
shail be suspended in a heat chamber without touching one another
or tile walls of the chamber and conditioned for 96 hours minimum .at
the temperatures listed in table A9. Heated air shall be circulated
so as to maintain a uniform test temperature. After the conditioning
period, the specimen shall be removed from the heat chamber and
conditioned at mom ambient temperature for 4 hours minimum.
(a) Examine the specimen tor cracks, flaws or other damage in
the jacket materil. For marked cables, examine the marking
for legibility.
(b) Unwind the specimen from the rand-el and examine for cracks,
flaws, or other damage in the jacket material. For marked
cables, examine the marking for legibility,
(c) After the stress-crack resistance test, the specimen shall
be subjected to the cold bend test (see 4.8.14).
4.8.13 Outer conductor integrity (see 3.6.9). Two specimens,
approximately 2 feet long, shall be cut from the sample unit. The
specimens shall be suspended in a heat chamber without touching one
another or the walls of the chamber and conditioned for 1½ hours
minimum at the specifie.,. test temperature (see 3.1), Heated air shall
be circulated so as to maintain a uniform test temperature. After
the conditioning period, the specimens shall be removed from the heat
chamber and conditioned at room ambient temperature for 4 hours minimum.
- Examine the specimens for cracks, flaws, or other damage in the outer
conductor material.

51

- ,,.,,...,. -. : v '.:-'- - .- .-. , - -..- -. -- ..


..- '.' .
"4.8.14 Cold bend (see 3.6.10). Two specimens shall be cut from
the sample unTZ. The speCimen lengths shall be the same as for the
• aging stability,'stress-crack resistance and other outer conductor
integritytests; 'as applicable (see 4.1.11, 4.1.12 and 4.8.13).
4.6.14.1 Procedure.

"(a) Specimens shall be tested in either a straight length,


or inra loosely wrapped coil having a diameter ot not less
than 12 inches.
(b) Place the specimens in a cold chamber and condition them
for 20 hours minimum at -65VC +2vC.
(c) After the conditioning period, remove the specimens from
the cold chamber and immediately wrap them four full,
close turns 3round a mandrel whose diameter is 10 times
the nominal outside diameter of the specimen, and then
subject them to the voltage withstanding test (see A8.4).

Unwind the specimen from the mandrel and, except at the clamping
points, examine for cracks, flaws or other damage, in the outer surface
material.

4.8.15 Dimensional stability (see 3.6.11L. A 5-foot minimum


specimen shall be cut from the sample unit. The ends of the specimen
shall be cut squarely and carefully deburred. The specimen shall be
placed in a heat chamber, coiled ur straight, and conditioned for
6 hours minimum at the applicable test temperature shown in table A9
Heated air shall be circulated so as to maintain a uniform test
temperature. After the conditioning period, the specimen shall be
removed from the heat chamber and conditioned at roon amoient temperature
for 4 hours minimum. Measure both ends of the specimen for protrusion
or contraction of the inner conductor! The measurement at each end
shall not exceed the specified value (see 3.7.14 and 3.1).

4.8.16 Bendability (semirigid, see 3.6.12). Two specimens, each


approximately I foot long, shall be cut from the sample unit. The
middle section of the specimen shall be formed for two complete turns
around a mandrel of specified diameter (see 3.1). (Although no special
tools are needed to guide the cable as it coils around the mandrel,
a mechanism may be provided so as to avoid any damage to the outer
conductor.) Remove the coiled specimen from the mandrel and examine
the outer surface for cracks, splits, fracturing, wrinkling or other
damage.

4.8.17. Flawnability (see 3.6.13). The test specimen shall


consist of a 20 inch length of cable.
4.8.17.1 Apparatus. The testing apparatus shall consist of
a Bunsrn burner having a ¼ 'Inch inlet, a nominal bore of 3/8 inch,
a length of approximately 4 inches above the primary inlets, and
equipped with a wing-top flame spreader having a 1/16 by 2 inch
opening fitted to the top of the burner,

52

•. -•-.•
•:•.• ,,.•.'.:..•v .•-'•" "* :.'
* .. ",- ,.•. ..- ..*.* ... ..- ''.•. .;•'..
* '*.. '° --. *." *.*,.
.*..-.**-'*x..;
. •-
•.i 4.8.17.2 Preparation. The specimen shall be suspended taut in
a horizontal position within a partial enclosure which will allow a
flow of air sufficient for complete combustion but which will be
free from drafts.
4.8."7.3 Procedure. The tip of a 2 inch gas flame, with an
i,.:j inner-cone one-Ithird it height, shall be applied to the center of
the length of cable. The flame'shall be applied for 15 seconds,
after which time the cable shall be observed for evidence of separation
or burning particles, and the rate of travel of the flame along the
cable shall be determined.
4.8.18. Fungus resistance (see-3.6.14). The test specimen shall
consist of a length of cable, 4 feet long.
4.8.18.1 Procedure. The test shall be conducted in accordance
with the applicable provisions of Specification ML-F-13927 except
that no peforomance tet will be conducted during exposure. At the
end of the 90 day test, each soecimenn•hall -be sub.jected to the test
specified in 4.8.4 to determine confomiance to 3.6.14.
4.8.19 "Anti-icing fluid resistance (see 3.6.15). The test
specimen shalTconsist of'a4 foot length-of completed cable.
4.8.19.1 Preparation. The specimen shall be wound on a
mandrel in the same manner specified for the bendability test
specified in 4.8.16.
4.8.19.2 Immersion. The specimen, as thus wound on the mandrel
with metal test sleeve in position, shall be inmmrsed for 18 hours
in anti-icing fluid (50 percent alcohol, 50 percent water) at room
temperature, with not less than 3 inches of each end protruding
above the surface. Anti-icing fluid used for testing shall conform
to Federal Specification 0-E-7060. After immersion, specimen shall
be removed and drained for 30 minutes and subsequently tested in
accordance with 4.8.4 to determine conformance to 3.6.15.
4.8.20 Ozone. Unless certification is provided, cables shall

be tested in c--orance with ASTM D470 using an ozone concentration


of 100 to 150 parts per million (see 3.1 and 3.5.9).

4.8.21 Electromanetic comptibility. The cable shall meet


requirements of RE02 and RE4 tests of MIC STD-461A. When the cable
is subjected to the pulse voltage (rated voltage only) of 4.8.9 or an
equivalent sine wave. The sine wave shall include 100 Hz, 400 Hz,
10003.5.10
of Hz, lOKHz, met. 1MHz, IOMHz and 20MHz. The requirements
100K1z,
shall be

5. PREPARATION FOR DELIVERY


5.1 Preservation-eackaqing. Preservation-packaging shall be
in accordance with MML-C-12000, unless otherwise specified (see 6.1).
- The drum diameter of the unit package (reel or spool types) shall not

53
W: MaN

5.1 Preservation-packaging (continued)


be less than 20 times the nominAl outside diameter of the cable. ,.;,
In any case, the druni diameter shall be large enough to preclude •:Z
the flattening of the cable and to prevent damage to the cable from
reeling and unreeling. The no r of cable lengths on a reel shall
be kept to a minimum consistent with good manufacturing practice.
Only identical type designation cable lengths shall be contained in
any one package punit. For inspection purposes, the ends of all cable
lengths on the package shall be br*ought out from the package and
secured. The center conductor shall bý tied to the shield. The
ends of all cable lengths shall be moisture-proof sealed in accordance
with MIL-C-12000. Reels or spools shall be of a disposable, non-
returnable type.
5.2 Packing. Packing shall be in accordance with MIL-C-12000.
Exterior shipping containers shall contain equal quantities of
identical items to the greatest extent possible.

s .3e Marking. Xn .addition. toany required special marking.


msee 6.2),, the un pacljes .and•,shipping containers..shall be
marked in accordance withiML-STI-129. •Marking shall include the
date of manufacture. Where paper labels are used containin' shipment
marking information, the labels .shall be protected by a transparent
compound to prevent deteriioaton ofthe.eMarkingsý. The marking on
each unit package, reel or spool, shall be located on the flange area
whenever possible and shall be. applied in such a manner designed to
preclude the possib~lity of the:marking.becoing illegible during
its use. Each unit package, reel or spool, shall be marked with the
date of manufacture, total length of cable in the unit package, with
the length of each piece in the. order wound. The following warning
note shrll be marked on each unit package:
WARNING: KEEP ENDS SEALED: MOISTURE DAMAGES CABLE: STORE IN COOL,
DRY LOCATION.

6. 'NOTES
6.1 Ordering data. Procurement documents should specify the
following:

a) Title, number and date of this specification.


b• Title, number and date of the applicable specification sheet.
Complete cable part number (see 1.2.1).
Applicable marking and level of preservation-packaging and
packing, if other than specified in section 5. Specify
desired continuous length and for semirigid cable, whether
cable is to be supplied in straight sections or coils.

""- -

54
_. - .. • .,• --...;;r •L .•• .•._ •o • 2.,
. Z..__
; r. .•.;
7
_:_;¶ :!.r• •_. -..- . •_o
-- °. " .•- - • ° ,

.6.-,2 qualification. With rmpect to products requiring


Squalification, awards 711 be made only for products which are at
time set for opening of bids, qualified for inclusion in
h.ne
applicable qualified products list (QPL) whether or not such products
have actually been so listed by that date. The attention of the
suppliers :is called to this requirement, and manufacturers are urged
to arrange to have the products that they propose to offer to the
Federal Government tested for qualification in order that they may
be eligible to be awarded contracts or orders for the products
covered by this specification.
6.3 Definitions.
6.3.1 Maxium continuous working vnltage. The maximum continuous
working voltage Is that safe voltage that can be continuou:•ly applied
to a cable.
6.3.2 Connectors. The applicable connector series are constructed
"•-cicularly for these cables. Extreme care shall be taken in handling
a coaxial cable for assembly to connectors so as not to work-harden, overheat,
or dima§e the 'cable' cioRPnents.
6.3.3 Minimum recommended bendmandrel radius for normal use.
The minimum recomended bend radius for a cable in normal usage Ts
given on the specification sheet. The radius given is to the outer
surface .of the cable. This minimum bend radius is dependent upon
the material of the outer conductor and its thickness. Do not use
tight bend radii unless the application warrants it. Extreme care
should be taken in the forming to prevent wrinking or cracking.
6.3.4 Oprating temperature range. The operating temperature
range is the limits between which a cable may be operated continuously
without any loss in the basic properties of the cable. This includes
the ambient temperature plus the increased temperature due to inner
conductor operation. This temperature range is just a guideline,
since the mechanical, environmental and electrical requirements of
the application contribute to the allowable temperature range. In
no case should the testing temperatures be considered as the operating
temperature range. Testing is usually done under accelerated
conditions so as to possibly degrade the materials.

6.4 Suggested method for making cable ends corona-free is


shown in figure Al.

- -.
55
-~ s - A
3i

Step 1: Suggested length of cable specimen is 36.00 inches (914.40 nmm)

r 3.00
,,s .. INCHES
o - , I -- 11.z INCHES
I-(3.00 o° -01

Step 2: Remove 3.00 inches (76.20 mm) of Jacket material from each end.

3.00 INCHES 1.00 IutCH 1.00 INCH 3.00 INCHES


(7.02m mm
Ff:5.40 (25.40 mm~)

Step 3: Roll back the braid over the Jacket and trim as shown. Be
careful to avoid breaking any strands. Trim the braid edges
neatly to 1.00 inch (25.40 mm) lengths.
.25 INCH 2.5 INC S. .. 0,,,. 6.00rINCHS • • _ _
II
f••rm - -"2. CHE -J WINCHm}r- lZ4ml i T~gm

1.50 INCHIS .7IC S00mC

Step 4: Trim one end of the specimen to the diamenslons shown and
cover the braid edge and Jacket with a plastic tape as
shown. Wrap an AWG No. 20 copper grounding wire tightly
over the br'aid.

FIGURE A7. Suggested method for making cable ends corona free.

". .. --- ,5 ... .. •• ,. . •-- : . - : .. . : .. . . . . . ,,-.. - - . - .. . . . ,. . - - - - . . . ,


-65
APPENDIX
•i!• PROCEDURE FOR GROUP QUALIFICATION INSPECTION
10. SCOPE
10.1 This appendix details the procedure for group qualification
inspection of cables covered by this specification. The procedure
for extending qualification of the required sample to other cables
covered by this specification is also outlined herein.
20. EXTENT OF QUALIFICATION
20.1 Group Qualification. The cable types listed in table AIO
are eligfble for group qualification.
similar characteristics The groups
and requirements. At the are based on
discretion of the
Government, qi!alffication may be extended to cover any or all cable
types in a group, based on compliance of one cable type in that group
with the qualification inspection. Tne Government reserves the right
to authorize performance of any or all qualification inspection on
additional types in the group that are considered necessary to the
extension of qualification within aach group. Cable types not
included in these groups are not eligible for group qualification.

TABLE AID. Group Qualification.

Submntssion and qualification of Qualifies the foll6wing


Group any of the following cable types cable types
I TBD TBD

.4

.57

- 6

4 ,.,. T,, :i• ,: . ;,' :: ;: -•-..:.• :•-. .-.-.---.-.- .:.:.-.-..... -.... .:.-..,... - ,,.•. - -,-
r -J•r h

I'

APEDI.
H4.VLAECBEASI•YCIE]ADCJqN

5.9

".4••""..." ' ' . .:


" "'''''''
HIGH VOLTAGE CABLE ASSEMBLY CRITERIA DOCUMENT

1. SCOPE

1.1 This specification covers high voltage,power cable issemblies


with shielded conducturs and connectors for interconnecting high voltage,:
high power limited life (1750 h•urs) electrical and electronic assemliek.

2. APPLICABLE DOCUMENTS

2.1 The following documents of the issue in effect on date of


invitation for bids or request for proposal form a part of this specifica-
tion to the extent specified herein:

SPECIFICATIONS
Federal
T-T-881 Twine, Cotton, Seine
QQ-P-416 Plating, Cadmium (Electrodeposited)
QQ-S-763 Steel Bars, Wire, Shapes, and Forgings, Corrosion
Resisting
RR-C-2/1 Chains and Attachments, Welded, Weldless, and
Roller Chain
Military
fl'-B-121 Marking for Shipment and Storage
MIL-I-3930 Insulating and Jacketing Compounds, Electrical
(for Cables, Cords, and Wires)
MIL-I-7798 Insulation Tape, Electrical, Pressure-Sensitive
Adhesive, Plastic.

STNDARDS

METHOD Rubber: Sampling and Testing


601

60
2.1 (Continued)

STANDARDS
Military
MIL-STD-105 Sampling Procedures and Tables for Inspection
by Attributes
MIL-STD-108 Definitions of and Basic Requirements for
Enclosures for Electric dnd Electru.'ic
Equipment
MIL-STD-129 Marking for Shipment and Storage
MIL-STD-202 Test Methods for Electronic and Electrical
Component Parts
MIL-STD-461 Electromagnetic Interference Characteristics
Requirements for Equipment
MIL-STD-81O Test Methods for Electronic and Electric
Component Parts
MIL-STD-1285 Marking of Electrical and Electronic Parts
(Copies of specifications and standards required by suppliers in
connection with specific procurement functions should be obtained
from the procuring activity or as directed by the contracting officer.)

2.2 Other publications. The following documents form a part of this


specification to the extent specified herein. Unless otherwise indicated,
the issue in effect on date of invitation for bids or request for proposal
shall apply.

NEMA Publication No. 109 EEI-NEMA Standard Basic Insulation

Level
ASTM D470 Testing of Rubber and Thermoplastic
Insulated Wire and Cable
ASTM D1868 Detection and Measurement of Discharge
(Corona) Pulses in Evaluation of
Insulation Systems

61

• 4: ```.```•:••``•``:```.
:`..• .`•:`:cv••<``` -,v ,',.-,V - . "-..--. ..- '.• .-. '." "
-- Y. j,:-:~ "~-i-. -, -- -- -- -'! - -, -- :, -. ý ý-! -,-. .

"2.1 (Continued)

ASTM D3382-75 Measurement of Energy and Integrated Charge Transfer


"Due :.o Partial Discharges (Corona) Using Bridge Tech-
niques

ASTM D3426 Dielectric Breakdown Voltage and Dielectric Strength


of Solid Electrical Insulating Materials Using Impulse
Waves

Connector Criteria Appendix D


Document

Cable Criteria Appendix A


cDcument

"INSTITUTE OF ELECTRIC AND ELECTRONIC ENGINEERS

IEEE STD-4 IEEE Standard Techniques for High Voltage Testing

-7.

St6

S.. . . ,. -. .
' -) 3. REQUIREMENTS

3.1 Detail requirements. Detail requirements or exceptions to the


general requirements specified herein shall be as specified by the speci-
fication shrat. In the event of any conflict between the general require-
ments of this specification and the specific sheet, the latter shall govern.

3.2 Qualification. Cables furnished under this specification shall


be products which have been tested and passed the qualification tests "isted
herein.

3.2.1 Requalificatton. Charges in materials and constructions shall


require the written approval of the cognizant goverrnment procurement agency.
Incorporation of any changes which have not been so approved shall require
requalification of the cable or groups of cables In quastion.

3.3 Description. Cable assemblies shall consist of cables, connec-


tors, duumy connectors, adapters, end terminal 1u93 and caps. Dimensions
and tolerances shall be shown on the detailed specification sheet where
required. Where tolerances are not shown or where those prescribed could result
in incorrect fits, the supplier is responsible for providing tolerances to
insure correct fit, assembly, and operation of each assembly. No deviation
from dimensions or tolerances shown on the d ;-i led specification sheet
is permissible without prior approval of the contracting officer.

3.3.1 Materials. The material for each part of the cable assembly
shall be as specified (see-3.1). When a definite material is not specified,
a material which will enable the element to meat the requirements of this
specification shall be used. Acceptance or approval of a constituent
material shall not be construed as a guarantee of the acceptance of the
finished product. Materials shall conforw but not be limited to the materials
specified for high voltage cables and for high voltage connectors as specified

,-°6

• 63
,'1
4,,

-V

3.3.1 (Continued)
in the High Voltage Cable criteria document and the High Voltage Connector
criteria documfent.

3.4 Construction. The c.ables shall be so constructed that repeated


S bending in any installed position will not be unduly harmful to them.
Strain relief sleeves shall be provided to relieve the bending stress on
A the cables where necessary In their installed position. These strain
relief sleeves shall be provided with proper fastening devices. The
sleeves shall pvevet bending of tiie cable to a radius of less than 4 times
the cable diameter.

3.4.1 Cible body. The cable body shall consist of a shielded single
conductor core. The single conductor may consist of two or more separate
uninsulated conductors whose ends shall be joined together before final
aisserably to fonn a single effect've conductor. The cable shall have the
following coverings In the order indicated, with the last covering ot, the
outside:
ouse:Seconductor compound

",V Insulation
S•miconductor compound
Braid
Jacket Insulation

The copper braid shall be grounded by means of the connector shell. The
outer layer of semlconductor compound shall be treated as a conductor and
shall not extend beyond the cylindrical section of the metal stress cone
in the terminals.

3.4.2 Cable terminals. Each cable shall be tennlnated with plugs


for insertion into high voltage connector receptacles of high voltage trans-
formers or electrical/electronic equipment. The high voltage cable assemblies

64
/•÷?:,:•3.4.2 (Continued)

shIall be so arranged as to paenit their use as either a cathode or anode


cable assembly and to permit their terminating plugs to be used inter-
changeably in the high voltage transformer and other high voltage assembly
housings, length permitting.

3.4.2.1 Pl_ . The phtg mating face shall be a resilient semi-


flexible material withi- a Shore A Durometer range of 35 to 85. The plug
shall be a part of the cable assembly and the material used for insulation
shall be the same as the Lable to which the connector is to be bonded. The
insulation shall fully enclose the base of the socket. The cable and
connector insulation shal1 be molded integrally without cracks or voids
with a seml to the socket and interconnecting wle core. See Connector Criteria
Cocument, Appendix B .
3.4.3 Receptacles. A receptacle shall be a unit which is fixed on
eithoe' the aircraft or electrical/electronic assembly. The molded insert
"shall have one male contact and shall be molded into the steel shell. No
voids or cracks shall exist between the molded insert and male contact
or between the molded Insert and steel sheil. See Connector Criteria Document,
Appendix D,
3.4.4 Shells and coupling rings. Shells and coupling rings shall be

made of normagnetic corrosion-resisting steel in accordance Wth QQ-S-763,


300 series classes.

3.4.4.1 Finish. The resultant finish on all connEctors shall be elec-


trically conductive. The finish of connectors with corrosion-r'esistant materials,
shells and coupling rings, such as aluminum shell be cadmium plated in accordance
with QQ-P-416, Type 2, Class 3, color-black. All other corrosion-resisting steel
connectors shall be passiated, External screws may be stainless steel in lieu
of the finish specified.

3.4.5 Dummy connectors. Duwmy connectors shall be molded from the same type
"insulation material conforming to MIL-I-3930 qualified connector material.

,1 -'-
3.4.5 (Continued)
Dummy connectors shall prevent the entrance of voisture, dirt, or other foreign
material into the specified plug, or receptacle.

3.4.5.1 Attaching means. Dummies shall be attached to the cable by


either a length of cotton twir.e or a brass chain as specified on the
applicable specification sheet.

3.4.5.1.1 Cotton twine. Cotton twine shall conform to T-T-881,


No. 18, and shall be attached to the dummy and cable assembly by means
of a durable knot which will not slip when pulled.

3.4.5.1.2 Chain. Chain shall conform to RR-C-271, type II, class 6,


(safety chain); nominal metal thickness 0.023 inch; approximately 24 links
per foot; and minimum tensile strength of 110 pounds.

3.4.6 Las. A watertight "dummy" cap shall be placed on each plug and each
receptacle for protection during shipment and installation. The cap shall
consist of a rubber plug or receptacle made of jacket material conforming
to MIL-I-3930 and shall be designed to protect the mating surfaces of the
connector from moisture and dirt. Tape shall be wrapped over the joining
seam to hold the cap securely in place and to give additional protection from
moisture and dirt. The tape shall conform to MIL-I-7798 and shall be 0.007
inch thick and 0.75 inch wide. The cap shall not dam- or deform the
connector in any way. Each cap shall have a male sochet (plug end) or female
srcket (receptable end) shorted to the moetal coupling ring. This shorting
bar is to protect personnel from hazardous charge buildup during shipping
and storage.

3.4.7 Pins and sockets. Pins and sockets of the molded connectors,
inserts, and adapters shall be centered, anchoredg and molded perpendicular
to the face of the compoiient so that they will not loosen by repeated connec-
tion and disconnection with other electrical connectors. There shall be
no intrusion of insulation or foreign material into the socket. Contact
dimensions shall be as specified in Figure B-1. The iiurtration shown on

66

......................................
%
0.D3 MAX DIA VENT HOLE SHELL SEE DETAIL 6
.06 MINl \VOR SIZES 6,4 AND 0
_----\, TIONAL) $,.•ICAL
APPROX
SPHERICA H
RAO

ilLN \A

SOCKET
E DETAIL A DETAIL B PH

SOLDER CUP PIK.END

A l. C2/i D IE F H a .'
Contaci .di M001
,tax M -. 063 Dpa Plug& rcpt Max plug Dia of
size Dia Dia Dia -.0D0 Min .•LX Min M.x and rcpt flat

16 .0625'. 127 069 .250 096 116 .250 .312 .281 .032 'Max
"4/ 16S• .0625 .127:.069 .250 '.096 .116 .062 .125 .281 .032Max
a I .'094 .1S'.12 T375 . i30.10 .0621.125 .37 5
8 .142 .. 3101.205 .500 '.2431.2509.062 .125 .375 .032 Max
225 ,.44l..328 625 .33 6.021
9?7j.062 .1251 .375 .105
:65 150 .50 tI2 .281 .237?,021
_375_05_02

00 .357 1.597i.464-.625 !.5101.550 .002 .125

1/ A"'-nlies after plating.


2/ Used for calculating mechanical spacing between contacts and between contacts
and shell.
3/ RMpresents the distance from the end of the shell to the point at which the
mating pin engages the socket contact spring.
16S.
4/ Dimensions shown are typical for shell sizes 8S, 10S, 10SL, 12S, 14S and

NOTES:
1. Dimensions are In inches.
2/3 E, radius of cutout optional.
2. Sites 12 and 16: G max = optional.
Sizes 0, 4, and 8: Cutout

FIGURE B-1. Solder contact (ginand socket) configuration

67
3.4.7 (Continued)
figure B-1 are for dimensional purposes only and are not intended to indicate
the design. Applicable t.yz" numbers of contacts shall be as specified on
the applicable figure.

3.4.7.1 Pins. The entering end of the pin shall be hemispherical


with a radius of approximately one-half of the pin diameter.

3.4.7.2 Sockets. The receiving end of the socket shall be rounded


or chamfered for directing and centering the entering pin. Sockets shall
have three slots 0.02 inch maximum width and approximately 120 degrees
apart and shall have circumferential-type retaining springs for maintaining
positive electrical contact between pin and socket. Sockets shall have an
external metallic retaining sleeve or band to prevent distortion of the
socket.

3.4.8 Coupling connections. Threaded coupling rings shall be knurled,


and designed so that the pin and socket contacts shall engage or disengage
as the ring is respectively tightened or loosened. The couplIng rings of
connector plugs shall be captive to the shell. The coupling rings shall
have spanner wrench fittings. Torquelng shall be as specified in the
detailed specification.

3.4.8.1 Safety of coupling rings. All threaded coupling rings shall


be designed for safety wiring. At least two holes shall be provided for
shell sizes 14 and smaller, and at least three equally spaced holes for
connector sizes 16 and larger. These holes shall be of a diameter suffi-.
cient to accommodate 0.032 inch diameter wire.

3.4.8.2 Engagement seal. Connectors shall contain sealing means so


that engaged connectors comply with the requirements specified herein.

'',o

68
0 . .. . .. . . ...... . . . .
%. . . . . . . . . . . . . . .....
. . . . . . . . . .
:t"-*
;p3.4.8.2 (Continued)
The design of the seal shall be such that in mated connectors all air paths
between adjacent contacts and between contacts and shells are eliminated.
There shall be interfacial mating of the engaged connector insert to pro-
vide dielectric under compression of 0.010 per inch length insert minimum.
Connector plus shells with threaded coupling rings shall be provided with
a static peripheral seal to ensure shell to shell sealing.

3.4.8•3---Lubricat4on..
If required by the manufacturer, there shall be
provided a cable assembly connector lubricating compound. There shall be
complete instructions for the application of this lubricating material to
the high voltage connector plugs and inserts.

3.5 Bond between connectors and cables. The bond between a connector
or insert and a cable shall withstand the pull specified on the applicable
specification sheet for 1 minutewithoutmechanical or electrical damage.

3.6 Degree of closure. Molded connectors, adapters, inserts, caps,


and dummy connectors when mated with applicable mating components shall pro-
vide a watertight joint as defined in MIL-STD-108.

3.7 tsenqag•nt. The axial tension required to separate the plug


she"-1 from a receptacle shall be 12 pounds maximum when tested in accordance
with 4.3.1. A thin film insulating grease may be used to lubricate the plug
sirface.

3.8 Electrical operational requirements. Unless otherwise specified


(see 3.1), the electrical operational requirements shall be as specified
herein.

*• .. 9
'4•:';r.:':"",•,-:. :..-+:;'- •:..::,,' ':::•::';• ':.:::"."• .:v. .-. :..". . :.. .. .
3.8.1 Continuity. When cable assemblies are tested as specified in
4.6.4.1, each conductor and shield shall be continuous.

3.8.2 The insuTation resistance at 25 0 C (77 0 F)


Insulation resistance.
shall be greater than 500 megohms when tested in accordance wth 4.6.4 1.

3.8.3 Cable assemblies shall show no


Dielectric withstanding voltage.
evidence of breakdown or flashover when subjected to the test voltages and
altitudes in accordance with 4.6.4.3. Corona shall not be considered as break-
down.

3.8.4 Partial discharges. Cable assemblies shall show no evidence of


material deterioration or damage when subjected to the test voltages and alti-
tudes in accordance with 4.6.4.4.

3.8.5 When cable assemblies are tested as specified in


Pulse test.
4.6.4.5, there shall be no momentary or intermittent arcing or oxher indication
of flashover or breakdown, nor shall there be any evidence of damage.

3.8. Ozone. All internal and external materials shall be resistant to


41
ozone. The manufacturer shall certify that all materials are ozone resistant or
shall perform the tests specified in 4.6.:.6. There shall be no evidence of
ozone damage to the external surface of the cable assembly.

3.8.7 Electromagnetic compatibility. When cable assemblies are tested as


specified in 4.6.4.7, the cable assembly shall have a shielding effectiveness of
15 dB minimum, and electrical field effectiveness of 45 dB minimum.

Operating voltage. The cable assembly shall have an operating voltage


3.8.8
as specified in the detailed specification sheet for a period of 1,750 hours
without any evidence of electrical or mechanical malfunction. The temperature
conditions shall be -55 0 C to +850C.

70

S-;"":"."
•; ':.• -' -. " " . "- '.,''..'.',:-'.'.'."
'. ",.-..'' ,-""", :,'.'.'.'* . . . -"-",",". ''.*' '-.-"-'' - " . '.." .- ,-.,, "
"3.8.9 Operating current. The operating current shall be as specified
in the detailed specification sheet. Peak currents of 50 times operating
current shall not exceed a duration of 100 microseconds, 0.04 duty (2 times
average operating current).

3.8.10 Fault current. The cable assembly shall meet a fault current
of 5,003 times average operating current for a maximum period of 5 micro-
"-"• a seconds, decaying to 0 amperes in less than 50 microseconds.

3.9 Physical operational requirements. All physical operational

requirements of the completed cable assembly shall be as required by the


specification sheet.

3.9.1 Diameter measurements. When cable assemblies are examined as


specified in 4.3.1, the diameter measurements shall be as specified
"(see 3.1).

- :._.: " 3.9.2 Out-of roundness of jacket measurements (when specified, see 3.1).

!•' When cable assemblies are examined as specified in 4.3.1, the out-of round-
ness of the jacket diameter dimensions shall be as
specified (see 3.1).

Eccentricity of inner conductor. When cable assemblies are


3.9.3
examined as specified in 4.3.1, the connector pins and socket shall be
centrally positioned in the plug (socket) and receptacle (pin), unless
otherwise specified (see 3.1).

3.10 Environmental. Unless otherwise specified, the electrical and


mechanical characteristic shall remain within specified tolerances before,
.-. ' during and after cable assemblies are exposed to the following environ-
mental conditions.

3.10.1 Random vibration. When tested as specified in 4.6.5.1, a


current discontinuity of I microsecond or more, disengagement of the mated
connectors, evidence of cracking, breaking, or loosening of parts shall be
cause for rejection of the cable assembly.

71

• % ,; a••,;:;
.- ;'.:;•
..... •-- - ;. - :-% a
.. ...-...a .
a.. .- ". -. ..'.'
a * - . .., .. -....
; .. .. .*. ...
. ... .a ,. , . * a... .a...
3.10.2 Temperature. There shall be no evidence of damage detrimental ,
to the operation of the cable assembly after being subjected to the
temperature extremes in accordance with 4.6.5.2.

3.10.3 Moisture resistance. Cable assemblies shall maintain an insula-


tion resistance of 100 megohms or greater at 25 0 C after being subjected to
the moisture resistance test in accordance with 4.6.5.2.

3.10.4 Salt atmosphere. When tested as specified in paragraph 4.6.5.3,


the cable assemblies shall have no degradation of electrical or mechanical
performance or deterioration of the ability to mate and unmate the connector-
cable assembly. There shall be no evidence of corrosion of bare metals
or plating materials.

3.10.5 Altitude. When tested as specified in 4.6.5.4, the cable


assemblies shall meet the corona and voltage breakdown requirement of 4.6.4.4.
Any evidence of dielectric breakdown or flashover zhall be cause for rejection.

3.10.6 Bonding. The electrical fittings shall withstand the bonding


test as applicable (See FtgureB2 add Figure 83),as specified in 4.6.5.5.

3.11 Marking. Cable assemblies shall be marked with the part number,
military specification number, manufacturer's code symbol and name, in
accordance with the basic requirements of MIL-STD-1285. The marking shall
be done in such a manner as not to permanently indent, deform or otherwise
damage the jacket or outer covering. The marking shall be visible and
legible from the outside of the cable assembly, except for armored cables.
The marking shall be legible after the aging stability and stress crack
resistance tests. The following details shall apply.

a. Manufacturer's name, registered trademark or identification.

b. Date Code. On parts which are reworked,the manufacturer shall


mark a new date code prefixed by the letter "R" without removal
of the prior markings.

72
- -~~~~~ . - - .. . . . . . 4..'-

,I~

,. !I A
U OHTI UFC
; f J'INSULATION

METALO
PUSLEEVE

INSSULATION

OR PAITULA 1/4, IN.


CUT MINIMUMtlll
WIDTH.

METAL PLUG SLEEVE

SECTION IA
iONDIKG TEST (DESTIkJCTIVE)

$t

Figure B-2 BONDIJG TEST

73
:,1

FLEXIBLE
CABLE

MINIMUM SEND
"•AmU. s 3 TIMES
CABLE" DIAMETER

CHECK
B~l~t e-------CABLE

poa EDGE PROBE


(RtIGIO PLASTIC OR METAL)
WITH No, SHARP EDGES OR POLYURETHANE
CORNERS. DO NOT USE
3OMEWORiVER.

PRY I•

METAL PLUG SLEEVE

IF INlSULATIN4G
THE PLUG, ASSEMBLY SHALL PEELS
MIATERIAL BACK TO REVEAL
BE. REJECTED. TEST ,ITAL,
REPEAT BARE AT
FOUR DIFFEREIIT POINTS ALONIG CIRCUtIFEREPCE.

Figure B-3 BONDING TEST (NONDESTRUCTIVE)

74

.'., , . , . , ... ,,,Ox , ,. .. . -. ....... . .\ ..


S..-, 3.12 Workmanship. Loose contacts. poor molding fabrication, loose
, materials, defective bonding, damaged or improperly assembled contacts,
peeling, or chipping of plating or finish. galling of mating parts, nicks
and burrs of metal parts and post molding warpage will be considered adequate
basis for rejection of items of quality inferior for the purpose intended.

" .a.,•.• .. •• • -. :• :5..'. >=••...:,.. , • ..... .. .... . , . .o : .. . .-. •.• . .: .. .. .°...

75
- 4. (.)ALITY ASSURANCE PROVISIONS

4.1 Responsibility for inspection. Unless c•herwise specified in the


contract or purchase order, the supplier is responsible for the performance
of all inspection r.. jireinents as specified herein. Except as otherwise
specified in the contract or order, the supplier may use his own ot any
other facilities suitable for the performance of the inspection requirements
specified herein, unless disapproved by the Goverment. The Government
reserves the right to perform any of the inspections set forth in the
specification where such inspections are deemed necessary to assure that
supplies and services conform to prescribed requirements.

4.1.1 Component and material inspection. The supplier is ,esponsible


for insuring that components and materials used are manufactured, examined,
and tested in accordance with teferenced specifications and standards.

4.1.2 SampliKj. The unit of product for inspection purposes shall be


two cable assemblies.

4.1.3 Tes~t euipment and Inspection facilities. Test and measuring


equipment and 4ispection
fcilities of sufficient accuracy, quality, and
quantity to permit performance of the required inspection shall be estab-
lished and maintained by the contractor. The establishment and maintenance
of a calibration system to control the accuracy of the measuring and test
equt•p ,nt shall be in accordance with NIL-C-4CO66.

4.2 Classification, of inspection. Inspection shall be .14ssified


as follows:

a. jualification W.spection (see 4.3).


b. Quality conformance inspection (see 4.4).
c. Inspectivn of preparation for delivery (see 4.5).

-
4.2.1 Inspection conditions. Unless otherwise specified herein, all
test inspection conditions shall be performed in accordance with the test
conditions specified in the "General Requirement,," of MIL-STD-202, as
follo*S:

a. Temperature: 250 C _ 10°C.


b. Relative humidity: 60 percent +15 percent.
c. Atmospheric pressure: 850 to 11W Newtons/square metev.

4.3 Qualification inspection.

4.3.1 Examination. Each preproduction cable assembly shali be


examined in accordance with table r,-1, Presence of one or more defects in
either preproduction cable assembly shall be cause for rejection of both
cable assemblies.

a"'-.

-7

i7
.° X.~~ iL ŽŽi2
"TABLE B-1 Examination

Conn. Cable Dummy Requirement


Caps assy. Adapter conn. Defect paragraph
x X X Pin or socket coptacts not 3.1
as specified.
X X X X Dimensions not as specified. 3.3
X 180-degree bend at joint 3.4
causing visible separation
of connector and cable.
X X X X Materials or components not 3.4
as specified.
-. x. Bond between cable and 3.4
connectors cracked.
-'X X X Attaching mean3 for duemy 3.4.5
connectors not as specified.
X X X Connectors not electrically 3.7
or physically serviceable
after mating.
X X - - Caps have shorting bar missing 3.4.6
- X X X X Identification mrklngs 3.11
missing or InccWlete.
X X X X Workmanship not as specified. 3.12

4.3.2 Tests. Following successful completion of the examination, the


preproductlrn cable assemblies shall be tested as indicated in table 5-2. Tests
shall be conducted in the order listed. Any test result not meeting the
applicable requiremt paragraph shall constitute failure of the test and shall
be cause for rejection of the preproduction cable assemblies.

4.3.3 WIflcation syple. Preproduction cable azsslies for which


qualification is desired shall be tested in the sequ. nce specified in Table S-2
Specific details on prepp-;tion of samples shall be a follows: Each test
article subjected to qua, icatlon t-sting shall be prc-vided with a counterp&.t
conpector for those tests requiring mating assemblies. The counterpart
coectors provided for this purpose shall be unused, pieviously oualified connectors
or new connectors submitted for qualification testing. Manufacturers not producing
mating connectors shall submit data substantiating that tests were performed
with approved counterpart connectors.

78
Table B-2: Qualification Inspection

Requirement Test
Inspection paragraph paragraph

Hardness Disengagement 3.7 - 3.4.2 4.fi.2 - 4.6.3


Continuity 3.8.1 4.6. .1
Insulation Resistance 3.8.2 4.6.4.2
Dielectric Withstanding Voltage 3.8.3 4.r,.4.3
Partial Discharge 3.8.4 4.6.4.4
Pulse 3.8.5 4.6.4.5
Ozone 3.8.6 4.6.4.6
ýIectromagnetic Compatibility 3.8.7 4.6.4.7
O;!.Pating Voltage 3.8.8 4.6.4.8
Operating Current 3.8.9 4.6.4.8
Fault Current 3.8.10 4.6.4.8.1
Random Vlbration 3.10.1 4.6.5.1
Temperatre and Humidity 3.10.2 4.6.5.2
., Moisture Resistance 3.10.3 4.6.5,2
Insulation Resistance 3.8.2 4.6.4.2
Salt Atmosphere 3.10.4 4.6.5.3
Dielectric Withstanding Voltage 3.8.3 4.6.4.3
Altitude 3.10.5 4.6.5.4
Partial Discharge 3.b.#' 4.6.4.4
Bonding 3.10.6 4.6.5.5

79

...... ,......... ...... ...-.. ,... ......... .


72~J
"" 4.4 Quality conformance inspection

4.4.1 Inspection of product for delivery. Inspection of product for


delivery shall consist of an inspection lot.

4.4.2 Inspection lot. An Inspection lot shall consist of all produc-


tioto cable assemblies covered by this specification, produced under
essentially the same conditions and offered for Inspection at one time.
In-process controls, unrelated to lot sizes of finizhed articles, may be
used, provided an equivalent or tighter inspection level is maintained.

4.4.2.1 Rejected lots. If an inspection lot is rejected, the supplier


may rework it to correct the defects, or sci .en out the defective units and
resubmit for inspection. Resubmitted lots shall be inspected using tightened
inspe .^n. Such lots shall be kept separate and shall be clearly identi-
fied as reinspected lots.

4.4.2.2 Inspection. Inspection shall consist of the applicable tests


specified in Table B3 and shall be made on the units which have been subjected
to and have passed inspection examination of parameters listed in Table B3.

Table 83. Qualification Conformance Inspection

Inspection Requirement Test


Paragraph Paragraph
Dielectric withstanding voltage 3.8.3 4.6.5.4
Corona 3.8.4 4.6.6
Insulation Resistance 3.8.2 4.6.14.2

4.4.2.2.1 ,Dspos•lionof stple units. Sample units which have passed


the inspection rly 1e delivered on the contract or purchase order.

4.4.2.2.2 •n2Mj ance. If a sample fails to pass qualification


conformAnce inspnction, thme manufacturer shall take corrective action on
the mterials or proceises, or both, as warranted, and on all units of
prcduct which can be corrected and which we r-nufactured with essentially

806
4.4.2.2.2 (Continued)
the same materials, processes, etz. and which are considered subject to the
same failure. Acceptance of the product shall be discontinued until correc-
tive Qation, acceptable to the procuring agency, has been taken. After the
corrective action has been taken, qualification conformance inspection shall
be repeated on additional new samples of the final desiqn. Oualification
inspections may be reinstituted; however, final acceptance shall be withheld
until the qualification conformance reinspection has shown that the corrective
action was successful. In the event of failure after reinspection, informa-
tion concerning the failure and correctiv;e action shall be furnished to the
cognizant inspection activity and the qualifying activity.

4.5 Inspection of preparation for delivery.

4.5.1 Quality conformance inspectiLn.


-I

4.5,1.1 Unit of product. For the purpose of inspection, a cumpleted


cable assembly prepared for shipment shall be considered a unit of product.

4.5.1.2 Sampling. Sampling for examination shall be in accordance


with MIL-STD-105.

4.5.1.3 Examination. Samples selected in accordance with 4.5.1.2


shall be examined for the following defects.

161. Materials and containers not as specified for level A or B.


Each incornct material or container shall constitute one
defect.
102. Assemblies plugged together, as required.
103. Ends not secured together with cotton tape.
104. Coils coiled beyond minimum safe diameter.
105. Packaging not as specified.
* 106. Packing not ar specified.
S107. Strapping not zinc coated for level A.
108. Marking illegible, incorrect, incomplete or missing.
109. Cable assembly ends capped, as required.

81

:•:-:.-. .= •,. '.,;, "=4


...•:.,, ,:, ..:,.,.-. , ,, .- ,,- ,, ... .- ***
-4I' 4.6 Methods of examination and tests. A;-

4.6.1 Visual and mechanical examination. The cable assembly


connectors and accessories shall be visually and mechanically examined to
ensure conformance with this specification and the -pplicable military
standards (see 3.1, 3.3, 3.4, 3.11 and 3.12). In-process controls of
component parts, unrelated to lot sizes of finished cable assemblies, may
be utilized in lieu of examination of these components in the finished cable
assemblies to assure conformance of these component parts.

S4.6.2 Disengagement. The cable assembly connctors shall be fully


nated to securely mounted receptacles. A qradually increasinq axial
tension shall be applied to the plugs, and the force at separation measured
(see 3.7).

4.6.3 Hardness of insert or body material. Determine the hardness of


the body material in accordance with FED. TEST METHOD STD. No. 601, method
3021 (see 3.4.2).

4.6.4 Electrical tests. The electrical tests shall be run on each


cable asembly by the manufacturer to demonstrate compliance with the
requirements of paragraph 3.8 of this specification unless otherwise
specified. All electrical tests shall be run with the cable assembly mated
with the receptacle.

4.6.4.1 Continuity (see 3.8o1). To establish continuity, 25 volts dc


maximum shall be applied to both ends of each conductor and shield of the
"cable through an appropriate indicator, such as an ohmmeter, light, or
buzzer. The test voltage may be applied to the conductors and shields
individually or in series.

4.6.4.2 Insulation resistance (see 3.8.2). The insulation resistance


shall be determined for conductor insulation and for cable jackets, when
required by the specification sheet.

82
*J ** . \~.---* . . .*;*~~ * . :....
:•., •,,-, _-.
. -,. .-, . - '-,, ,, . , ., ,. , - ..' . .- , . ..- . -. . . ., :
-,. ,. :, ' .,'. _. ., - ., -. ,. ... .-. - - . . -,,., , " . '. - ' '- ,-.- " ""-"- - " - - -. - . -, "' ---' . : " ' I..
.h'7

4.6.4.2.1 Procedure.
The test shall be performed on each length of
completed cable assembly. The leakage current shall be measured after
1-minute electrification with a direct current potential of not less than
200 nor more than 500 volts. Cable assemblies with individually shielded

conductors shall be tested between conductor and shield. Cable jacket


insulation resistance measurements shall be made between the overall cable
shield and a water bath. The conductor or shield whose insulation is under
test shall be connected to the negative terminal of the test equipment and
readings shall be taken after 1-minute electrification.

4.6.4.2.2 Observation. The insulation resistance values at 15.50C.


shall be not less than required by the specification sheet. .If the

measure•ent is made at a temperature other than 15.5 0 C., the manufacturer


shall correct the measured value to 15.5°C. If the insulation resistance
is equal to or greater than that required, when. the measurement is made
at a temperature greater than 15.5 0 C., no correction factor need be
employed. The manufacturer shall demonstrate that the correction factor
used is accurate for his insulating compound.

4.6.4.3 Dielectric Withstanding Voltage (DWY) (see 3.8.3). OWV tests


shall be made on all crmpleted cable assemblies.

4.6.4.3.1 Apparatus.
The voltage withstand tests shall be made with
alternating potential from a source of ample capacity, but in ro case less
than 5 kilovolt-amperes, having a frequency not greater than 500 Hz and a
wave shape approximately a sine wave under all test conditions. The testing
voltage may be measured by means of a voltmeter (rms) connected to voltmeter
coil in the high-tension winding of the testing transformer, or to a separate
instrument transformer.

4.6.4.3.2 Procedure. The test voltages and application (conductor


to shield and sheld to ground) shall be as required s bw the specification
sheetl The time ol applt cation for all voltage withstand tests shall be
minute.
The initially applied voltage shall be not greeter than 1000 volts.
The rate of increase shall be approximately uniform and not over 100 percent

83

.• °. ". ',.".
. . v. . .• -,.'•.
'o." . • . . . . . . , . . .... . . . , . ..-. -. . -•. °. .. .-. . .
"4.6.4.3.2 (Continuea)

in 10 seconds nor less than 100 percent in 60 seconds. All unarmored cables
l requiring electrical tests for the jacke', shall be immersed in a grounded
water bath for at least I hour, and tested while still immersed, using the
water as the ground.

12 4.6.4.3.3 Observation. All cable shall withstand without failure the


voltages specified on the specification sheet.

4.6.4.3.4 Test voltage. The AC test voltage shall be 160 percent nominal operating
voltage. Alternating current cables shall be tested with an alternating current source.
Cables to be operated at a frequencies to 400 Hz, may be tested at 60 Hz. Cables to be
operated at direct current may be tested at 60 Hz provided the applied rms voltage is
reduced to 35% of the dc voltage, i.e., Vdc = 2N7 Vac for one minute duration.

4.6.4.4 Pzrtial discharge (see 3.8.4). Two specimens shall be tested In accordance
with ASTMDI$68, (Circuit, Figure 1). The detector used stiall have a sensitivity of less
than 1.0 picocoulomb • e It is loaded with the test specimen. The detectorshall have
Sunifoim frequency response up to 500 kiloherz. The following details shall apply:

a. Magnitude of test voltage - 100% rated voltage.


b, Nature of potential-dc. AC test may be used, iroperly rated. AC equipment
shall not be tested with DC,
c. Duration of applicatic,- of test voltage - partial discharges shall be measured
for 3 minutes after operating voltage is attaL•ed. Voltage shall be Increased
from 0 to operating test voltage at a rate of 500 volts per second.
d. Points of application of test voltage - center conductor to shield.
e. Examination aUtv test: cable assemblies shall be visably examined for
evidence of breakdown, arcing, or other visable damage.
f. Partial discharges shall not exceed the following limits.

Voltage limit Counts/Minute Not to exceed


kV P uver limit PC&kV

DC 1 15
AC 2 10 5

84
4.6.4.5 Pulse voltage test (see 3.8.5). The cable assembly shall
be tested with a basic insulation level (BIL) pulse voltage according to the EEI-NEMA
"StandardBasic Insulation Levels, NEMA Publication No. 109, dated January 1941. The
BIL shall be in accordance with the following definition:

"Basic pulse insulation levels are reference levels expressed as pulse crest voltage
with a standard wave not longer than 1.2 x 50 microseconds (1.2 microseconds rise
and 50 microseconds decay, Figure B4). Apparatus insulation as demonstrated by
suitable tests shall have capability equal to, or greater than, the basic insulation
level".

The pulse levels to which the cable assembly shall be tested are 200 percent rated peak
voltage.

1.0 I ""'

* rMWOR'.ALIZED 0.5--1
VOLTAGE

1.2 5

TIME - MICROSECONDS

FIGURE 54. Basic insulation level test voltage profile

4.6.4.6 Ozone. Unless certification Is provided, the cable assembly shall be tested
in accordance with ASTM D470 using an ozone concentration of 100 to 150 parts per
million (see 3.1 and 3.8.6).

85

~~~~~
. .

. .
eo. ..- •.
.
-,• o."
• - .°
,.•'
.
+ -o • -
. .••.
. oO °,. ..
.,•.
o . .
.
- %
.
.-.
. .
-
.
o-.-
.

...
.
.•
.••%-
.
."
.o
-o
.

.
- •
- ..- -•-o.
o+
.
-.
•.
..
-.-
.
o
.•. •
*
% .


o-o
•- .•
°
%
4.6.4.7 Electromagnetic compatibility (see 3.8.7). The cable
assembly shall meet the requirements of REO2 and RE04 tests of MIL-STD-461A.
When the cable assembly is subjected to the pulse voltage (rated voltage
only) of 4.6.4.5 or an equivalent sir.n wave. The sine wave shall include
100 Hz, 400 Hz, 1000 Hz, IOKHz, 100KHz, 1MHz, lOMHz and 20 MHz.

4.6.4.8 Operating. Connect the cable assembly to a power source and


dummy load, and check for operation at rated voltage and current. Connect
and disconnect the connectors five times. Short circuits, open circuits,
arcing during operation, or failure of the connector to connect or dis-
connect shall constitute failure of this test.

4.6.4.8.i Fault current. Connect the cable assembly to a low-voltage,


high-current power source and duwmy load, and check for fault current
operation (see 3.8.10).

4.6.5 Environment tests. The following tests shall be conducted on


the first production item in accordance with conditions specified below to
assure compliance with the environmental conditions of this specification.
The sample subjected to these tests shall remain in a safe place, at the
manufacturer's facility and to be made available to the procuring agency
upon request in writing. The manufacturer is responsible for the safe
keeping of the test sample for a period of 2 years.

4.6.5,1 Vibration. Install a mating plug on each end of the cable


assembly that is provided with a plug. Equip each plug with at least 3
feet of cable with the ends bared. The cable asseribly and accessories shall
be mounted as follows and subjected to the applicable vibration test. Each
cable assmbly shall be mounted on a suitable fixture, which, in turn, shall
be attached to a vbratton table. A suitable sensor shall monitor the
vibration of the cable a=sambly at a point on or near the receptacle.

r 86
. . •5 .-4 ;• : o ..-. C;?
".*• * .... ; - 7- - - . .-... .* ...-..
,,-., ~ 4.6.5.1 (Continued)
The accessory units shall be engaged with the cable assembly and tightened
to the detailed torque requirements;normal locking means without the use of
safety wire. The cable assembly shall be clamped to nonvibrating points
at least 8 inches from the rear of the connectors. ThL clampinq length
shall be chosen to avoid resonance of the wire cables.

4.6.51.1 Procedure.
The mated connector shall be mounted as specified
in 4.6.5.1 and vibrated in accno:ance with method 2005, test tinditiui. I1
of MIL-STD-1344. The contact shall be wired in series with 100 +10 milli-
amperes allowed to flow. A suitable instrument shall be employed to monitor
the current flow and to indicate discontinuity of contact or interruption
of current flow (see 3.10.1).

4.6.5.2 Temperature and humidity (see 3.10.2 and 3.0.3). Maintain


chambers used for temperature and humidity tests within plus or minus 2 C
of the specified temperature throughout the test.

4.6.5.2.1 Low-temperature storage and operation. Install a mating


plug on each end of the cable assembly that is provided with a plug.
Equip each n,+ing plug with a minimum of 3 feet of cable with bared ends.
Place the cable assemblies in a test chamber and expose to an ambient
temperature of minus 55 0 C for 24 hours. Test each assembly as specified
"in 4.6.4.2. Any defects in connectors, adapters, dummies, or plugs such
as cracks or separation of connecters from the cable shall constitute
failure of this test.

4.6.5.2.2 High-tepewrature and humidity storage and operation.


Install a mating plug on each end of each cable assembly provided with a
plug. Equip the mating plug with a minimum of 3 feet of cable. Place the
cable assemblies in the test chamber and expose to an ambient tecr'--1'-,
of plus 125 0 F. and maximum humidity for a ?eriod of 24 hours. Test each
asse-rbly as specified in 4.6.4.2. Any defects in connectors, adapters,
V dmmties or plugs such as cracks or separation of connectors from the cable
shall ccnstitute f;=1ure of this test.

87

::.L.................
.......... ... ...........
I-I

4.6.5.3 Salt atmosphere (see 3.10.4). The cable assemblies shall be


exposed to a salt-fog atmosphere for a period of 48 hours in accordance with

MIL-STD-810, method 409, procedure 1. (See 3.10.4.) The test shall be conduc-
ted at 25o +5oC.

4.6.5.4 Altitude (see 3.10.5). Install a mating plug on each end of


the cable assembly that is provided with a plug. Equip each mating plug
with a rrirmum of 3 feet of cable with bared ends. Place the cable assemblies
in the test chambe, and expose to altitude at room ambient temperature.
Mated connectors shall be tested in accordance with MIL-STD-810. The following
details shall apply:

a. The connector cable ends shall be located outside the chamber.


The cable ends may be submerged in an insulating liquid or sealed.
b. Paragraphs 4.4 and 5(e) of method 1004 shall not apply.
c. Test altitude shall be 50,000 feet unless otherwie specified.
d. After 15 minutes at altitude, the cable assembly shall be tested
for partial discharges as specified in 4.6.4.4.

4.6.5.5 Bonding (see 3.10.6). One plug of the cable assembly with
3 feet excess cable in a fully cured condition as determined by correct duro-
meter shall be tested as follows:

a. Install a dummy mating plug on a solid bulkhead.


b. Install the test plug in the mating dummy plug and tighten per
specification.
c. Bend the cable per the minimum bend radius for the cable assembly
two times in four directions at room ambient.

Any defects in the conmector, cable, or test plug such as a crack between
the connector metal and jacket shall constitute a failure of this test

88
5. PREPARATION FOR DELIVERY

5.1 Preservation, packing and packaging. Preservation, packing, and


packaging shall be in accordance with MIL-B-121. Cable assemblies shall be
packaged as complete assemblies as indicated on the applicable specification
sheet and shall be individually wrapped in a protective sheet and separated
one from the other. The supplier may use his otn commercial practice
provided it affords protection against deterioration and damage from the
supplier to the initial destination.

5.1.1 Connector protection. Each connector on a cable assembly shall be


terminated into a shorted mating cap during shipping and storage.

5.2 The subject commodity shall be packed in substantial


Packing.
commercial :ontainers of the type, size, and kind commonly used for tCe
purpose, so constructed as to insu; acceptance and safe delivery by commoa
or other carriers, at the lowest rt., to point of delivery called for in
the contract or purchase order.

5.3 Marking.

5.3.1 Exterior container. Exterior container shail be marked in


accordance with MIL-STD-129.

.4• L
ZL: .• ! ;-'-!?i, . -••• - ••?..•: -. •,•':i.• ; • ? -• "-'' > - , '- • .•;:' : ;: ••.'• -i T, .••• •i • {• i i'L- : •

989
6. NOTES

6.1 Intended use. The cable assemblies are intended for use in
airborne, high-voltage, high-power electrical power systems.

6.2 Ordering data. Procurement documents should specify the


following:

a. Title, number, and date of this criteria document.


b. Applicable specification sheet (see 3.1).
c. Level of preservation and packaging and level of packing
required (see 5.1 and 6.2).

Preproductiov. model. Any changes or deviations of production


6.3
cableassemblies from the approved preproduction models during production
will be subject to the approval of the contracting officer. Approval
of the preproduction models will not relieve the supplier of his obliga-

tion to furnish cable assemblies conforming to this specification.

90

. -- -.-, , , -. .- - - -.- a. *a.. . ". ' ....-.


-" - ... - • . "" . - . -a "a-."".a.a.--'-: '
o.1

APPENDIX C
HIGH VOLTAGE CAPACITOR CRITERIA DOCUMENT

1 91
* HIGH VOLTAGE CAPACITOR CRITERIA DOCUMENT

This specification is approved for use by all Depart-


mnsand Aencies of the Department of Defense.

1. SCOPE

1.1 Scope. This specification covers the general requirements for estab-
lished reliability (ER) and non-established reliability (non-ER), direct
cur'rent (dc), plastic or paper-plastic dielectric, high-voltage fixed capa-
* citors, hermetically sealed in metal or ceramic or glass cases. Capacitors
* meeting the established reliability requirements specified herein have fail-
* ure rate (FR) levels ranging from 2.0 percent to 0.001 percent per 1,000
hours (see 1.2.1.9). These FR levels are established at a 90-percent confi-
dence level and maintained at a 10-percent producer's risk and are based on
life tests performed at maximum rated voltage and maximum rated temperature.
An acceleration factor of 5:1 has been used to relate the life test data
obtained at 140 percent of rated dc: voltage at the applicable high test
temperature to the rated voltage at the applicable high test temperature.
This specification also covers removable mountin~g retainers for use with
* applicable capacitors (see 3.1).

* 1.2 Classification.

*1.2.1 Part number. The part number shall be in the following form, and as
specified (see 3.1 and 6.2):

CR9AM C152KI

ER Ter- Circuit Charac- Voltage Capaci- Capaci- 'Iibra- Failure


*style minal 1.2.1.3 teristic 1.2.1.5 tance tance tion rate
1.2.1.1 1.2.1.2 1.2.1.4 1.2.1.6 toler- grade level
ance 1.2.1.8 1.2.1.9
1.2.1.7

92
- --. 2
A 1 MC152 1

Non-ER Ter- Circuit Charac- Voltage Capaci- Capaci- Vibration


style minal 1.2.1.3 teristic 1.2.1.5 tance tance grade
1.2.1.1 1.2.1.2 1.2.1.4 1.2.1.6 toler- 1.2.1.8
ance
1.2.1.7

1.2.1.1 Style.The style is identified by either the five-letter symbol


"CQHVR" or the four-letter symbol "CQHV" followed by a two-digit number.
The letters identify plasti'- (or paper-plastic) dielectric, high voltage,
fixed capacitor, hermetically sealed in metal, ceramic or glass cases. The
symbol "CQHVR" identifies established reliability (ER) capacitors; the
symbol "CHQV" identifies capacitors for which no specific reliability require-
ments are specified (non-ER). The first digit following the letter symbols
identifies the general shape of the case, and the second digit identifies
specific details other than case size. Each style designation may include a
family of case sizes.
*8

1.2.1.2 Terminal. The terminal is identified by a single letter in accord-


ance with table Cl.

TABLE C1. Terminal.

Symbol Type of terminid

C Threaded stud and nuts.


D&H-...... Pillar insulator for use at altitudes up to
7,500 feet (22.8 inches of mercury).
Furnished with threaded stud and nuts.
E------- Pillar insulator for use at altitudes up to
50,000 feet (3.4 inches of mercury).
J. Busing insulator with corona protected terminal.
K High voltage connector per MIL-C-5015 (modified).

1.2.1.3 Circuit. The circuit diagram and the number of terminals are iden-
tified by a single digit in accordance with table C2.

!
s• '%. .

93
TABLE C2. Circuit diagram and number of terminals.

Symbol Circuit diagram Number of terminals

1 I 02 2
3 10 I .±. 2 3

1.2.1.4 Characteristic. The characteristic is identified by a single letter


in accordance with table C3.

TABLE C3. Characteristic.


Values for characteristics
___ 11P 111
__T IM I N SiRI -
High ambient test temperature, degrees
centigrade +30 C. / ----------------- 85 65 170 85 125 125 85 65
Low ambient test temperature, degrees
centigrade +OC. --------------------- 65 -65 -65 -65 -55 -55 -55 -30
-5
Life-test dc voltage, in percent of
the dc voltage rating (see 4.7.22):
Watt-second group (see 6.5.3):
I (0.5 watt-second and less) ---- 140 140 140 140 140 140 140
II (0.5+ to 5 watt-seconds) 140 --- 140 ---
III (5+ to 50 watt-seconds) 140 --- 140 --- 100
l------------
IV (greater than 50 watt-seconds) 140 --- 140 ---------- 100
Flashpoint of impregnant or filling
..compound, degrees centigrade -------- 142 142 217 142 142 142 135 176
I/ For characteristic K, voltage derating may be necessary at the high ambient
test temperature (see 3.1).

1.2.1.5 Voltage.The dc voltage rating for continuous operation at the high


ambient test temperature specified in table C3 (except for characteristic K
which is for 85 0 C operation), is identified by a single letter in accordance
with table C4.

94
.js •z;~ . r< C rz. ru
. '.; -•. "- .v .{. t .t•.• ,¸• .W .¸ %.t..-o .... - . . . . . . . .

TABLE C4. DC voltage rating.

Symbol DC voltage rating


KV Crest
A ----- 12.5
B 15
C ----. 25
E 50
F 75
G- 100
H 125
J 150
K ----- 175
L 200
250
N ----- 300

1.2.1.6 Capacitance. The nominal capacitance value expressed in picofarads


(pF) is identified by a three-digit number; the first two digits represent
significant figures, and the last digit specifies the number of zeris to
follow.

1.2.1.7 Capacitance tolerance. The capacitance tolerance in percent is


identified by a single letter in accordance with table C5.

TABLE C5. Capacitance toleranceJ

Symbol Capacitance tolerance


Percent (_)
F ------ 1
G ------ 2
J .5
K ------ 10

95

- - ., , - , . ," . . ' . . , . - . . - . . - _. - - . - . , -
1.2.1.8 Vibration grade. The vibration grade is identified by a single
digit in accordance with table C6.

TABLE C6. Vibration grade.

Symbol j Frequency range Acceleration


Hz G
1 ------- 10 to 55 inclusive ....
3 ------ 10 to 2,000 inclusive 15

1.2.1.9 Failure rate level. The failure level in percent per 1,000 hours
is identified by a single letter in accordance with table C7, and is based
on rated voltage at the high test temperature, as applicable.

TABLE C7. Failure rate level.

Failure rate level


L-ymbol (percent per 1,000hours)
L ------ 2.0
M ------ 1.0
P ------ 0.1
R ------ 0.01
S ------ 0.001

2. APPLICABLE DOCUMENTS

2.1 The following documents, of the issue in effect on date of invitation


for bids or request for proposal, form a part of this specification to the
extent specified herein.

SPECIFICATIONS
MILITARY
MIL-I-10 - Insulating Compound, Electrical, Ceramic, Class L.
MIL-C-39028 - Capacitors, Packaging of.

(See Supplement 1 for list of associated specification sheets.)

96
.iq

STANDARDS
MILITARY

MIL -STD- 105 Sampling Procedures and Tables for Inspection by


Attributes
MIL-STD-202 Test Methods for Electronic and Electrical Com-
ponent Parts
MiL-STD-690 - Failure Rate Sampling Plans and Procedures
MIL-STD-790 - Reliability Assurance program for Electronic
Parts Specifications
MIL-STD-810 - Environmental Test Methods
MIL-STD-1285 - Marking of Electrical and Electronic Parts

(Copies of specifications, standards, drawings, and publications required by


suppliers in connection with specific procurement functions should be obtained
from the procuring activity or as directed by the contracting officer.)

2.2 Other publications. The following documents form a part of this specifi-
cation to the extent specified herein. Unless otherwise indicated, the issue in
effect on date of invitation for bids or request for proposal shall apply.

ASTM-D 1868 - Detection and Measurement of Discharge (Corona)


Pualses in Evaluation of Insulatio i Systems.
ASTM-D 3382-75 - Measurement of Energy and Integrated Charge
Transfer Due to Partial Discharges (Corona) Using
Bridge Techniques.
ASTM-D 3426 - Dielectric Breakdown Voltage and Dielectric
Strength of Solid Electrical Insulating
Materials Using Impulse Waves.

INSTITUTE OF ELECTRICAL AND ELECTRONIC ENGINEERS


IEEE STD-4 IEEE Standard Techniques for High Voltage Testing

NEMA Publication No. 109 - IEEE-EEI-NEMA Standard Basic Insulation Level.

!
J9
NATIONAL BUREAU OF STANDARDS
"Handbook H2% - Screw-Thread Standards for Federal Services.
(Application for copies should be addressed to the Superintendent of Documents,
Government Printing Office, Washington, D.C. 20402.)

AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM)


D92-57 - Method -i. Test 2or Flash and Fire Points by Cleveland Open Cup.
(Application 1o'" .,iv,.es should be addressed to the American Society for Testing and
Materia!%, 1916 Race Street, Philadelphia, PA. 19103)

.3

*1

-,4

.3
3. REQUIREMENTS

3.1 Specification sheets. The individual item requirements shall be as


specified herein and in accordance with the applicable specification sheets.
In the event of any conflict between requirements of this specification and
the specification sheet, the latter shall govern (see 6.2).

3.2 Qualification.Capacitors and retainers furnished under this specifi-


cation shall be products which are qualified for listing on the applicable
quaiified products list at the time set for opening of bids (see 4.4 and 6.4).
In addition, -'ie manufacturer shall obtain certification from the qualifying
activity that the reliability assurance requirements of 4.1.1 have been met
and are being maintained for the ER styles. Unless procured from the manu-
facturers or his authorized distributor listed or approved for listing on
the qualified products list, ER parts furnished under this specification
shall not be considered as having met the requirements of this specification.

3.3 Reliability (applicable to ER capacitors only, see 3.1). Reliability of


"ER capacitors furnished under this specification shall be established and
* maintained in accordance with the procedures and requirements specified in
MIL-STD-790 and MIL-STD-690 with details specified in 4.1.1, 4.4.4, 4.5, and
4.6.1.3.

3.4 Material. The material shall be as specified herein; however, when a


definite material is not specified, a material shall be used which will
enable the capacitors and retainers to meet the performance requirements of
this specification. Acceptance or approval of any constituert material
shall not be construed as a guaranty of the acceptance of the finished
product.

3.4.1 Impregnant cd filling compounds. Compounds used in the impregnation


and filling of capacitors shall be chemically inactive with respect to the
capacitor element and the case (see 3.5.1). The compound, either in the
state of original application or as a result of having aged, shall have no
adverse effect on the performance of the capacitor. For liquid-filled

99
capacitors, the same material shall be used for impregnating as is used for
i! filling (see 6.3).

3.4.2 Dielectric material. Dielectric material (see 3.1) utilized in the


fabrication of capacitors shall be one of the following materials:

Characteristic Material
P ------------- Polystyrene
M------------ Polyethylene terephthalate
E& K Paper and polyethylene terephthalate
T ------------- Polytetrafluoroethylene
Q------------- Polycarbonate
S -- Polysulfone
L ------------- Polypropylene
N------------ Polymide
R------------- Polyvinyl fluoride
U------------- Polyvinylidene fluoride

3.5 Design and construction.


Capacitors and retainers shall be of the design,
construction, and physical dimensions specified (see 3.1).

3.5.1 Case. Each capacitor shall be enclosed in a hermetically-sealed metal


or ceramic or glass case (see 3.1) which will prevent leakage of the impreg-
nant or filling compound and, in addition, will protect the capacitor element
from moisture and mechanical damage under all test cnnditions specified
herein. Ceramic used for case materials shall conform to MIL-I-lO. The use
of exterior cardboard sleeves for insulating purposes shall not be permitted.

3.5.2 Noninductive construction. Unless otherwise specified (see 3.1),


tubular capacitors shall be of extended-foil construction. When tab construc-
tion is used, each pair of tabs shall be brought from opposite foils within
one turn of the foil winding from each other, unless otherwise specified
(see 3.1).

100

•'-•"' " • -.' •",'1? •: { " .' ' -. : " • .. " ' "i .. . .. " - -. - - -. -• -' . . " ' - " ". -. . " - . .-. " ." " .- " - - ". -
3.5.3 Terminals.

3.5.3.1 Case as terminal. When the case is used as a terminal, any protec-
tive coating applied to the mounting surfaces shall be such as to provide a
direct conducting path for an electric current from the case to the surface
on which it is mounted.

3.5.3.2 Corona suppressors. Corona suppressors shall be supplied when screw


terminals of paragraph 3.5.3.3 are used at rated voltages greater than l5kVDC.
The terminal and nut shall not exceed the height of the corona suppressor.

3.5.3.3 Screw terminals. Screw terminals shall be supplied with one nut,
one flat washer, and one lockwasher.

3.5.3.4 Wire leads and pins. Leads and pins shall be of copper or copper
covered steel. Copper covered steel leads and pins shall have a minimum of
30 percent of the conductivity of electrolytic copper. Leads and pins shall
be coated with solder having a tin content of 40 to 70 percent.

3.5.3.5 Terminal insulators. Terminal insulators shall be glass or ceramic.

3,5.3.6 Connectors. Connectors shall be hermetically sealed, circular


threaded, high voltage with solder or brazed contacts.

3.5.4 Threaded parts. All threaded parts shall be as specified (see 3.1),
and in accordance with H28.

3.5.4.1 Engagement of threaded parts. All threaded parts shall engage by at


least three full threads.

3.5.4.2 Locking of screw-thread assemblies. All screw-thread assemblies


shall be rendered resistant to loosening under vibration. Lockwashers shall
be provided under all nuts.

4.

101

A ,_ !N2
_0 T K .- TU -7-72

3.5.5 Safety.

3.5.5.1 Containment. Internal failure at rated voltage of one of ten parallel


equal rating capacitors shall not cause solids, liquids or gases to escape
the capacitor envelope.

3.5.5.2 Shorting. Disconnected capacitors shall not accrue terminal voltage


faster than 15 volts per hour. Except for intervals of two hours maximum,
terminals of individual and assemblies of capacitors shall be shorted with a
metallic conductor during storage, shipping and handling.

3.6 Burn-in (ERs only, when applicable, see 3.1). When capacitors are
tested as specified in 1.7.3, there shall be no evidence of damage, arcing
or breakdown.

3.7 Radiographic inspection (ERs only, when applicable, see 3.1). When capa-
citors are tested as specified in 4.7.4, X-ray examination shall disclose no
evidence of improperly made connections, misalignments of seals or eyelets,
substandard soldering or structural weakness, or solder particles or slivers
attached to one end.

3.8 Thermal shock. When tested as specified in 4.7.5, capacitors and retainers
shall withstand the extremes of high and low temperatures without visible
damage.

3.9 Seal. When capacitors are tested as specified in 4.7.6, there shall be
no continuous visible stream of bubbles or other evidence of leakage.

3.10 Dielectric withstanding voltage (DWV).

3.10.1 Capacitors. When capacitors are tested As specified in 4.7.7.1, there


shall be no momentary or intermittent arcing or other indication of breakdown,
nor shall there be any visible evidence of damage.

4. 10a
"• lo .
3.10.2 Sleeving (when applicable, see 3.1). When capacitors are tested as
specified in 4.7.7.2, the insulating sleeve shall withstand the specified
potential without breakdown.

3.11 Barometric pressure (reduced) (when applicable, see 3.1). When capa-
citors are tested as specified in 4.7.8, there shall be no momentary or inter-
mittent arcing or other indication of breakdown, nor shall there be any
visible evidence of damage.

3.12 Insulation resistance.

3.12.1 Sleeving (when applicable, see 3.1). When measured as specified in


4.7.9, the ;nsulation resistance shall be not less than 1,000 megohms.

3.12.2 Terminal to terminal. When measured as specified in 4.7.9, the


-4 insulation resistance shall be not less than the applicable values specified
(see 3.1).

3.12.3 Terminal to case. When measured as specified in 4.7.9, the insulation


resistance between any terminal and case, when the case is not a terminal,
shall exceed 50,000 megohms, unless otherwise specified (see 3.1).

3.13 Capacitance. When measured as specified in 4.7.10, the capacitance


shall be within the tolerance specified (see 3.1).

3.14 Dissipation factor. When measured as specified in 4.7.11 the dissipa-


tion factor shall not exceed the applicable value specified (see 3.1).

3.15 Vibration. When capacitors are tested as specified in 4.7.12, there


shall be no intermittent contacts or momentary arcing, or other indication of
breakdown, nor shall there be any open-or-short circuiting or evidence of
mechanical damage. In addition, retainers, as tested to 4.7.12 shall exhibit
no evidence of mechanical damage.

103
°o. . ..
3.16 Salt spray (corrosion) (metal surfaces only, see 3.1). When capacitors
or retainers are tested as specified in 4.7.13, there shall be no evidence of
harmful corrosion, and at least 90 percent of any exposed metal surfaces of
the capacitor or retainer shall be protected by the finish. For capacitor!
or retaipers with painted surfaces, not more than 10 percent of the surfaces
shall be affected by flaking, peeling, or blistering of paint. There shall
be no evidence of unwrapping of or mechanical damage to insulating sleeves.
In addition, corrosion of the terminal hardware or mounting surface shall
not exceed 10 percent of the surface area. Marking shall remain legible.

NOTE: Harmful corrosion shall be construed as any type of corrosion which


in any way interferes with the mechanical or electrical performance
of the capacitor or retainer, as applicable.

3.17 Immersion. When tested as specified in 4.7.14, capacitors or retainers,


as applicable, shall meet the following requirements:

(a) Capacitors:
Dielectric withstanding voltage:
Insulating sleeves (when applicable,
see 3.1) ------------------------- Not less than rated
voltage.
Terminal to terminal ----------------- As specified in 3.10.1.
Terminal to case -------------------- As specified in 3.10.1.
Insulation resistance at 25°c:
Insulating sleeves (when applicable,
see 3.1) ------------------------- Not less than 1,000
megohms.
Terminal to terminal ----------------- Unless otherwise speci-
fied, not less than 60
percent of the value
specified in 3.12.2.
Terminal to case -------------------- Unless otherwise speci-
fied, not less than 50
percent of the value
specified in 3.12.3.

104
?• "'• .'." •", " ." " .'"". " " .""."
." -.- .,'. - "-. ".-. . '.' " -' ." . " . ." . " '. "• -' - ." •, " " • ." . " ",
,•
,; ... r ..- -- v• s,,ci W . , -t I. .b _rS, ;t , C,- ?..U
. .,. .. C. .C k•'. . .° o - "-.= ' -. • •• • •r '•.• '°' •; '. • ° .' ° °° a

Capacitance ------------------------ Shall change not more


than +1.0 percent from

"the value obtained when


measured as specified
in 4.7.10.
Dissipation factor ------------------- Shall not exceed 120 per-
cent of the initial value
specified (see 3.1).

(b) Capacitors and retainers:


Visual examination ----------------- There shall be no harmful or
extensive corrosion of the
capacitors or retainers.
The marking shall remain
legible.

3.18 Solderability (wire leads only, see 3.1). When capacitors are tested as
specified in 4.7.15, the dipped portion of the terminals shall conform to the
solid-wire termination criteria of method 208 of MIL-STD-202.

3.19 Shock (specified pulse). When capacitors are tested as specified in


4.7.16, there shall be no intermittent contacts of 0.5 ms or greater duration,
or arcing or other indications of breakdown, nor shall there be any open or
short circuiting or evidence of mechanical damage.

3.20 Terminal strength. When capacitors are tested as specified in 4.7.17,


there shall be no mechanical damage to the capacitor or terminals.

3.21 Moisture resistance. When tested as specified in 4.7.18, capacitors or


retainers, as applicable, shall meet the following requirements:

(a) Capacitors:
Dielectric withstanding voltage:
Insulating'sleeves (when applicable,
see 3.1) ---------------------------- Not less than 4,000 Vdc.
Terminal to terminal --------------- As specified in 3.10.1.
Terminals to case (circuit diagram
1 only) ----------------------- As specified in 3.10.1.

105

S- "-.', ,-....,.".,-.,S. ,-". ' "S' '- -• - - ' •- -. .'-, -" - . . . . . "" . - ..."" ..-.-.-. -. ''"".""","'
-"""". S ."• '' 4
6 M

Insulation resistance at 250 C:


Insulating sleeves (when applicable,
see 3.1) ---------------------- Not less than 1,000
megohms.
Terminal to terminal --------------- Not less than 60 percent
of the value specified
in 3.12.2.
Terminal to case (circuit diagram
1 only) ----------------------- Not less than 50 percent
of the value speci-
fied in 3.12.3.
Capacitance ------------------------ Shall change not more than
+0.5 percent (+2.0 per-
cent from characteristic
M) from the value obtained
when measured as specified
in 4.7.10.
Dissipation factor ----------------------- Shall not exceed 120 per-
cent of the initial val-
ues specified (see 3.1).

(b) Capacitors and retainers


"Visual examination ------------------ There shall be no harmful

or extensive corrosion
of the capacitors or
retainers. The marking
shall remain legible.

3.22 Dielectric absorption (when specified, see 3.1). When measured as spec-
ified in 4.7.19, the dielectric absorption shall not exceed the value spec-
ified (see 3.1).

3.23 Stability at low and high temn)eratures. When capacitors are tested as
specified in 4.7.20, there shall be no indication of breakdown or arcing, nor
shall there be any open-or short-circuiting or any visible evidence of mech-
anical damage. The capacitance changes at the specified temperatures shall
not exceed the applicable limits specified (see 3.1) from value at 25°C.

106

5.
3.24 Temperature coefficient (characteristic P only, see 3.1). When meas-
ured as specified in 4.7.21, the-temperature coefficient shall not exceed
-120 +50 parts per million per degree Celsius (ppm/ 0 C).

3.25 Life. When tested as specified in 4.7.22, capacitors shall meet the
following requirements:
Insulation resistance at 25 0 C------------ Unless otherwise spec-
ified, not less than
60 percent of the value
specified in 3.12.1.

Capacitance ------------------------- Shall change not more


than the percent spec-
ified (see 3.1) of the
initial value obtained
when measured as spec-
ified in 4.7.10.

SDissipation factor -------------------- Unless otherwise specified,


shall not exceed the ini-
tial value specified
(see 3.1).

Visual examination -------------------- There shall be no leakage of


impregnant or filling comp-
ound or deformation of the
case either during or after
the test.

3.26 The manufacturer shall certify that all external materials are
Fungus.
fungus resistant or shall perform the test specified in 4.7.23. When capac-
itors are tested as specified in 4.7.23, examination shall disclose no evid-
ence of fungus growth on the external surface.

3.27 Resistance to tolvents. When capacitors are tested as specified in


S4.7.24, there shall be no evidence of mechanical damage and the marking shall
remain legible.

i07

.:•'- ..
.- • .. .","..,-' ..-.-...
. .- ",..". . .'. .- ". '- -"--"--"
-".-. \ -"----'\''" -- . ---- ''..'...' ."...
.-'• ::
3.28 Resistance to soldering heat (applicable to wire-lead capacitors only).
When tested as specified in 4.7.25, capacitors shall meet the following re-
quirements:

Insulation resistance at 25C)--- ---- As specified in 3.12.


Capacitance ------------------------- Change not more than 5

percent from the ini-


tial value obtained
when measured as spec-
ified in 4.7.10.

Dissipation factor -------------------- Shall not exceed initial


limit.

3.29 Flashpoint of impregnant or filling compound. When measured as spec-


ified in 4.7.26, the flashpoint of impregnant or filling compound shall be
equal to or greater than 142°C unless otherwise specified (see 3.1).

3.30 Marking.
____ H..
3.30.1 Capacitors.
Marking of capacitors shall conform to method I of MIL-
STD-1285 and shall include the part number, "JAN" brand, trademark, source
code, date code, lot symbol, capacitance (in uF), capacitance tolerance,
and rated voltage, and when applicable, failure rate level. Unless otherwise
.1: specified (see 3.1), capacitors.shall be marked as shown in the following
example:

EXAMPLE:
CQRO9AlMC152KlM - Part number.
JAN TM 12345 - "JAN" brand (ER styles only), trademark and source
code.
7i20A. 0022UF - Date code, lot symbol and capacitance.
10% 1000 VDC - Capacitance tolerance and rated voltage.

N.
3.30.2 Partial marking. For tubular capacitors with case sizes of .175 x .406,
".195 x .406 and .235 x .406, the following partial marking may be used.

TM J 09 A 1
Trademark J L Circuit diagram
(optional) Terminal
J for JAN,-- Style number
(when applicable)

MC 152 G M
Characteristic-I l iFailure rate level (when applicable)
Voltage Capacitance tolerance
Capacitance value (see 1.2.1.6)

12345 212
Source code - - E-L Date code

3.30.3 Retainers. Retainers shall be marked with the part number, trademark,
and source code. Marking shall be on the outer surface of the retainers.

3.30.4 JAN and J marking (ER styles only). The United States Government has
adopted, and is exercising legitimate control over, the certification marks
"JAN" and "J", respectively, to indicate electrical equipment, namely, resistors,
capacitors, electron tubes and the like, procured by, or manufactured for use
by, or for the Government in accordance with standard Government specifications.
- Accordingly, capacitors procured to, and meeting all of, the criteria specified
herein and in applicable specification sheets shall bear the certification mark
"JAN", except that capacitors too small to bear the certification mark "JAN"
-• shall bear the letter "J". Capacitors furnished under contracts or orders
which either permit or require deviation from the conditions or requirements
"specified herein and in applicable specification sheets shall not bear "JAN" or
"J". In the event a capacitor sample fails to meet the requirements of this
specification and applicable specification sheets, the manufacturer shall

1109
remove the "JAN" or the "J" from the sample tested and also from all capacitors
represented by the sample. The United States Government has obtained Certificate
of Registration No. 504, 860 for the certification mark "JAN".

3.30.5 Remarking when supplying to higher FR levels. A manufacturer supplying


to higher FR levels as provided by MIL-STD-690 shall not re-mark the parts unless
specifieJ in the contract or purchase order (see 6.2).

3.30.6 Non-ER marking. An ER part may be marked and furnished as a non-ER part,
if produced on the same assembly line, and provided it is subjected to and meets
all the inspection requirements of the ER part.

3.31 Workmanship. Capacitors and retainers shall be processed in such a manner


.L%
•Y as to be uniform in quality and shall be free from pits, corrosion, cracks, rougih
edges, and other defects that will affect life, serviceability, or appearance.

3.31.1 Soldering.

3.31.1.1 Flux. Flux for soldering of electrical connections shall be rosin,


rosin and alcohol, or rosin and turpentine. No acid or acid salts shall be used
in preparation for or during soldering; however, exception is permitted for
preliminary tinning of electrical connections and for tinning or soldering of
mechanical joints not used to complete electrical circuits, but in no case
shall acid salts be used where they can come in contact with insulating
material. Where acid or acid salts are used as permitted herein, they shall be
completely neutralized and removed immediately after use. All excess flux and
solder shall be removed. Where possible, electrical connections shall be
-echanically secure before soldering and electrically contiruous after soldering.

3.31.1.2 Process. There shall be no sharp points or rough surfaces resulting


from insufficient heating. The minimum necessary amount of flux and solder
shall be used for electrical connections. Any means employed to remove an
unavoidable excess of flux shall not incur the risk of loose particles of flux,

V I~
brush bristles, or other foreign material remaining in or on the capacitor, flux being
"spreadover a large area; or damage to the capacitor. Insulation material that has been
subjected to heating during the soldering operation shall be undamaged and parts fastened
thereto shall not have become loosened,

3.31.2 Riveting (retainers only). The riveting operation shall be performed carefully
to insure that the rivet is tight and satisfactorily headed.

3.32 Partial Discharges. When measured as specified in paragraph 4.7.28 the


partial discharges shall not exceed the value specified (see 3.1). This test is for
capacitors utilized in high voltage circuits.

3.33 Pulse Voltage. When measured as specified in paragraph 4.7.29 there shall be
no momentary or intermittent arcing or other indication of breakdown or flashover, nor
shall there be any visible evidenc'•- )f damage. This test is for capacitors utilized in high
voltage circuits.

*4. QUALITY ASSURANCE PROVISIONS

4.1 Responsibility for inspection. Unless otherwise specified in the contract or


purchase order, the supplier is responsible for the performance of all inspection
requirements as specified herein. Except as otherwise specifiel in the contract or order,
the supplier may use his own or any other facilities suitable for the performance of the
inspection requirements specifier' herein, unless disapproved by the Government. The
Government reserves the right to perform any of the inspections set forth in the
specification where such inspections are deemed necessary to assure that supplies and
services conform to prescribed requirements.

4.1.1 Reliability assurance program (applicable to ER parts only). A reliability


assurance program shall be established and maintained in accordance with MIL-STD-7909
with the following exceptions:
(a) Only the following of paragraph 5.2.7 (j) shall 4pply; 'the
manufacturer shall as a minimum be able to identify the time period
during which the final production operation was performed on each
iten, of product prior to final test. The date or lot code marked on
each part shall be identified to a production lot.'
(b) Paragraph 5.2.1i.3 shall not apply.

4.2 Classification of inspection. The inspections specified herein are


classified as follows:
(a) Qualification inspection (see 4.4).
(b) Retention of qualification (see 4.5).
(c) Quality conformance inspecticn (see 4.6).

4.3 Inspection conditions. Unless otherwise specified herein, all inspections


shall be performed in accordance with the test conditions specified in the
"GENERAL REQUIREMENTS" of MIL-STD-202.

4.4 Qualification inspection 1/. Qualification inspection shall be performed


at a laboratory acceptable to the Government-(see 6.4) on sample units produced .-
ý
with equipment and procedures normally used in production.

4.4.1 Sample size. The number of capacitors or retainers to be submitted for


qualification inspection shall be as specified in table C8 or C9, respectively,
or paragraph 10 of this specification.

4.4.2 Inspection routine.

4.4.2.1 Capacitor submission, Capacitors shall be subjected to the qualification


inspection specified "itable C8 in the order shown, All sample units shall
be divided as sreified iý, table C8 for groups I through VIII inclusive, and
subjected to the inspection for their particular group; for combined voltage
group su ions, each type shall be equally represented in each group.

4.4.2.2 Retairier submission. Fourteen sample retainers shall be subjected to


the examination and tests specified In table C9 in the order shown in
1/ Qualification approval will be based on the successful completion of the test 77.
specified in table V11I, and will not be withheld pending completion of the
extended-1i:e test of 4.4.4(a).
•'• 112
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C~) ~ ) '116E
paragraph 20.2. Two specimens of each type represented in a sample shall be
subjected to group I tests. Retainers shall then be subjected to the tests
of group II. During these tests, one set of each retainer type shall support
a capacitor of the same case designation with which it is normally used
(see 3.1). Tests on retainers may be run concurrently with those specified
for capacitors in 4.4.2.1. Each retainer shall be considered as a specimen
for the purpose of determining defectives.

4.4.3 Failures.
Failures in excess of those allowed in table C8 or C9, as
applicable, shell be cause for refusal to grant qualification approval.

4.4.4 Failure rate (FR) qualification (applicable to ER parts only). FR


qualification for capacitors shall be in accordance with the general and
detailed requirements of MIL-STD-690 and the following details:
(a) Procedure I - Qualification at the initial FR level. Level "M"
(1.0 percent), of FRSP-90 shall apply. Sample units shall be subjected
to the qualification inspection specified in group V, table VIII
(see 4.4.2.1). The'entire life test sample shall be continued on test
to 6,000 hours as sperified in 4.7.22.3, upon completion of the
2,000 hour qualification.
(b) Procedure II - Extension of qualification to lower FR levels. To
extend qualification to the "R" (0.01 percent), and "S" (0.001 percent)
FR levels, data from two or more styles of similar construction may
be combined.
(c) Procedure III - Maintenance of FR level qualification. Maintenanc-
period B of FRSP-10 snall apply. Regardless of the number of pro-
duction lots produced during this period, the specified number of
unit hours shall be accumulated to mai-tain qualification (see 4.6.1).

4.5 Retention of qualification. To retain qualification, the supplier shall


forward a report at 6-month intervals to the qualifying activity. The
qualifying activity shall establish the initial reporting date. The report shall
consist of:
(a) A summary of the results of the tests performed for inspection of
product for delivery (groups A and B), indicating as a minimum the
number of-lots that have passed and the number that have failed. The
results of tests vF all reworked lots shall be identified and
accounted for.

117

-: > . . . . . . . . . . . . . . . .
(b) A summary of the results of tests performed for periodic inspection
(group C), inclt{ding the number and mode of failures. The summary shall
include results of all periodic inspection tests performed and completed
during the 6-month period. If the summary of the test results
indicates nonconformance with specification requirements, and
corrective action acceptable to the qualifying activity has not been
taken, action may be taken to remove the failing product from the
qualified products list.

TABLE C9. Qualification inspection for retainers,

Number of
ERequirement Method specimens Number
Examination or test paragraph paragraph to be defecttves
inspected allowed I/

Group I
Visual and mechanical 3.1, 3.5 to 4.7.2 2 0
examination 3.5.4.2 as
applicable
and 3.30 to
3.31.2 incl.
Group II

Vibration _/ 3.15 4.7.12


Salt spray (corrosion) 3.16 4.7.13 12 1
Temperature cycling 3.8 4.7.5

1/ A specimen having one or more defects shall be considered as a single


defective.

2/ During vibration tests, one set of each retainer type shall support a
capacitor or a dummy of comparable weight and size.

118
Failure to submit the report within 30 days after the end of each 6 month period
may result in loss of qualification for the product. In addition to the periodic
submission of inspection data, the supplier shall immediately notify the
qualifying activity at any time during the 6 month period that the inspection
data indicates failure of the qualified product to meet the requirements of the
specification.

In the event that no production occurred during the reporting period, a report
shall be submitted certifying that the company still has the capabilities and
facilities necessary to produce the item. If during 3 consecutive reporting
periods there has been no production, the manufacturer may be required, at the
discretion of the qualifying activity, to submit a representative product of each
* style to testing in accordance with the qualification inspection requirements.

4.6 quality conformance inspection.

4.6.1 Inspection of product for delivery. Inspection of product for delivery


shall consist of groups A and B inspections.

4.6.1.1 Inspection lot. An inspection lot shall consist of all capacitors in

one or more styles, produced under essentially the same conditions, and offered
for inspection at one time. The sample selected from the lot shall be represent-
ative of the styles in the lot. ER parts shall be kept separate from non-ER
parts. Styles may be grouped by characteristic as follows:

Group Characteristic Style


1-- All non-ER styles may be
grouped by characteristic.

4.6.1.2 Group A inspection. Group A inspection shall consist of the examination


and tests specified in table CIO, and shall be made on the same set of sample units
in the order shown.

4.6.1.2.1 Sampling plan. Subgroup 1 tests, except as indicated in table C1O and
subgroup 2 tests, shall be performed on each ER capacitor offered for acceptance.
Such tests shall not be repeated for purposes of reinspection. Statistical

119
sampling and inspection for subgroups 1, 2, and 3 for non-ER capacitors, and
subgroup 3 for ER capacitors shall be in accordance with MIL-STD-105 for general
inspection level II. The acceptable quality level (AQL) and limiting quality
(LQ) shall be as specified in table ClO. At the option of the manufacturer,
numerically lower AQL levels may be used as long as the specified LQ is not
exceeded numerically.

4.6.1.2.2 Manufacturer's production inspection (for ER parts only). If the


manufacturer performs tests equal to or more stringent than those specified in
subgroup i, table ClO, as the final step of his production process, group A,
subgroup 1 inspection may be waived and the data resulting from the manufac-
turer's production tests may be used instead. Authority to waive the subgroup 1
inspection shall be granted by the qualifying activity only. The following
criteria shall be complied with:
(a) Tests conducted by the manufacturer during production shall be clearly
identical to or more stringent than that specified for subgroup I.
Test conditions shall be equal to or more stringent than those specified

for subgroup 1.
(b) Manufacturer subjects 100 percent of the product supplied under this
specification to his production tests.
(c) The parameters measured and the failure criteria shall be the same as,
or more stringent than, those specified herein.
(d) The lot rejection vriteria is the same as, or more stringent than, those
specified herein.
(e) The manufacturer shall make available all information concerning the
test procedures and instrumentation used in his production tests.
This data shall be provided as part of the evaluation required for
MIL-STD-790. The manufacturer shall also make available to the
Government all records of all detail test data resulting from
production tests.
(f) Once approved, the manufacturer shall not change the test procedure or
criteria without prior notification and concurrence by the qualifying
activity.

120
"" .
* .-. *,. *. .
.- -,.- ... . . . . . . . .,.••.
..-. ,. .-
,...-. . . ,-... . .-..
.•- ,.-.. ..... ,.-,.,,,,- •,-- .. .- ,.- .,-.
,.,, ..-. ,.
TABLE CIO. Grcup A Inspection

NON-ER
Examination Requirement Method Quality level
or test paragraph paragraph AQL (% defective) ?% defective)

Major Minor
SUBGROUP i
Containment 3.5.5.1 4.7.27

Burn-in 1/ - - - 3.6 4.7.3


Radiographic Not applicable
inspection 1/ - - - 3.7 4.7.4
Temperature cycling- 3.8 4.7.5
Seal --------- 3.9 4.7.6
Dielectric with-
standing voltage .65 - - -

(capacitor only) - 3.10.1 4.7.7.1


Partial discharges - 3.32 4.7.28 / 100%
Pulse voltage - - - 3.33 4.7.29 nspect

SUBGROUP 2
Insulation resist-
ance (at 25 0 C) - - 3.12 4.7.9
Capacitance 3.13 4.7.10 .65 - - -

Dissipation
factor ------- 3.14 4.7.11

SUBGROUP 3
Visual and mech-
anical examin-
ation (external):
Physcal dimen.
sions -------- 3.1,3.5 4.7.2
Marking----.. 3.30 4.7.2 .65 2.5 1.0 (AQL)
Workmanship - - - - 3.31 4.7.2 7.6 (LQ)

42

S121.
4.6.1.2.3 Rejected lots. Lots rejected by the group A inspection shall
be segregated from new lots and those lots that have passed inspection.
Lots rejected because of failures in subgroup 2 may be offered for accept- V
ance only if the manufacturer inspects all units in the lot for those
quality characteristics found defective in the sample, and after removing
all defective units found, reinspects the lot using the tightened irspection
procedure of MIL-STD-105. Resubmitted lots shall be kept separate from
new lots, and shall be clearly identified as resubmitted lots. If, during
the 100-percent inspection of subgroups 1 and 2 (ER parts only), screening
requires that over 5 percent of the capacitors be discarded, the lot shall
be rejected.

4.6.1.2.4 Disposition of sample units. Sample units which have passed all
the group A inspection may be delivered on the con~ract or order, if the lot
is accepted.

4.6.1.3 Group B inspection.

4.6.1.3.1 For ERs and non-ERs. Group B inspection shall consist of the
tests specified !n subgroups 1 and 2 of tableCll, in the order shown, and
shall be performed on sample units which have been subjected to and have
passed the applicable tests of group A inspection.

4.6.1.3.1.1 Sampling plan. The sampling plan for subgroups 1 and 2, as


applicable, shall be in accordance with MIL-STD-105 for special inspection
level S-4. (The sample size selected for these tests shall be based on the
lot size.) The AQL and LQ shall be as specified in table Cll. At the option
of the manufacturer, a numerically lower AQL may be used as long as the LQ is
not exceeded numerically.

4.6.1.3.2 For FR level L. Group B inspection shall consist of the tests


specified in table C1land shall be performed on sample units which have been
subjected to and have passed group A inspection. The lot conformance FR
procedures are as specified in procedure IV of MIL-STD-690 with the following
details and exceptions:

122

- , S•.
' .,-_ . '-."
. .- '• . - -' • : - " . .,. -' - . . . - .- .'-' , , •- •.* .. '.- " - -. . , " '. .
(a) Lot sampling - 6 sample units (minimum).
,..W, (b)
(c)
Duration of lot conformance FRonetest
Failure criteria - See 3.25,
- 240 hours.
failure allowed.

(d) Permissible combinations - See 4.6.1.1.


(e) Disposition of samples and inspection lot - Samples may be delivered
on contract or order provided they are 100-percent inspected to
verify that they meet all requirements listed in table Cll, sub-
group 2. However, a minimum of 3 sample units shall be rand-
omly selected from the sample units and subjected to the extended
life test as specified in 4.6.1.3.4. The inspection lot may be
- shipped upon successful completion of lot conformance FR test.

4.6.1.3.3 Extended life test. Sample units which have been selected for
extended life test (see 4.6.1.3.2) shall be subjected to an additional 5,760
hours of life test as specified in 4.7.22.3.2.

4.6.1.3.4 Reject lots. If an inspection lot is rejected as a result of


failure to pass group B inspection, the lot shall not be resubmitted. How-
ever, if the lot is rejected because of failure to pass the stability at
low and high temperature test of subgroup 1, the lot may Ae resubmitted pro-
vided the defective units are removed and the lot is then subjected to 100-
percent inspection for those characteristics found defective. Resubmitted
lots shall be kept separate from nev; lots, and shall be clearly identified
as resubmitted lots. Even though the lot has been rejected, those units
which were predesignated for extended life testing shall remain or be placed
on test for the full length of time.

4.6.2 Periodic inspection. Periodic inspection shall consist of group C


inspection. Except where the results of these inspections show noncompli-
ance with the applicable requirement (see 4.6.2.1.4), delivery of products.
which have passed groups A and B inspections shall not be delayed pending
results of periodic inspection.

123
.j~msh~mv~.wL~a..y~ ~ . a~cA~~n;.L.~ .-. ~ .s, 4- . C -- r. -. -.

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u w 0 -s~ a
-C im -- c u o0.0wcl
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4A 40 00 "4- o- 0 0 -0 .
.0
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j 0 E
* 4.6.2.1 Group C inspection. Group C inspection shall be performed on sample
units which have been subjected to and have passed the applicable tests (by FR
level, failure rateand non-ER styles) for group A inspection and shall consist
of the tests specified in table C12 in the order shown. Test data shall be
reviewed as part of the complete verification of qualification.

4.6.2.1.1 Sampling plan.

4.6.2.1.1.1 For all non-ER styles and FR levels. Sample units shall be
selected from the first lot and from production lots every two months
for subgroups 1,. 2, 3 and 4, and every 12 months for subgroup 5. The highest
watt-second rating in each style, characteristic, and voltage manufactured
during the specified periods shall be represented in at least the approx-
inate ratio of production. A different sample shall be selected for each
subgroup.

4.6.2.1.1.2 For FR levels. In addition to the tests specified in 4.6.2.1.1.1,


a minimum of 10 sample units from each inspection 1.4 (see 4.6.1.1) shall be
:::
•. subjected to subgroup 4 of table C12 (see 4.6.1.3.3). Allowable failures
shall be as specified in table C4, maintenance period A of MIL-STD-690.

4.6.2.1.2 Failures. If the number of failures exceeds the number allowed


in table C12, the sample shall be considered to have failed.

4.6.2.1.3 Disposition of sample units. Sample units which have been sub-
jected to group C inspection shall not be delivered on the contract or order.

4.6.2.1.4 Noncompliance (applicable to both ER and non-ER parts). If a


sample fails to pass group C inspection, the manufacturer shall take corr-
ective action on the materials or processes, or both, as warranted, and on
all units of product which can be corrected and which were manufactured
under essentially the same conditions, with essentially the same materials,
processes, etc., and which are considered subject to the same failure.
Acceptance of the product shall be discontinued until corrective action,
acceptable to the Government, has been taken. After the corrective action
has been taken, group C inspection shall be repeated on additional sample
units (all inspection, or the inspection which the original sample failed,

125
..............................................-... ... ..
CAA

-00 a)

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00

r- cr
s- cow I.U

c CL W
wi cl 4 a

d
4-)~

0 C4 d
CL v0 ..- o )L)r. oql f
EC~Ci

ol
d CL C.,)
S- CA
'.OC 4D) U) r-.
0 ; Lc.) cof
*im 0 -
w) i-l . C%I C'j

*rJ
-j
4~) C L--
0 .*
-. r' - 1- ~ -
cc)

It.1

I .5'
S.. I.
.4C u. I n "

0
. . 01 4. )

I-t
I1 I Im I I
SI
W 4- r I I I qz Ir W 4I
I
4- C o 1 (1) 1 C I1 4 I I CL >1 (U 4)
CL I0. I I 0I s-
I I I I S-I 0

I r 4.) U M = -. r I6 U)
t 2 0 1 0 1) 0 r_ IA 0j r_ M
0I Ii I)I -r r.>1 0 15
diu I I) VS) > 0 ) LI: V) I InC-
4- C
0q I 1~ I) 4-In I
.)CL ) S-- u) c a
CL 14
CL. C_" r
w w) 0 Cc L. > 1 0 ==
40 :3
04) u 0CO
4 wJ
S
IM
)4-5 o5.
I 4-
to3 tA 4J d IA
S.
) -) r- 0
w
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~
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:0'~03 V)
0I-

4.)
U)4.
4.)C--
C

0) S
U 4.)

* di In r- a In 5.. U C10 0
at the option of the Government). Groups A and B inspections may be
reinstitutea; however, final acceptance shall be withheld until the group
C reinspection has shown that the corrective action was successful. In

the event of failure after reinspection, information concerning the fail-


ure and corrective action taken shall be furnished to the qualifying act-
ivity and the contracting officer or purchaser.

4.6.3 Inspection of preparation for delevery. Sample packages and packs


shall be selelcted and inspected in accordance with MIL-C-39028, to verify
conformance with the requirements of section 5 of this specification.

4.7 Methods of examination and test.

4.7.1 Measurement conditions.

4.7.1.1 AC measurements. Alternating-current (ac) measurements shall be


made at the frequency specified. The magnitude of the ac voltage shall be
limited to 1.0 volt root mean square (rms). The maximum dc bias voltage
shall be 2.2 volts for all ac measurements of capacitors.

4.7.1.2 Reference measurements. When requirements are based on compar-


ative measurements made before and after conditioning, the ref-=nce mea-
surement shall be considered the last measurement made at 250 +50 C prior
to conditioning. Unless reference measurements have been made within 30
days prior to the beginning of conditioning, they shall be repeated.

4.7.1.3 Power supply. The power supply used for life testing shall have
a regulation of +2 percent or less of the rated voltage. The power source
employed for dc leakage current measurements shall be stabilized to at
least +100 parts per million. No voltage fluctuations shall occur during
measurements that would produce a variation in the current measurement as
read with any acceptable dc leakage current tester used to test capacitors.

4.7.2 Visual and mechanical examination. Capacitors and retainers shall


be examined to verify that the material, design, constructiýn, physical

127

• ;•? -- • --'•.•-- ---•,• •. '..'--. -...- - -.. '- .. , -.-. '.. ,-- - ., .• .-.- .- ,,.• .. .. • . -. .- ,.. ..-.. ,
dimensions, marking, and workmanship are in eccordance with the appli-
cable requirements. (See 3.1, 3.4 to 3.5.3 inclusive, and 3.30 to
3.31.1.2 inclusive.)

4.7.3 Burn-in (see 3.6) (ERs only, when applicable, see 3.1). Oap-
acitors shall be subjected to 140 percent of the dc rated voltage at
the high ambient test temperature for 48 +8 hours. During this tesc,
capacitors shall be adequately protected against temporary voltage
surges of 10 percent or more of the test voltage. After the test,
capacitors shall show no evidence of damage, arcing, or breakdown.

4.7.4 Radiographic inspection (X-ray) (see 3.7) (ERs only, when app-
licable, see 3.11. Capacitors shall be tested in accordance with
method 209 of MIL-STD-202. The following details shall apply:

(a) Radiographic quality - Sufficient definition to determine


that specimens are free from defects specified in 3.7.
(b) Image-quality indicator - A sample part of the same type as
the part being radiographed that contains either an actual
or simulated defect which is at least 10 percent smaller
than the smallest defect to be detected.
(c) Positions of specimen - Two views perpendicular to the tern-
inal axis. After first view, specimen shall be rotated
90 degrees for the second view.
(d) Evaluation of images:
(1) Special kind of viewing equipment - Magnifying glass.
(2) Magnification - lOX.
(3) Defects to be sought in specimen - As specified in 3.7.

4.7.5 Temperature cycling (see 3.8). Capacitors and retainers shall be


tested in accordance with method 107 of MIL-STD-202. The following de-
tails and exceptions shall apply:

(a) Test condition letter - Unless otherwise specified, A,


except that during step 3, capacitors shall be conditioned
at the high ambient test temperature (see 3.1).

128
(b) Measurements before and after cycling - Not applicable. I
4.7.6 Seal (see 3.9). Capacitors shall be tested in accordance with
method 112, MIL-STD-202. The following details shall apply:

(a) Test condition letter - As specified, see 3.1.


(b) Examination after test - Capacitors shaHl be visually examined
for evidence of leakage.

4.7.6.1 Seal (alternative test (see 3.9)). For capacitors with a liquid
impregnant, the following seai test may be substituted: Capacitors shall
be placed on a clean sheet of absorbent paper and exposed to the appli-
cable high ambient test temperature for a minimum of 1 hour. The capaci-
tors shall then be visually examined for evidence of leakage of imprvg-
nant or filling compounds or bubbles from the seal. Capacitors to be
subjected to the salt spray (corrosion), and immersion tests may be
excluded from the seal test until after the salt spray (corrosion), and
immersion tests are completed.

4.7.7 Dielectric withstanding voltage (see 3.10).

""4 4.7.7.1 Capacitors. Capacitors shall be tested in accordance with


method 301, MIL-STD-202. The following details and exceptions shall
apply:

(a) Magnitude of test voltage - As specified in table C13.


(b) Nature of potential - dc.
(c) Duration of application of test voltage .As specified in
table C13.
Wd) Points of application of test voltage - As specified in
table C13.
(e) Examinations after test - Capacitors shall be visually exam-
ined for evidence of breakdown, arcing, or other visible
"damage.

"129
4.7.7.2 Sleeving (see 3.10,2) (when applicable, see 3,1), With the
capacitor horizontally mounted, a single loop of No, 20 AWG wire shal) be
secured around the insulating sleeve of the capacitor so that it extends
downward from the capacitor 3 inches minimum, and the two ends of the
wire twisted in about three cross turns. A 1-pound minimum weight shall
then be suspended from the looped wire. After exposure in this position
for a minimum of 24 hours, at the maximum rated temperature +3°C, a dc
voltage of 4,000 volts minimum, shall be applied between the case and
the looped wire. The rate of voltage application shall be 500 volts per
second and the duration of application of test voltage shall be 15
seconds, minimum.

TABLE Cl:. Dielectric-withstanding-voltage test details,

Magnt- Duration
Circuit- Test tude of of applt,
diagram Test connec- test cation of
symbol Circuit diagram points tions voltage voltage
Percent
rated dc
voltage Mnutes
1 1 0-ff------0 2 Terminal 1 to 2 200 ?]
to ter-
"minal
Terminal 1 and 2 200
to case to case

3 1 -- IO-2t- 0 2 Terminal 1 to 2 or 200_/


* to ter- 1 to case
- ini nal
1/ 175 percent rated dc voltage after immersion, and moisture resistance
tests.
2/ For the 100-percent inspection specified in 4,6,1,2, the capacitors
shall be subjected, at the option of the manufacturer, to the applica-
tion of 200 percent of rated dc voltage for not less than 5 seconds,
or 160 percent for not less than 15 seconds,
* 3/ For quality conformance inspection, application of potential may be
made between each terminal individually and the case.

130
4.7.8 Barometric pressure (reduced) (see 3.11) (when applicable,
see 3.1). Capacitors shall be tested in accordance with method 105 of
MIL-STD-202. The following details and exceptions shall apply:

(a) Method of mounting - By normal mounting means.


(b) Test condition - Unless otherwise specified (see 3.1), capa-
citors shall be subjected to a pressure of 0.82 inch of mer-
cury (80,000 feet).
(c) Test during subjection to reduced pressure - Unless otherwise
specified (see 3.1), the capacitors shall not be subjected to
a dc potential at altitudes above 6,000 feet.

4.7.9 Insulation resistance (see 3.12). Capacitors shall be tested in


accordance with method 302, MIL-STD-202. The following details and
exceptions shall apply:

(a) Test potential:


(1) Insulating sleeves - When applicable (see 3.1) - Test
condition B.
(2) Terminal to terminal and terminal to case - A potential
equal to the rated dc voltage (see 3.1) or 500 Vdc, which-
ever is less.
(b) Special conditions - The time constant of the measurement cir-
cuit with the capacitor connected shall not exceed 30 seconds.
(c) Points of measurement:
(1) Insulating sleeves - The test potential shall be applied
between the case and a piece of metal foil placed around
the insulating sleeve; the metal foil shall ,be of such
dimension as to allow at least .125-inch surface exposure
"of the insulating sleeve on each end (see 3.12.1).
"(2) Terminal to terminal - Insulation resistance shall be
measured between terminals at the maximum rated tempera-
ture, +3°C, and at 250 +3°C (see 3.12.2).
"(3) Terminals to case - When the case is not a terminal, the
measurement shall be made between each terminal and the
_ ... case at 250 +30 C (see 3.12.3).
(d) Electrification time - 15 seconds.

* 131

. . . . . . .
4.7.10 Capacitance (see 3.13). Capacitors shall be tested in accordance
with method 305 of MIL-STD-202. The following details shall apply:

(a) Test frequency - 1,000 +100 Hertz (Hz) for capacitors whose nominal
capacitance does not exceed 1 pF and whose dc voltage rating does
not exceed 3,000 volts. For capacitors not within these limits,
measurements shall be made at frequency of 100 +6 Hz or corrected
thereto.
(b) Limit of accuracy - Shall be within +0.1 percent,

4.7.11 Dissipation factor (see 3.14). The dissipation factor shall be meas-
ured with an ac voltage not greater than 20 percent of the dc voitage rating,
at a frequency of 1,000 +100 Hz, for capacitors whose nominal capacitance does
*-, not exceed 1 UF and whose dc voltage rating does not exceed 3,000 volts. For
capacitors not within these limits, measurements shall be made at a frequency of
100 + 10 Hz or corrected thereto. Measurement accuracy shall be one of the
following:

(a) For dial reading - +2 percent of dial reading or .001, whichever


is greater.
(b) For digital readout - +.00l percent +2 percent of reading.

4.7.12 Vibration (see 3.15 and 3.1).

4.7.12.1 Low frequency, Capacitors shall be tested in accordance with method


201 of MIL-STD-202. The following details and exceptions shall apply:

(a) Tests and measurements prior to vibration - Not applicable.


"(b) Method of mounting - Securely fastened by normal mounting means,
except that capacitors witnout mounting retainers in sizes 1.562 inch
long or LCjlO inch in diameter or larger shall be mounted by a supple-
mental means other than the wire leads. Wire-lead capacitors shall be
secured .5 +.IL5 inch from the case. The extraneous leads beyond the
.5 inch securing point m.y be removed or supplemental support may be
added.
"(c) Duration of vibration:
For tubular styles - 4 hours (2 hours in each of 2 mutually perpendi'-
ular planes).

132

Z• -. .•• ,".•.
., ... ,-.- • ,..-
,.. .-. . .- .. . . ... ... .-. -... • - .. . .- * .- .. . . ° . . ...
For rectangular styles -6 hours (2 hours in each of 3 mutually
.:Y ~perpendicular planes).
(d) Tests and measurements during vibration - During the last 30 minutes
of vibration in each direction, a signal of 1+0.2 Kilohertz (kHz)
at a level of 1+0.5 volts shall be placed across the c3pacitor and
measured with suitable ac detecting equipment to determine open-
or short-circuits, or intermittent contacts. The accuracy of the
detecting equipment shall be sufficient to detect any interruption
with a duration of 0.5 ms or greater.
(e) Examination after vibration - Capacitors shall be visually examined
for evidence of mechanical damage.

4.7.12.2 High frequency. Capacitors and retainers shall be tested in accordance


with method 204 of MIL-STD-202. The following details and exceptions shall apply.

(a) Mounting of specimens - Capacitors shall be igidly mounted by the


body to a vibration test apparatus. Wire-lead capacitors shall be
secured .5+.125 inch from the case. The extraneous leads beyond the
.5 inch securing point may be removed or supplemental support may be
added.
(b) Electrical-load conditions - During the test, a potential of 125
percent of the dc rated voltage shall be applied between the terminals
of the capacitor.
(c) Test condition letter - B, with exception as specified (see 3.1).
(d) Measurements - During the last cycle in each direction, a signal of
1+0.2 kHz at a level of 1+0.5 volts shall be placed across the capa-
citor and measured with a suitable ac recording device (a permanent
record is not necessary for this test) to determine open- or short-
circuits, or intermittent contacts. The accuracy of the detecting
equipment shall be sufficient to detect any interruption with a
duration of 0.5 ms or greater.
S(e) Measurements and examination after vibration - After the test, with
capacitors still mounted on the vibration jig, the insulating sleeve
shall be tested for dielectric withstanding voltage, as specified in
4.7.7, with a potential of 2,000 Vdc between the case and bracket.
; Capacitors and retainers shall be visually examined for evidence
of mechanical damage.

133

• L•
•.-•(. ", - '. • ". . . " " .. .. . . . '.' '." -"-" " " - " "-• " ''' " " " ' " "" " -" -"
4.7.13 Salt spray(corrosion) (see 3.16). Capacitors and retainers
shall be tested in accordance with method 101, MIL-STD-202. The
following details and exceptions shall apply:

(a) Applicable salt solution - The salt solution concentration


shall be 5 percent.
(b) Test condition letter - B (48 hours).
(c) Examination after exposure - Capacitors and retainers shall
be visually examined for evidence of harmful corrosion,
unwrapping of or mechanical dimage to insulating sleeves
(when applicable), and obliteration of marking.

4.7.14 Immersion (see 3.17). Within 4 to 24 hours after completion


of temperature cycling, capacitors and retainers shall be tested in
accordance with method 104 of MIL-STD-202. The following details shall
apply:

(a) Test condition letter - B.


(b) Measurements after final cycle - For capacitors with insul-
ating sleeves, dielectric withstanding voltage, and insul-
ation resistance at 250C shall be measured as specified in
4.7.7 and 4.7.9, respectively. The test potential shall
be applied between the case and a piece of metal foil
placed around the insulating sleeve; the metal foil shall
be of such dimension as to allow at least .125-inch surface
exposure of the insulating sleeve on each end. In addition,
dielectric withstanding voltage and insulation resistance
at 250C of all capacitors shall be measured as specified
in 4.7.7 and 4.7.9, respectively. Capacitors and retainers
shall then be examined for harmful or extensive corrosion
and obliteration of marking.

4.7.15 Solderability (wire leads only, see 3.1) (see 3.18). Capacitors
shall be tested in accordance with method 208 of MIL-STD-202. The follow-
ing details shall apply:

134
(a) Number of terminations to be tested - Both leads of the
.,. -:, capacitor shall be subjected to the solderablilty test.
.. '-(b) Depth of immersion in flux and solder - The leads shall be
immersed to within .125 inrP )f the capacitor body.

4.7.16 Shock (specified pulse) (see 3.19). Capacitors and retainers


shall be tested in accordance with method 213 of MIL-STD-202. The
following details shall apply:

(a) Mounting - The body of the capacitor shall be securely


fastened by mounting retainers. The leads shall be sold-
ered to rigidly supported terminals so spaced that the
length of each lead from the capacitor shall be 1/2 + 1/8
inch from the edge of the supporting terminal.
(b) Test condition letter - I (100 G).
(c) Electrical loading during shock - During the test, a
potential of 125 percent of the dc voltage rating shall be
applied between the terminals of the capacitor.
(d) Measurements during shock - During the test, observations
shall be made to determine intermittent contact or arc-
ing or open- or short-circuiting. Detecting equipment shall
be sufficiently sensitive to detect any interruption with
a duration of 0.5 ms or greater.
(e) Examinations after test - Capacitors shall be visually
examined for evidence of breaking, arcing, fractures, or
any other visible mechanical damage. Retainers shall be
visually examined for mechanical damage.

4.7.17 Terminal strength (see 3.20). Capacitors shall be tested in


accordance with method 211 of MIL-STD-202. The following details and
exceptions shall apply:

(a) Test condition letter - As specified (see 3.1).


(b) Examination after test - The capacitors and terminals shall
"be examined for mechanical damage.
':j

135
!V
4.7.18 Moisture resistance (see 3.21). Capacitors -nd retainers shall
be tested in accordance with method 102, test condition D, MIL-STD-202,
except that no measurement shall be made before and after cycling.
Capacitors shall then be tested in accordance with method 106, MIL-STD-
202. The following details and exceptions shall apply:

(a) Initial measurements - Not applicable.


(b) Polarization voltage - During steps 1 to 6, inclusive, a dc
potential of 100 volts shall be applied across the term-
inals of 50 percent of the capacitors. No potential shall
be applied to the remaining 50 percent of the capacitors.
(c) Loading voltage - Not applicable.
(d) Final measurements - After the final cycle, the capacitors
shall be conditioned at 250 +50 C and a relative humidity of
50 +5 percent for a period of at least 22 hours but not
more than 24 hours. Dielectric withstanding voltage and
insulation resistance at 25°C shall be measured on insul-
ating sleeves as specified in 4.7.7 and 4.7.9, respectively.
The test potential shall be applied between the case and a
piece of metal foil placed around the insulating sleeve.
The metal foil shall be of such dimension as to allow at
least .125-inch surface exposure of the insulating sleeve
on each end. In addition, dielectric withstanding voltage,
insulation resistance, capacitance, and.dissipation factor
at 250 C, of all capacitors shall be measured as specified
in 4.7.7, 4.7.9, 4.7.10, and 4.7.11, respectively.

After the test, capacitors and retainers shall be visually examined for
evidence of harmful corrosion and obliteration 'of marking: capacitors
shall be examined for unwrapping of or mechanical aamage to insulated
sleeves, when applicable.

4.7.19 Dielectric absorption (see 3.22) (when specified, see 3.1).


The capacitor shall be charged at the dc voltage rating for 1 hour +1
minute. The initial surge current shall not exceed 50 milliamperes.
At the end of this period, the capacitor shall be disconnected from the
power source and discharged through a 5 ohm ± 2 percent resistor for 10
+1 seconds. The disch;arge resistor shall be disconnected from the
136

•"° *% '%% ;; ° - --% " " " " " . " . '. " " " . *' ° . ' ". " " " " . . " """ " ° • • , , °..
capacitor (recovery voltage) shall be measured with an electrometer or
.::~.- other suitable device having an input resistance of 10,000 megohms or
greater. Recovery voltage shall be read at the maximum voltage within
a 15-minute period. The dielectric absorption shall be computed from
the following formula:
V1
" x 100
d
V2

Where:
d = Percent dielectric
absorption.
V1 = Maximum recovery voltage.
V2 = Charging voltage.
For an alternate production test method see figure Cl.

4.7.20 Stability at low and high temperatures (see 3.23). Capacitors


... ~+00 0
shall be placed in a chamber mzintained at -650 .. C or -550 5o C (as
applicable, see 3.1), and a potential equal to the dc rated voltage shall
be applied at this condition for 48 +4 hours. The air within the con-
ditioning chamber shall be circulated. Before capacitors are removed from
the conditioning chamber, capacitance shall be measured at the applicable
low temperature (see 3.1) as specified in 4.7.9. Capacitance shall then
be measured at the following temperatures as specified in 4.7.9 (the
measurement at each temperature shall be recorded when o successive
readings taken at 5-minute intervals indicate no change in capacitance):

1) 250 +50 C
2) High ambient test temperature (see Table C3)
3) 250 +50

After the test, capacitors shall be visually examined for evidence of


breakdown, arcing, open- and short-circuiting, and other visible
mechanical damage.

137
~ * ~ ¶. ~ . ' ** - . * . ~ . .~

V,
3

ER2 R3 R4

FIGURE C1. Typical production dielectric absorption test method.

E =dc rated dc voltage or 100 volts dc, whichever is less (+i%).

R, and R2 = 1000 Ohms +.20% (This value not critical.)

R3 =5 Ohms +_1%.

-.,,.'.;.,..,.,.',::,r.'.•.-,.-,•.
.- ,,.,", ,,•,.- ,=,... "•'" "" ; . ... """"'- "" " """" " .. ." " " ".. ... " '%"".".".".I
R4 10,000 Megohms - Minimum

Suggest use of +_1230A GR electrometer or equivalent set to 10,000


Megohms range input resistance.

NOTES:
1. Charge for 5 minutes + 10 seconds with switch in position 1.
2. Switch in position 2 for 5 seconds + 0.5 seconds.
3. Switch in position 3 for I minute.
4. After I minute read recovery voltage and compute as a percentage
of charge voltage.
5. Switch to position 4, discharge and remove. "-

138
4.7.21 Temperature coefficient (see 3.24) (characteristic P only, see
(. 3.1). Capacitance measurements shall be made after the capacitors
have been stabilized at each of the following temperatures: -65 0 C, +250 C,
and the high ambient test temperature (see 3.1). Stability shall be indi-
cated when no change exists in two capacitance measurements made at 5-min-
ute intervals. Temperature coeffidtent shall be computed from the following
formula: (C2 - C1 ) 106
TC = -I
(T2 - TO) C1

Where:
TC = temperature coefficient in ppm/°C.
C:= capacitance at 250 C in pF.
C2 = capacitance at test temperature in pF.
TI = 25 C.
T = test temperature in degrees C.

4.7.22 Life (see 3.25).

., *,:L''4.7.22.1 2,000-hour (qualification inspection). Capacitors shall be


tested in accordance with method 108 of MIL-STD-202. The following details
and exceptions shall apply:

(a) Distance of temperature measurements from specimens, inches -

Not applicable.
(b) Test temperature and tolerance - At the applicable high-test
+40.
temperature, C (see 3.1).
-00
(c) Operating conditions - Capacitors shall be subjected to 140
percent of the rated dc voltage. When necessary, a suitable
current-limiting resistor shall be used.
(d) Test conditton letter - F (see table C15).
(e) Measurements during and after exposure - At the conclusion of
the test, the capacitors shall be returned to the inspection
conditions specified in 4.3 and shall be visually examined
for evidence of mechanical damage and obliteration of marking;
insulation resistance at +25 0 C, capacitance, and dissipation
- factor shall be measured as specified in 4.7.9, 4.7.10, and
4.7.11, respectively.

139

At -
TABLE C15. Life test in hours.

NON-ER capacitors

Characteristic Qualification Group B Group C

E, F, or K +48 240
240 +48 -0-

-0 -0
K Mr +48
2,00 +72
+72 I-4 +48
240 +48
-0 1,6+7 -
M 2,000 240 1,760

+48+4
24 -0 240 ---
-0
Q+40
Q 2 +48
0 -0
24C +480 --

4.7.22.2 Hours (quality conformance inspection).

4.7.22.2.1 240-hour (group B inspection) (see 3.L5). Capacitors st •°


tested as specified in 4.7.22.1, except the duration of the test shall .
240 + hours.

4.7.22.2.2 2,000-hour (group C inspection) (see 3.25). Except as spec-


ified in -he following, capacitors shall be tested as specified in 4.7.22.1:

(a) Test duration - See table C15.


(b) Measuremen'ts during and after exposure - Measurements, as
specified in 4.7.22.1 (e), shall be taken at the following
+48
intervals of exposure: During the first hour, 240 -0+
+48 +72
1,000 + and 2,000 -0"

4.7.22.3 Extended life (see 3.25).

4.7.22.3.1 Following 2,000-hour qualification insnection. Sample units


that have been subjected to 2,000 hours of life test as specified in 4.7.22.1
and 4.7.22.2.2, shall remain on test for an additionai 4,000 +7 hours.
After completion of the 6,000-hour life test time, capacitors shall be
measured as specified in 4.7.22.1(e).
140

•,• •, • ." .. • o~w• .-.. ° •- . °.... °° o°,• .,° • ..° °, .


...... •, ° o ,
4.7.22.3.2 Following 240-hour group B inspection (ERparts only) (see
table C15). Sample units that have been subjected to 240 hours of life
test as specified in 4.7.22.2.1, shall remain on test for an additional
5,760 hours. Measurements, as specified in 4.7.22.1(e), shall be taken at
the following intervals of exposure: After 240 +4 , 1,000 +4 , 2,000 +7'
4,000 -0, and 6,000 +72 hours.
0-0
4.7.22.3.3 Following 240-hour yroup B inspection (non-ER parts, charact-
eristic M only, see table C15). Every 3 months, 12 sample units that have
successfully completed the 240-hour group B life test, shall be continued
on test for an additional 1,760 +7^ hours.

4.7.23 Fungus (see 3.26). Capacitors shall be tested in accordance with


method 508 of MIL-STD-810. Pretest and post-test measurements are not
required.

4.7.24 Resistance to solvents (see 3.27). Capacitors shall b '.; in


accordance with method 215 of MIL-STD-202. The following deta --.1
apply:

(a) Portion of specimen to be brushed - That portion on which


marking is present.
(b) Number of specimens to be tested - As specified in applicable
inspection tables.
(c) Permissible extent of damage - As specified in 3.27.

4.7.25 Resistance to soldering heat (see 3.28) (applicable to wire-lead


capacitors only). Capacitors shall be tested in accordance with method
210 of MIL-STD-202. The following details shall apply:

(a) Depth of immersion in the molten solder - To a minimum of 0.250


inch from the capacitor body.
(b) Test condition letter - B (2600 +50 C; 10 +1 seconds).
(c) Cooling time prior to measurement after test - 10 +1 minutes.

S4.7.26 Flashpoint of impregnant or filling compound (see 3.29). The flash-

point of impregnant or filling compound shall be measured as specified in

141
ASTM D92-57, except that the fire point and precision do not apply. "Impregnant
or filling compound" shall be substituted for the word "oil" throughout the test
method.

4.7.27 Containment. With ten identical characteristic N capacitors con-


nected in parallel, increase the dc terminal voltage until one of the paralleled
capacitors fails internally. The number of paralleled capacitors may be reduced
as the voltage is increased provided the energy stored in the remaining paral-
leled capacitors is at least as much as that for the ten paralleled capacitors at
rated voltage. Performance of the failed capacitor shall be per 3.5.5. 1. The
other capacitors in parallel with the failed capacitor shall not be damaged.

4.7.28 Partial discharges (see 3.32). Capacitors shall be tested in


accordance with ASTM D1868, (Circuit, Figure 1). The detector used shall have a
sensitivity of less than 1.0 picocoulomb before It is loaded with the test
specimen. The detector shall have a uniform frequency response up to 500
kiloherz. A liquid or gas filled unit may be tested at any angle of inclination
unless an angle is specified (see 3.1 and 6.1.2). The following details shall
apply:

a. MaCnitude of test vo.*tage - 100%;


b. Nature of potential-dc.
c. Duration of application of test voltage-partial discharges shall be
measured for 3 minutes after operating voltage is attained. Voltage
shall be increased from 0 to operating test voltage at rate of 500
volts per second.
d. Points of application of test voltage-as specified in Table C-13.
e. Examination after test-capacitors shall be visibly examined for evi-
dence of breakdown, arcing, or other visible damage.
f. Partial discharges shall not exceed the following limits.

Voltage limit Counts/Minute Not to exceed


kV PC/kV over limit PC/kV
DC 1 1 2
4.7.29 Pulso voltage (see 3.33). Capacitors shall be tested with a basic insulation
level (BIL) pulse voltage according to the IEEE-EEI-NEMA Standard

142
Basic Insulation Levels, NEMA Publication No. 109, dated January 1941 to the
value shown in Table C16. The BIL shell be in accordance with the following
definition:

"Basic insulation levels are reference levels expressed as pulse crest


voltage with a sLandard wave not longer than 1.2 x 50 microseconds (1.2
microseconds rise and 50 microseconds decay, Figure C2). Apparatus in:..ula-
tion as demonstrated by suitable tests shall have capability equal to, or
greater than, the basic insulation level."

The BIL levels upon which the capacitors shall be tested are given in Table C16.

TABLE C16: Pulse Test Voltages.

Voltage Pulse
Rating, Withstand
KV Crest Voltage (Crest)

12.5 22
S15 26
-' 25 44
•}50 88
75 130

100 175
125 220
150 260
175 305
200 350
250 440
300 525

14
.. o.

14.3
4 . . . . . . . . . . .
- --,-,. -- -. ',.. .. ,...4.,. -... ,..- ...-..
....... ..,.-.. ,..- ,.. .. ,. ... ,,...-.,.-,.,.,- ,... ,....., -.....- ... , , .
S~1.0
,; . 0. 9
Normalized I
Test 0.5
Voltase
Vol

0 1.2 50
Tume - microseconds

Figure C2: Pulse Test Voltage Profile

5.0 PREPARATION FOR DELIVERY

5.1 Capacitors shall be prepared for delivery in accordance with


MIL-C-39028. In addition to any special marking required by MIL-C-3D028 or the
contract or purchase order (see 6.2), each unit package shall be marked as
specified in MIL-STD-1285.

6.0 NOTES

6.1 Intended use.

6.1.1 ajoýtyrene dielectric capacitors. Capacitors of polystyrenz die-


lectric, because of their low dielectric absorption and radio frequency losses,
are intended primarily for use in calculators, computers, integrators, timebase
oscillators, laboratory standards, and other pulse applications. The out-
standing characteristics of these capacitors are low temperature coefficient and
stability.

6.1.2 Polyethylene terephthalate dielectric capacitors. Capacitors of


polyethylene terephthalate dielectric are intended for use in high temperature
applications similar to those served by hermetically sealed paper capacitors,
but where hlgner insulation resistance at the upper temperature limits is
required.

144

,... . . . .. ... . . .
.- -- ----- ,-----

6.1.3 Paper and polyethylene terephthalate dielectric capacitors, Capacitors


of paper and polyethylene terephthalate dielectric are intended for
" applications where small case sizes and high temperature operation are re-
quired.

6.1.4 Polytetrafluoroethylene dielectric capacitors. Capacitors of poly-


tetrafluoroethylene dielectric are intended for high temperature applications
where high insulation resistance, small capacitance change, and low
dielectric absorption are required. These capacitors exhibit excellent
insulation resistance values at high temperatures.

6.1.5 Polycarbonate dielectric capacitors. Capacitors of polycarbonate


dielectric are especially suitable for use in tuned circuits and precision
timing due to their capacitance stability and minimum capacitance change
m with temperature.

6.2 Ordering data. Procurement documents snould specify the following:

(a) Title, number, and date of this specification.


(b) Title, number, and date of the applicable specification sheet
and the complete part number (see 1.2. and 3.1).
(c) Whether removable mounting retainers are to be supplied with
capacitors (see 3.1).
(d) If remarking of parts is required to indicate FR level (see
3.30.5).
S(e) Special marking, if required (see 5.1).

6.3 Definitions.

6.3.1 Liquid-impregnated capacitor. A liquid-impregnated capacitor is a


capacitor in which a liquid impregnant is dominantly contained within the
capacitor element, but does not occupy substantially all of the case volume
not required by the capacitor element and its connection.

14
145

. . ..`.....-....... ..
-..... .. `...... . . .`.`
`..`...-... ... .. -.. ` ... ` ... -.. ''.,,'' ,. " ". .. ' . " ' , '.' .
6.3.2 Liquid-filled capacitor. A liquiid-filled capacitor is a capacitor in
which a liquid impree~r-nt ac)ci•ies ,ub-tantially all of the case volume not
required by tVe capacitor e'l,..2nt and its connections. Space may be allowed for
the expars~of of the liquid with temperature variations.

6.3.3 Nonmagnetic case capacitor. A nonmagnetic case capacitor is a capacitor


in which no part of the case or retainer is made of magnetizable material;
however, the end seal may be made of a material having a ferrous metal content
in order to effect a glass-to-metal seal.

6.3.4 Hermetic seal.For the purpose of this specification, a hermetically


sealed capacitor is one in which the capacitive element is contained within a
sealed enclosure of caramic, glass or metal, or combinations thereof, where
sealing is accomplished by material fusion, welding, brazing or soldering. The
capacitor shall be capable of passing the seal test specified in 4.37.6 or of
meeting a leak-rate requirement of not more than 1.76 x 10-6 cubic centimeters
3 ) per second, when determined by any other method having sensitivity equal
"(cm
to or better than the stated limit. When capacitors are tested as specified in
4.7.6, there shall be no continuous visible stream of bubbles.

6.4 qualification. 2/ With respect to products requiring qualification, awards


will be made only for products which are at the time set for opening of bids
qualified for inclusion in the applicable qualified products list whether or not
such products have actually been so listed by that date. The attention of the
suppliers is called to this requirement, and manufacturers are urged to arrange
to have the prodicts that they propose to offer to the Federal Government tested
for qualification in order that they may be eligible to be awarded contracts or
orders for the products covered by this specification. The activity responsible

2/ SD-6, "Provisions Governing Qualification," is issued for the information of


applicants requesting qualification of product. Copies of this publication may
be obtained from the Commanding Officer, Naval Publications and Forms Center,
5801 Tabor Avenue, Philadelphia, PA 19120.

146

-•~~~~~.-..,-,-.
...-.- •-.,, , . ,.. . :...-.....-...-...-...
..-................ ... ., °....
for the qualified products list is the Air Force, Code 80, FSG 59, Directorate
0of Engineering and Technical Support Branch, SMAMA (MMRE), Wright-Patterson AFB,
Ohio 45433. However, information pertaining to qualification of products may be
obtained from the Defense Electronics Supply Center (DESC-EQ), 1507 Wilmington
Pike, Dayton, Ohio 45444.

6.5 Application information.

6.5.1 Mounting. Capacitors covered by this specification shall be mounted by


a retainer or clamp or should be potted when vibration or shock are likely to
be encountered in service.

6.5.2 Voltage derating with temperature (for characteristic M). Characteristic


M tubular capacitors may be used in applications up to 1250C with voltage
derating as indicated in figure C3. However, insulation resistance requirements
at 1250C cannot be expected to exceed 100 megohms; greater capacitance change
may be encountered, and life expectancy of the unit will be reduced.

100
95
90
85
VOLTAGE
DERATING 75
(%) 70
65
60
55
50 1
85 90 95 10n105 110115 20125
OPERATING TEMPERATURE (OC)

Figure C3. Intended operating temperature.

147
.
6.5.3 Energy content (in watt-seconds). The energy content of a fully charged
dc capacitor is determined by the following formula: V-,

2
wCE
Where:

W = energy content in watt-seconds.


C = nominal capacitance in farads.
E = dc voltage rating in volts.

6.5.4 AC component. The rating given is the steady-state dc voltage, or the sum
of the dc voltage and the peak ac voltage, provided that the peak ac voltage does
not exceed 20 percent of the rating at 60 Hz, 15 percent at 120 Hz, or 1 percent
at 10,000 Hz. Where heavy transient or pulse currents are encountered, the
requirements of this specification are not sufficient to guarantee satisfactory
performance, and due allowance must therefore be made in the selection of a
capacitor.

6.5.5 Barometric pressure (reduced) (see 4.7.8).

6.5.5.1 Ceramic.. or glass-cased tubular capacitors. The dc voltage that may be


applied to ceramic- or glass-cased tubular capacitors at altitudes from 50,000 to
100,000 feet may be obtained from figure C4. The voltage shall be limited to
1000 VDC unless otherwise specifed.

3.0 -
Ii
z 2.0

T I%,

1000 1500 2000 3000 4000 5000 6000 8000

OPERATiNG VOLTAGE DC

Figure C4. Permissible operating voltage at ltitudes from 50,000 to 100,000 feet.

*477

148

•.. % "... .. •..%•..•


. % .. ". •. . •. %° -......... - . . .•. . . . . , . . .- N%.. • ., -
6.5.5.2 Metal-cased tubular capacitors, The dc voltage that may be applied to
metal-cased tubular capacitors at altitudes other than 80,000 feet may be obtained
from figure C5,except that the dc voltage rating must not be exceeded.

6.5.6 Representation of minimum insulation-resistance requirements. A graphical


representation of minimum insulation-resistance requirements, as specified in the
applicable specification sheet, is shown in figure C6.

6.5.7 Life at temperatures and voltages below and above rated. The failure rates
used in this specification are referred to operation at rated voltage at the
maximum rated temperature. The sampling plans and failure-rate determinations
throughout the specification assume an acceleration factor of 5 for the life test
conducted at the maximum rated temperature and 140 percent of rated voltage.
Lower failure rates than those for which the manufacturer has obtained qualifi-
cation may be achieved by operating the capacitors at lower voltage, or at lower
temperatures, or both. Factors by which failure rates are to be multiplied under
conditions other than maximum conditions are shown on figure C7(characteristic
K only).

6.5.8 Temperature rise. Minimum insulation resistance of characteristic N


capacitors shall be great enough to cause temperature rise to 50F maximum when
the capacitor is operated at rated voltage in a 50,000 ft pressure altitude,
rated temperature environment.

6.6 Selection and use information.


Equipment designers should refer to MIL-
STD-198, "Capacitors, selection and use of", for standard capacitor types and
selected values chosen from this specification. MIL-STD-198 provides a selection
of standard capacitors for new equipment design.

149
.. ... '-.-'-
• -,'-'•'-'.. .. .....' .- .'.-.-" .'-." "."~.- ."
* ." -•. . .
.. .. .. .

6TIU4L

-
Ir

7...

'-Ilk

150
I

oi IR
III C.T'I

5 e#
I i H*.r mA s

10000

HilI CAPAC11
ITANC INU
1000AT16

CHSST8 I H

1~ ~~~~~. FATir C6 rhc srenalno MnmmIwaln-RaCw


Req,.netzbyDIt, ~~cf~ I te ppUNl
CIecif0 cTt1'2Sheet

Ul 1.151
.4HS EA

if I I I Ijl ,il l

11 1 1 11 Hi " & . "'.. S


A e
-- S1111.1 1* 1 1 lilt

c_ 100
*ý- P-

m-' n

-99

01 1 1 - 'r IL

.944

j..3

4)w

~..2
.00

.9.03

.901

NOTE. CURVES FOR 100 PERCENT OF RATED VOLTAGE AND HIGHER ARE BASED ON
THE STH POWER RULE AND CURVES FOR 00 PE RCENT OF RATED VOLTAGE
AND BELOW ARE EASED ON THE 4TH POWER RULE.

Figure C7?: Life at Temperature end Voltage Relativ to Percet Rating


(0rwaeW*t K Only)

15?
" "- ....... sjrw.... ,,w•,• n• srrt-,, • n r. -s --.
l . W,WY
.2.I .o i.2. ,- •..& . -. , 3M. , p ,,- , Lr.*•o . ,~ Lw, N - . °.'~io • .

6.7 Interchangeability and substitutability.


Whenever possible, items covered
by this specification shall be used to replace items covered by MIL-C-14157,
"Capacitors, fixed, paper (paper-plastic) or plastic dielectric, direct current
(hermetically sealed in metal cases) established reliability, general specifi-
cation for" and MIL-C-25, "Capacitors, fixed, paper-dielectric, direct current
(hermetically sealed in metal case) general specification for."

6.8 Changes from previous issue. Asterisks are not used in this revision to
identify changis with respect to the previous issue, due to the extensiveness
of the changes.

153

•-*.. .. .. . . * "1"* .
."-° A a... " " -, " ' '•" " , " ' " "-.'° " "... . "." ". . "I . -.-"°*. • ,, -°. , ° , ' .
S,8

10. PROCEDURE FOR QUALIFICATION INSPECTION

'.-g1 10.1 This details the procedure for submission of samples, with related
data, for qualification inspection of capacitors and retainers covered by this
specification. The procedure for extending qualification of the required sample
to other capacitors and retainers covered by this specifi--ation is also outlined
herein.

20. SUBMISSION

20.1 Single-type capacitor submission. The following details apply:

(a) Sample size - As specified in table C8.


(b) Sampling criteria - Sample units of the same style, terminal, circuit,
characteristic, rated voltage, capacitance, capacitance tolerance, and
vibration grade will be submitted.
(c) Extent of qualification:
(1) Circuit diagram 1 will "ualify circuit diagram 3 in the same
capacitor design.
(2) Qualification in one characteristic does not constitute qualifi-
cation in any other characteristic.
(3) Capacitance tolerance, F (Table C5), may represent all other
authorized capacitance tolerances.
(4) Vibration grade 3 will qualify vibration grade 1 provided that the
designs of the capacitors are the same.
(5) Qualificatin of insulated styles will be the basis for qualifi-
cation of uninsulated styles of the same design.
(6) Qualification of ER styles will qualify applicable non-ER styles
of the same characteristic, voltage rating, and case size.
(7) Qualification approval granted for one of the lower failure rate
m
J levels will include qualification approval for all of the higher
failure rate levels.

154
i.,,-:.,.• . p,,.•.• . .,.., -..t. -,"".""••,
..-.o. -... . ""- '- . """- ." "". ""." .• ."..-2T:i.?~
." :•,-" ,- • "' •",--•,;-, l.2"T-" T "2i;..
20.1.1 Single type retainer submission. The following details apply:
(a) Sample size - As specified in table C9.
(b) Sampling critera - Sample units of the same retainer designator, design
and case size will be submitted.
(c) Extent of qualification - Qualification will be limited to the part
number submitted.

20.2 Combined type retainer submission. The following details apply:


(a) Sample size - Six retainers shall be submitted.
(b) Sampling criteria - Retainers submitted may be divided between the
largest and smallest sizes in the footed and spaded design as shown
in table C9 or in the designs in the largest and smallest case size
required for complete qualification.
(c) Extent of qualification - Either submission of (b) above will confer
eligibility for complete qualification of brackets.

20.3 Impregnant or filling compound. A minimum of 1/4 pound of each impregnant


or filling compound used in the sample units for which qualification is sought
shall be submitted.

30. DATA REQUIREMENTS

30.1 Test data. When examinations and tests are to be performed at a Government
laboratory, prior to submission, all sample units shall be subjected to all of
the examinations and tests indicated as nondestructive in table C8. Each
submission shall be accompanied by the test data obtained from these examinations
and tests. The performance of the destructive examinations and tests by the
supplier on a duplicate set of sample units is encouraged, although not required.
All test data shall be submitted in duplicate.

155

................................ .. .. .. .. ... .
• *1• • :, ,• • , , ~ .• , .• -,.•. -.• - . - . - ~ -. i.• -. . *•
o -. . -• • - - -: -. - • J. •- °'.. - b , -°

30.2 Description of items. The supplier shall submit a detailed description of

the materials and constructional features of the capacitors being submitted for
inspection, including information as to whether they are liquid impreg.'4ated or
liquid filled; the type and quantity of the impregnant or filling compli.nd;
the type, thickness, and number of layers of capacitor dielectric material and
foil; the material, thickness, and applied finish of the case; and details on
the end seal and terminal assembly.

30.3 Certification of materials. The supplier shall submit certification, in


duplicate, that the materials used in his components are in accordance with the
applicable specification requirements.

156
. . . . .
,t.0

40 CAPACITORS HIGH VOLTAGE, FIXED,


SEALED IN METAL PLASTIC (OR PAPER-PLASTIC)
CASES, STYLE CQ72 DIELECTRIC

This specification is approved for use by all Departments


and Agencizs of the Department of Defense.
40.1Scp
The complete requirements for procuring the capacitors described herein shall
consist of this document and the latest issue of Specification MIL-C-19978.

I Symbol Type of terminal


D Pillar insulator (fcr use at altitudes
up to 7,500 feet)
E Pillar insulator (for use at altitudes
up to 50,000 feet)
J Bushing insulator with corona
protected terminal
K High voltage connector per MIL-C-5015
(modified)

Terminal dimension
Terminal Terminal
number symbols V, max Y, min I Y, max Z

1 .75 .812

'I

157

'•- ' '-.- *-,.- ,-.-.. . ... . .. - - .


.~*5**
S 5 . - .. . - S~S
40.2 REQUIREMENTS:

40.2.1 Design and construction:


Dimensions and copfiguration - See figure C8 and table C19.
Construction - Extended foil or laid-in tab.
Case and ,:etainer material - Metal, nonmagnetic or magnetic.
Dielectric material - Paper and polyethylene terephthalate.
Terminals - See figures C8 and C9.
Circuit diagram -

0--1- 0

Rated voltage - See table C18.


Rated temperature - -65P to +850 C (E)
-650 to +125 0 C (K)
-550 to +850 C (F and G).
Capacitance (cap.) (non) - See table C18.
Capacitance tolerance - (±10 percent).
Vibrotion grade - See table C18.
Dissipation factor (DF) (max) - 1.0 percent.

40.2.2 Seal: Method 112 of MIL-STD-202, test condition letter - A, or in accordance


MIL-C-19978 (alternative test).

40.2.3 Barometric pressure: In accordance with MIL-C-19978; terminal D capacitors


not applicable.
Test condition letter - B (3.44 inches of mercury - 50,000 feet).
Test pjints - Between ungrounded terminal and case.
Test potential - 125 percent of dc rated voltage.
40.2.4 Insulatin resistance (IR):
Terminal to terminal - See table Ce7.
Terminals to case - Greater than 10,000 megohms.

40.2.5 Vibration, high frequency: Method 204 of MIL-STD-202, test condition B, with
the following exception:
Direction and duration of motion - 4 hours in each of two mutually
perpendicular directions (total of 8 hours), one parallel and the
other perpendicular to the cylindrical axis.

0.2.6 Salt spray: In accordance with MIL-C-19978.


.. 7 Solderability: Not applicable.
-.u.2.8 Terminal strength: Method 211 of MIL-STD-202, test condition letters -
A and E.

158

,' '. .. .. '•''. -. • •'•- .- .. * *-


. *'T- .- .-.- -.. * - . - -
wk ~~1'

•-r-°

FigureC8: Style Catorms

LL

%.

* Figure C9. Styl Oe pcitors

.' .,..9* *i5 .5 . .. 5. 159


* .* .5 ~5 . .. .5. 5 .. .5.
5.5 ..
.5 5 5 . ..5 . . .5 .5 5 . .5 5 .. 5. .5
40.2.9 Stability at low and high temperatures:
Low temperature: +00
Testotemperature - -550 +50C (F and G) or -650 -5C_(E and K).

Capacitance change (max) - (-10 percent).


High temperature:
Test temperature - +85 0 C (E, F, and G) or +125 0 C (K).
Capacitance change (max) - (+10 percent).

40.2.10 Life:
Capacitance change (max) - (+5 percent).
Resistance to soldering heat: Not applicable.

.::. .. . .. . . . . . . . -. • :: : : : .. .:.. :. . . . . _. : . !: . - -. .. . . . . . , . ,.

-160
Ii
Table C17. Terminal-to-terminal insulation resistance.

Capacitance rating Minimum insulation resistance

Characteristic E At 250 C
0 to 0.6 microfarad ----------- 25,000 megohms
Greater than 0.6 microfarad --------- --- 15,000 megohm-microfarads 1_
At 850 C
0 to 0.15 microfarad -------- ---------- 2,000 megohms
Greater than 0.15 microfarad ------------ 300 megohm-.microfarads 1/
Characteristic K At 250 C
0 to 0.6 microfarad --------- ---------- 25,000 megohms
Greater than 0.6 microfarad --------- --- 15,000 megohm--microfarads 1/

At 125°C
0 to 0.08 microfarad ------------------ 250 megohms
Greater than 0.08 microfarad ------------ 20 megohm-microfarads _/
Characteristic F At 25°C
0.33 microfards, and less --------- ----- 6,000 megohms
Greater than 0.33 microfarads - - - - - ------ 2,000 qwegohm-microfarads 1/
At 850 C

0.033 microfarads and less ---------- --- 600 megohms


Greater than 0.033 microfarads ---------- 20 megohm-microfarads 1/
Characteristic G At 250 C
0.33 microfarads and less --.-.-.-.--------- - 4,500 megohms
Greater than 0.33 microfarads - - - - - - - 1,500 megohm-microfarads 11
At 850 C
0.33 microfarads and less --------- ----- 450 megohms
Greater than 0.033 microfarads ---------- 15 megohm-microfarads 1/

1/ Product obtained by multiplying the capacitance in microfarads by the


insulation resistance in megohmg.

"161

-1 . 2.
7. T7. -W 4 - W-.

Table C18. Style capacitors.

Available terminal
Case size identification number
Part DC voltage Vibration Characteristic Terminal
number rating Capacitance grade E K F G B D E
Volts JJF 1

Table C19. Case dimensions and retainer part number.

Case dimensions (in inches) Retainer


Case W ±.062 T ±.062 L ±.062 A +.6625 part
size -. 187 number

.9Q

74

1{- 9 . . . . . . .
Table C20. Millimeter equivalent of decimal inches.

"INCHES MM INCHES MM INCHES MM


.015 .38 2.281 57.94 5.500 139.70
.016 .41 2.375 60.33 5.750 146.05
.025 .51 2.500 63.50 5.875 149.23
.031 .79 2.625 66.68 6.000 152.40
.045 1.14 2.719 69.06 6.250 158.75
.047 1.19 2.750 69.85 6.375 161.93
.062 1.57 2.875 73.03 6.500 165.10
.0625 1.59 3.000 76.20 6.750 171.45
.094 2.39 3.062 77.77 6.875 174.63
.125 3.18 3.125 79.38 7.000 177.80
.187 4.75 3.188 80.98 7.250 184.15
.188 4.78 3.250 82.55 7.375 187.33
.213 5.41 3.375 85.73 7.500 190.50
.281 7.14 3.500 88.90 7.750 196.85
.391 9.93 3.625 92.08 8.000 203.20
.438 11.13 3.656 92.86 8.250 209.55
.625 15.88 3.750 95.25 8.375 212.73
.812 20.62 3.812 96.82 8.500 215.90
.844 21.44 3.875 98.43 9.000 228.60
.906 23.01 3.938 99.03 9.250 234.95
1.062 26.97 4.000 101.60 9.375 238.13
1.125 28.58 4.125 104.78 9.500 241.30
1.188 30.18 4.250 107.95 9.625 244.48
1.250 31.75 4.375 111.13 10.125 257.18
1.344 33.14 4.500 114.30 10.375 263.53
1.375 34.93 4.562 115.87 10.750 273.05
1.469 37.31 4.625 117.48 11.000 279.40
1.625 41.28 4.750 120.65 11.250 285.75
1.750 44.45 4.844 123.04 12.625 320.68
1.812 46.02 4.875 123.83 12.875 327.03
1.938 49.13 4.969 126.21 13.125 333.38
1.967 49.96 5.000 127.00 13.500 342.90
2.000 50.80 5.094 129.39 13.750 349.25
2.062 53.37 5.125 130.18 15.625 396.88
2.125 53.98 5.250 133.35 16.750 425.45
2.250 57.15 5.375 Y"' 53

NOTES:
1. Dimensions are in inches.
2. Shape of retainer optional provided specified dimensions are met.
Spade lugs shall be rigid and double welded, double riveted, single
riveted and soldered,,or welded and single riveted to the retainer.
3. Minimum thickness of retainers shall be .045 (1.14mm).
4. When two part numbers are applicable to the same retainer, both part
numbers shall be marked on the retainer. Retainers shall be marked
on the outer surface.
5. When used, rivets shall curl-over .020 (.51mm) ±.015 (.38mm)
beyond the inside of the retainer.

163

..................
,............... .......... . •.. °... .-.-..-..- . .-- °•• • !
S.:,•: '_'•.- : , .: .?.: , "-..s• : • " -• • '• - " - ' . "'' ", '- : : - " " . - .1
At•.:., A PNI

•.,_

A:.

4.

4.16
"HIGH VOLTAGE CONNECTOR CRITERIA DOCUMENT

1. SCOPE

1.1 Scope. This specification covers circular electrical connectors with


a single solder or brazed contact. These connectors are for use in airborne high
voltage electrical power systems (see 6.1).

1.1.1 Temperature. These connectors are rated for specified operation within
a temperature range of -65°C (-850 F) to eithet 125°C (257 0 F), 1750 C (347 0 F), or 200C
(392°F) depending upon the class. The upper temperature is the maximum internal hot-
spot temperature resulting from any combination of electrical load and ambient
conditions.

Service Life. These connectors are to meet the specified requirements for
1.1.2
a service life of 1750 operating hours at high voltage.

1.2 Classification. Electrical connectors shall be of the following sizes,


types,and styles as specified (see 6.1).

1.2.1 Types
1. Receptacle
Style A- Straight
Style B- Right Angle
2. Plug
Style A -Straight
Style B - Right Angle

1.2.2 Sizes

No. 16-16
No. 12-12
No. 8-8
No. 4-4
No. 0-0

1.2.3 Coupling. Connectors shall have threaded couplings torqued to proper


pressure with spanner wrenches and locked in place with wire seals.

166

*1•o % , ' o- % % , " % • " o "" °*"% " °% °° ' , . • . ° °°o - , , • , '
.... . . ... . .. .. . . . . .. ...
>11

e1.2.4 Recept.acle Mounting. Receptacle mounting shall be designated as follows:

~.
..m .. Flange
Jam Nut

1.3 Wire range accommodations. The wire ranges given in table D-1 shall be
accommodated by the connectors as indicated.

TABLE D-1 Wire range accommodations

Contact Wire OD of finished wire (inch)


Size Size Min Max
16-16 20
18 0.064 0.130
16
12-12 14 0.114 0.170
12
8-8 10 0.164 0.255
8
4-4 6 0.272 0.370
4
0-0 2 0.415 0.550
0

2. APPLICABLE DOCUMENTS

2.1 Issues of documents. The following documents of the issue in effect on


date of invitation for bids or request for proposal form a part of this specification
to the extent specified herein:

SPECIFICATIONS
FEDERAL
QQ-P-416 - Plating, Cadmium (Electrodeposited).
QQ-S-365 ,- Silver Plating, (Electrodeposited), General
Requirements for
QQ-S-571 - Solder, Tin Alloy: Tin-Lead Alloy; and
Lead Alloy
"QQ-S-763 - Steel Bars, Wire, Shapes, and Forgi ngs,
Corrosion Resisting

167
•ti•,••,.-.
,.;•.,-, .,-',,"
,'.:..,•.,, , .. ".. - " " ".-.-. •., †††,†,-†-,†-."†††.-††-†††††.†,,†††'††-,††††"†,†-.††,†-†-.'-.
'..-.-.. , ".,.. ".,
WI II

MILITARY

MIL-S-7742 - Screw Threads, Standard, Optimum Selected


Series; General Specification for
MIL-C-23216 Contacts, Electric Connector, General Specification
"for
MIL-G-45204 - Gold Plating, Electrodeposited
MIL-C-45662 - Calibration System Requirements
MIL-C-55330 - Connectors, Preparation for Delivery of

STANDARDS
MILITARY
MIL-STD-810 Test Methods for Electronic and Electric Component
Parts
MIL-STD-454 - Standard General Requirements for Electronic Parts
MIL-STD-456 - Electronic Par ti, Date and Source Coding for
MIL-STD-1285 - Marking of Electrical and Electronic Parts
MIL-STD-1353 - Electrical Connectors and Associated Hardware,
Selection and Use of
MS3197 Gage Pin for Socket Contact Engagement Test

(Copies of specifications, standards, drawings, and publications required by suppliers in


connection with specific procurement functions should be obtained from the procuring
activity or as directed by the contracting officerO)

2.2 Other publications. The following documents form a part of this specification to the
extent specified herein. Unless otherwise indicated, the issue in effect on date of
invitation for bids or request for proposal shall apply.

H28 Handbook - Screw Threads, Standard, Optimum Selected Series;


ASTM-D 1868-Detection and Measurement of
Discharge (Corona) Pulses in Evaluation of Insulation
Systems.
ASTM-D 3382-75 - Measurement of Energy and Integrated Charge Tran-
sfer Due to Partial Discharges (Corona) Using Bridge
Techniques.

"168
ASTM-D 3426 - Dielectric Breakdown Voltage and Dielectric
Strength of Solid Electrical Insulating

. :Materials Using Impulse Waves.

NEMA Publication No. 109 - IEEE-EEI-NEMA Standard Basic Insulation Level.

(Application for copies should be addressed to the Superintendent of Documents,


Government Printing Office, Washington, D.C. 20360).

INSTITUTE OF ELECTRIC AND ELECTRONIC ENGINEERS


IEEE STD-4 IEEE Standard Techniques for High Voltage Testing

1- °

-'!

169

W.N....
;..,

3. REQUIREMENTS

3.1 Specification Sheets. The individual item requirements shall be as speci-


fied herein and in accordance with the applicable specification sheets. In the event
of conflict between the requirements of this specification and the applicable speci-
fication sheets, the latter shall govern.

3.2 Qualification. The connectors and accessories furnished under this speci-
fication shall be products which are capable of being qualified for listing on the
applicable qualified products list (QPL).

3.3 Materials.
The material for each part shall be as specified (see 3.1).
When a definite material is not specified, a material which will enable the element to
meet the requirements of this specification shall be used. Acceptance or approval
of a constituent material shall not be construed as a guarantee of the acceptance
of the finished product.

3.3.1 Dissimilar Metals. When dissimilar metals are employed in intimate Lon-
tact with each other in a connector or in a mated pair of connectors, suitable pro-
tection against electrolytic corrosion shall be providec' as specified in requirement
16 of MIL-STD-454.

3.3.2 Nonmagnetic Materials. All parts shall be made of materials which are
classed as nonmagnetic (see 3.3.5).

3.3.3 Contact Materials. Contacts shall be made of suitably conductive materials.

3.3.3.1 Contact Plating.

3.3.3.1.1 Contact Plating (Solder Type). Contacts shall be silver plated in


accordance with QQ-S-365 or gold plated in accordance with MIL-G-45204 over silver

plating in accordance with QQ-S-365. The resultant minimum thickness of contact


plating shall be 100 micrGinches. Accessory members of the socket contacts need
not be pldted but shall comply with the requirements for dissimilar metals specified
in 3.3.1.

3.3.4 Diplectric Materials.

3.3.4.1 Plug and Receptacle•


Insert and receptacle materials shall be high
grade dielectric having hardness, electrical, and mechanical characteristics suitable
for the purpose intended.

170
•• . ., .. °•." • '. . ". .. . .". . . . . .".. -.
3.3.4.1.1 Plug. The plug mating face shall be a resi;ient semi-flexible
material within a Shore A Durometer range of 35 to 85. The plug shall be a part
. of the cable assembly and shall be supplied with covers. The plug shall have a
female socket and sha!E include parts such as a cover with a shorting bar between
contact and shield.
3.3.4.1.2 Receptacles. A receptacle shall be a unit which is fixed on either
the aircraft or electrical/electronic assembly. It shall have one male contact and

shall include parts such as a cover as required.

3.3.5 Shells and Coupling Rings. When specified (see 1.2.1), shells and
coupling rings shall be made of nonmagnetic corrosion-resisting steel in accordance
with QQ-S-763, 300 series classes, or QQ-S-764, 303 series and 203 EZ.
3.3.5.1 Finish. The resultant finish on all connectors shall be electrically
conductive. The finish of connectors with corrosion-resistant materials, shells and
coupling rings, such as aluminum, shall be cadmium plated in accordance with QQ-P-416,
Type 2, Class 3, color-black. All other corrosion-resisting steel connectors shall be
passivated. External screws may be stainless steel in lieu of the finish specified.

3.4 Design and Construction. Connectors and accessories shall be designed and
constructed in accordance with this specification and the applicable specification
sheets, and shall be capable of withstanding normal handling incident to installation
and maintenance in service.

3.4.1 Contacts. Contacts shall conform to Figure D-1. Contacts shall be designed
so that neither the pin nor socket contact shall be damaged during mating of counter-

part connectors. Pin and socket contacts shall have enough tolerance so that gages
are not required. The engaging or disengaging force oi the contracts shall not
exceed 20 pounds, (see 3.20).

3.4.1., Plug Mating End.


The entering end of the plug socket contact shall be
rounded or chamfered to allow for misalignment of the entering pin. The socket con-
tacts shall provide the spring action for maintaining the contacting pressure between
the pin and the socket.

3.4.1.2 Receptacle Pin Contacts.


Pin contacts shall have their tip ,.ished
to a spherical radius, with allowable flat of 1/8 inch less than the pin diameter.
The pin contact shall be mechanically held in the receptacle.

171
.03 MAX DIA VENT HOLE SHELL SEE DETAIL B
"O6.°O
M IN R S IZES 8,4 AND O0K o
PTIONAL) APPROX
i SPHERICAL H
RAO

I qo-'F \ - A

SEE DETAIL A SEE NOTE SEE DETAIL A

SOCKET DETAIL A DETAIL B PIN


SOLDER CUP PIN.END

A I. C2/1 D E F H J 3 : K
Contact ±. 001 %a . n
Mi . 063 Dia Plug & rcpt Max plug Dia of
size Dia Dia Dia -. 000 Min Max Min Max and rcpt flat

I16 1 69 7 I 194"127
.0625 .069 .250 :.096 .116 .250 .212 .281 .032 Max
l0 :.112 .375 .130
4' 16S 0625 .127:.069 .250 .096 .150
.116 ..062,062.125 .281
,379 .032
- 032Max
Max
8 .142 :.310-.205 .500 .243 .259 .062 .125 .375 .032 Max
4 .225 ;.4411.3281 .625 .370 .397 .062 .125 .375 .105t. .021
0 . 357 97
,.5 5,.5 10 . 5 5 0 . 0 6 2 1. 12 5 k
6".4.42".6 . 28 1 .2 3 7 . 0 2 1
Applies after plating.
' / Used for calculating mechanical spacing between contacts and between S1/
contacts
- i• and shell.
3/ RMpresents the distance from the end of the shell to the point at which the
mating pin engages the socket contact spring.
4/ Dimensions shown are typical for shell sizes 8S, 10S, 1OSL, 12S, 14S and 16S.

NOTES:
1. Dimensions are in inches.
2. Sizes 12 and 16: G max = 2/3 E, radius of cutout optional.
Sizes 0, 4, and 8: Cutout optional.

FIGURE D-1 SOLDER CONTACT (PIN AND SOCKET) CONFIGURATION

".17

S*7z
3.4.1.3 Solder Cups. Solder cups shall be designed so that during soldering
no components will be dam&,--ki no liquid solder will escape. The solder cups
shall be as indicated in ' ,l. The solder cups of sizes 0, 4,and 8 shall be
provided with a venthole or with equivalent provisions to prevent trapping of air
during solcnring. The interior surface of (Surface D, Detail A, FigureD1 of solder

cups for sizes 16 and 12 shii!l be completely tinned over 100 r.cent of the full circle
portion and for at least 50 percent of the cutout section of the solder well area; for
sizes 0, 4, and 8, the interiors shall be completely tinned with soider conforming to
composi~to.-i Sn60 of QQ-S-571, or better commercial grade. Only alcohol and resin sir.,l be
used as a flux. No excess solder shall l on the exterior of the solder cup.

3.4.1.4 Contact Spacing. Unless otherwise specified in the detailed specification,


minin•zm sechanical spacing and creepage distance shall be as shown in Table D2.

TABLE D2. MINIMUM CONTACT SPAC;4G

Minimum contact spacMig (inch)


Ctntact to Shellk''
Sepvice Rating

KV

10 0.5
20 1
50 2
100 4
150 6
200 8

(1)Distance is total surface distance frim contact to shell.

3.4.1.5 Contact Alinement. Inserts for socket contacts shall provide an over-
all sideplay of the soclet contacts of 0.005 to 0.015 inch from the required position
to facilitate altgment Vr mting pin contacts.

3.4.2 Plug and Receptacle Insulation. Plugs and receptacles shill be of: i)
void free materials in the connector, and (b) free o* trar'ped air "thwn mated.

3.4.2.1 Plug lnsulatio,. Plugs shall be made if non rmovable, resilient,


elastomeric materials molded to the cable. The socket ccrtact shall he mounted on
ýhe plag.

173
3.4.2.1.1 Shield Termination. The shield shall be terminated in a manner to
cover all sharp ends to prevent them from emitting electrical dicharges.

3.4.2.1.2 Semi Conducting Layer.Cable semi conducting layer under the shield
shall be removed to provide aderuatc distance between the center conductor and the
shell/shield termination.

3.4.2.1.3 Molded Configuration. A molding process shall be used to bond the


cable primary insulation to the plug insulation. A semi conducting laye may cover
the bonded joint to provide a better bonding surface.

3.4.2.2 Receptacle Insulation. Receptacle insulation shall be of a seamless


rigid voidless material. A vold:ess fit shall exist between the shell and the
molded insert to eliminate corona. Semiconducting materials may be added to achieve
the voidfree configuration. The pin contact sha'l be mounted in the receptacle.

3.4.2.3 Sharp Corners. Sharp corners shall be eliminated to prevent electric


partial discharges, or corona.

3.4.3 Screw Threads.Screw threads intended to mate with parts of another


approved manufacturer shall be UNEF, UNF, or NEF, class 2A or 28, conforming to
MII.-S-7742, except that 1-3/4-18 and 2-18 threads shall be UNS class 2A or 2B,
conforming to Handbook H-2b. Screw threads shall be checked after plating by means
of ring and plug gages nnly, in accordance with Handbook H-28. Slight out-of round-
ness beyond the tolerances of MIL-S-7742 is acceptable if the th; s-ads can be checked
without forcing the thread gages. Screw threads may be relieved provided the relief
does not interfere with proper performance of the screw threads.

2.4.4 Shell Oesiojn. Connector shells shall be seamless and retain their inserts
in a positive manner.

3.4.4.1 Lubrication. All internal coupling ring threads shall be coated with a
suitabln lubricant.

3.4.5 Coilipq Connections. ThrNa" A coupling -ings shall be knurled, and


designed so that the pin and socket contv. ;s shall -ngag. or disengage as the ring
is respectively tightened or loosened. The coqpling rings of connector plugs shall
be captive to the shell.

174
3.4.5.1 Safety of Coupling Rings. All threaded coupling rings shall be
designed for safety wirlng. At least two holes shall be provided for shell sizes
14 and smaller, and at least three equally spaced holes for connector sizes 16
and larger. These holes shall be of a diameter sufficient to accoamodate 0.032
inch diameter wire.

3.4.5.2 Engagement Seal.


Connectors shall contain sealing means so that
engaged connectors comply with the requirements specified herel7. The design of
the seal shall be such that in mated connectors all air paths between adjacent
contacts and between contacts and shells are eliminated. There shill be inter-
facial mating of the engaged connector insert to provide dielectric under com-
pression of 0.010 inch per inch 1lngth insert minimum. Connector plus shells
with -'Jreaded coupling rings shall b- provided with a static peripheral seal to
ensure shell to shell sealing.

3.5 Intermateability and InterchaMqe'.bility.

3.5.1 Interme:eability. Connectors shall be inte-mateable. Where dif-


ferent types of connectors (front or rear release) are used in a mated pair of
cennectors, the minim•L performance requirements (temperature, sealing, etc.)
must be met.

3.5.2 Intrchanoeability.
All connectors and accessories having the same
specified part number shall be completely intr.rchangeabie with each other with
respect to installation (physical) and perfouafice (function) as specified
herein.

3.6 DisgSMI~t. The axial tension required to separate the plug *ell
from a receptable shall be 12 pouhds, maximum, when tested in accordance with
4.6.2. A thin film insulating grease may be used to ltbricate the plug surface.

3.7 Thermal Shock.


There shall be no evidence of damage detrimental to the
operation of the connector after being subjected to the temperatur\, extremes in
accordance with 4.6.3.

175

. . . . .
3.8 Contact Retention. The axial displacement of crimp contacts shall not
exceed 0.025 inch and contacts shall be retained in their inserts when subjected
to the axial loads specified in accordance with 4.6.4.

3.9 Dielectric Withstanding Voltage. Connectors shall show no evidence of


-~ breakdown or flashover when subjected to the test voltages and altitudes in
accordance with 4.6.5. Corona and partial discharges shall not be considered as
breakdown.

3.10 Partial discharges and corona. Connectors shall show no evidence of


material deterioration or damage when subjected to the test voltages and alti-
tudes in accordance with 4.6.6.

* 3.11 Pulse. Co.,nectors shall show no evidence of breakdown or flashover


when subjected to the tist voltages in accordance with 4.6.7.

*3.12 Vibration. Hated connectors shall not be damaged and there shall be
* no loosening of parts due to vibration. Counterp~art connectors shall be retained
in full engagement,, and O~ere O~all be no interruption of electrical continuity
*longer
* . *
.*. than
* 10 microseconds te*en tested in accordance with 4.6.8.
i-* * -. :

3.13 Shock. Mated connectors shall not be damaged and therz shall be no
loosening of parts, nor shall there be an interruption of electrical continuity
* ~longer than 10 microseconds d :lrog the exposure to mechanical shock when tested
in accordance with 4.6.9.

3.1.4 Humiadity. Mated connectors shall withstand 120 percent rated voltage
in table D-3 for at least 5 ministes after being tested in accordance with 4.6.10.

r.-V
TABLE 0-3. Test Voltages After Humidity

' Service rating Test Voltages


Kilovolts Kilovolts (crest)

10 15
20 25
50 60
100 120
150 180
"200 240

3.15 Contact resistance. Contacts in the mated condition shall meet the
ambient (25 0C) contact resistance requirements of MIL-C-23216. The potential
drop of contacts shall not exceed 125 mV initially or 200 mV after conditioning
when tested in accordance with 4.6.11.

3.16 Durability. Counterpart connectors shall show no mechanical or elec-


trical defects detrimental to the operation of the connector after 500 cycles of
mating and unmating in :ordance with 4.6.12.

3.17 Corrosion. Connectors shall show no exposure of basis metal caused by


! corrosion which will affect performance when tested in accordance with A.6.13.

3.18 Insulation Resistance. The insulation resistance at 250 C (77 0 F) shall


be greatey than 500 megohms when tested in accordance with 4.6.14.2.

3.19 Moisture Resistance. Mated connectors with any rear accessory hard-
tore assembled shall maintain an insulation resistance of 100 megohns or greater
at 250C after being subjected to the moisture resistance test in accordance with
4.6.15.

3.20 Contact Enpajin2 and Separating Forces. The socket contact engaging
and separating forces shall be within the applicable limits specified in table 04
when tested in accordance with 4.6.16.

".177
ji
TABLE D4: Contact Engagement and Separation Forces.
Minimum separation Maximum average Maximum engagement
Contact force (ounces) engagement force force (ounces)
mating Minimum diameter (ounces) Maximum diameter
end size MS3197 pin Maximum diameter MS3197 pin
MS3197 pin

16 2 33 48
12 3 56 80
8 5 --- 160
4 10 --- 240
0 15 --- 320

3.21 Shell Conductivity. Mated connectors shall be electrically con-


ductive from the plug accessory thread to the receptacle mounting flange
or to the accessory thread on the cable connecting plug. The overall dc
resistance shall not exceed 0.05 ohms when measured in accordance with 4.6.17.

3.22 Altitude. When testel as specified in 4.6.18, the mated connectors


shall meet the partial dischar•e and voltage breakdown requirement. Any
evidence of dielectric breakdown or flashover shall be cause for rejection.

3.23 Random Vibration. When tested as specified in 4.6.19, a current


discontinuity of 1 microsecond or more, disengagement of the mated connectors,
evidence of cracking, L.-eakinq, or loosening of parts shall be cause for
rejection.

3.24 !%rking. Each connector shall be legibly and permanently marked

on the shell or coupling ring in accordance with MIL-STD-1285 and; MIL-STD-456.

77-

178
3.25 Workmanship. Loose contacts, poor molding fabrication, loose materials,
defective bonding, damaged or improperly assembled contacts, peeling, or chipping
of plafi " or finish, galling of mating parts, nicks and burrs of metal parts and
post molding warpage will be considered adequate basis for rejection of items of
quality inferior for the purpose intended.
4. QUALITY ASSURANCE PROVISIONS

4.1 Responsibility for Inspection. Unless otherwise speci ied in the contract,
the contractor is responsible for the performance of all inspection requirements as
specified herein. Except as otherwise specified in the contract, the contractor may
use his own or any other facilities suitable for the performance of the inspection
requirements specified herein, unless disapproved by the Government. The Government
reserves the right to perform any of the inspections set forth in the specification
where su-h inspections are deemed necessary to assure that supplies and services
conform to prescribed requirements.

4.1.1 Test Equipment and Inspection Facilities. Test and measuring equipment
and inspection facilities of sufficient accuracy, quality and quantity to permit
. performance of the required inspection shall be established and maintained by the
contractor. The establishment and maintenance of a calibration system to control
the accuracy of the measuring and test equipment shall be in accordance with
MIL-C-45662.

4.2 Classification of Inspection. The inspection of conneconrs shall be classi-


fied as follows:

a. Qualification inspection.
b. Quality conformance inspection (4.4).

4.2.1 Inspection Conditions.


Unless otherwise specified, all inspections shall
be performed under any combination of conditions within the following ranges. Any
specified condition shall not affect the other two ambient ranges.

Temerature: 150 to 35 0 C (590 to S50F).


Relative humidity: 30 to 80 percent.
Barometric pressure: 650 to 800 mm of mercury.

17-)
zJ
;" . "" °"
o .4 "• "" o °""* "= "" "• " " * * " " = • . . . . " . " - .. . . 4
,,, %,-,,,,.. ,,,,, ,. ,, ., ,,.,,,.,,,.,.
.. .,,..,,,. ,,,,., ,',,-.- -...- -,-, .. '.,,+ .' ".-.., ',, ., .. .. .. ',,,
4.3 Qualification Inspection. Qualification inspection shall consist of the

examinations and tests performed in the sequence specified in TableD5 on the qual-
ification test samples specified in 4.3.1.

4.3.1 Qualification Samples. Samples of each item for which qualification 4


desired shall be tested in the sequence specified in Table D5,as applicable. Speci-
fic details on preparation of samples shall be as follows: Each connector subjected
to qualification testing shall be provided with a counterpart connector for those
tests requiring mating assemblies. The counterpart connectors provided for this
purpose shall be new, previously qualified connectors or new connectors submitted
for qualification testing. Manufacturers not producing mating connectors shall
submit data substantiating that tests were performed with approved counterpart
connectors.

4.3.1.1 Wire-to-contact assembly. Unless otherwise specified herein, connectors


shall be wired with approximately 3 feet of wire as applicable.

Solder Contact Connectors. Qualification samples and qualification


4.3.1.2
test3 for solder contact connectors shall consist of two complete connector assemblies
of receptacles and straight plugs for which qualification is desired, in each shell
size, which shall be subjected to the tests of Table D5. Qualification testing of
these samples will admit qualification of other shell types. Testin% of solder
contacts need not be performed if compliance of similar contacts has previously
been demonstrated in conjunction with qualification testing of connectors of a
different class.

4.3.1.3 Socket Contacts. Fifty of each socket contact size and configuration
used in the solder contact connectors for which qualification is desired shall be

subjected to the tests of Table 05. Sockets which are not completely assembled prior
to Installation in the insert may be provided ana tested in connectors.

4.3.2 Qualification ReJe•.tion. There shall bee no failures during any examina-
tion or tests of the connectors or accessories submitted for qualification tests.
After notification of any failure, the agent r-sponsible for qualification testing
(see 6.3.1) shall receive details of corrective action from the manufacturer before
initiating any further tests deeme4 necessary to assure compliance with connector
requiremnts.

180

•'.,.:,* ' s.".o. ,.-"- -,• • • " %-; "


"- ".-:;:
".. ". 5'.'.5'-' .- 5'','- -"",...* "-.-.'
*" ''....- . *-.5-•'.'. *.'.' '
...-. . = ."''
5.'""
"TABLE D5: Qualification Inspection for Solder Contact Connectors
Requirement Test
Inspection paragraph paragraph

Visual and mechanical 3.1,3.3,3.4,3.5 4.6.1


3.24 and 3.25
Disr- -ement (MS3187 plug only) 3.6 4.6.2
ThF .'shock 3.7 4.6.3
Contact retention 3.8 4.6.4
Dielectric withstanding voltage 3.9 4.6.5,1
?artial discharge 3.10 4.6.6
Pulse 3.11 4.6.7
Vibration 3.12 4.6.8.1
Dielectric withvtanding voltage 3.9 4.6.5.1
Shock 3.13 4.6.9.1
Humidity 3.14 4,6.10
P4.lectric withstanding voltage 3.9 4.6.5.3
Partial discharge 3.10 4.6.6
Contact resistance 3.15 4.6.11

Durability 3.16 4.6.12


Corrosion 3.17 4.6.13
Contact resistance 3.15 4.6.11
Insulation resistance 3.18 4.6.14
Moisture resistance 3.19 4.6.15
Contact engaging and separating forces 3.20 4.6.16
Shell Conductivity 3.21 4.6.17
Altitude 3.22 4.6.18
Dielectric withstanding voltage 3.6.5.2 4.6.5.2
Random vibration 3.23 4.6.19
Visual and mechanical 3.1,3.3,3.4 4.6.1
3.5,3.24
and 3.25

181

'.S• S•'1.. *......-


*** ,* .-. • •- ..........-..
4 ° - . •
•. ,
•4
.4
.. '. *
1 , -. o .*'"* °.*' , . 2 ° o. °* •, .' * . ° .
4.4 Qualty conformance inspection.
J1

4.4.1 Inspection of product for delivery. Inspection of product fcr


delivery shall consist of groups A and B inspection.

4.4.2 Inspection lot. An inspection lot shall consist of all connectors


covered by this specification, produced under essentially the same conditions
* and offered for inspection at one time. In-process controls, unrelated to

lot sizes of finished connectors, may be used, provided an equivalent or


tighter AQL level is maintained.

4.4.2.1 Group A inspection. Group A inspection shall consist of the


'ý" examination of product in accordance with 4.6.1.

4.4.2.1.1 If an inspection lot is rejected, the supplier


Rejected lots.
may rework it to correct the defects, or screen out -T.he defective units and
resubmit for inspection. Resubmitted lots shall be inspected using tightened
"inspection. Such lots shall be kept separate and shall be clearly identified
as reinspected lots.

.. .. h-
4.4.2.* Group B inspection. Group B inspection shall consist of the
applicable tests specified in table D6 and shall be made on the units which
have been subjected to and have passed Group A inspection.
TABLE 06: Group B Inspection
Requirement Test
InspMtion Caragraph paragraph
Dielectric withstanding voltage 3.9 4.6.5.4
Partial discharge 3.10 4.6.6
Insulation Resistance 3.18 4.6.14.2

4.4.2.2.1 If an inspection is rejected, the supplier


Rejected lots.
m•y rework it to correct the defects, or screen out the defective units,
and resubmit for reinspection. Resubmitted lots shall be inspected using
"tightened inspection. Such lots shall be separate from oew lots, and shall
be clearly identified as reinspected lots.

4.4.2.2.2 Disposition of sample units. Sample units which have passed


the group B inspection may be delivered on the contract or purchase order.
182

.1 bk %L7 -- h -St 4 ~ * * *
4.5 Periodic inspection. Periodic inspection shall consist of group C.
Except where the results of these inspections show noncompliance with the appli-
cable requirements (see 4.5.1.4), delivery of products which have passed group B
shall not be delayed pending the results of these periodic inspections.

Group C inspection. Group C lnspect~in shall cor.sist of the tests


4.5.1
specified in table D7 in the order shown. Group C inspection shall be made on
sample units selected from inspection lots which have passed the groups A and B
inspection. Group C inspection reports shall be forwarded to the qualifying
activity every 18 months as specified in the sampling plan.

4.5.1.1 Sampling Plan. Every 18 months, mated connector sample units which
have passed groups A and B inspection shall be subjected to the tests specified
in table D7. Samples shall be selected in sufficient quantity to provide two
samples per applicable test group, as determined by the contact type and the
class of the samples to be tested.
TABLE D7. Group C Inspection

kequirement Test
.- Inspection paragraph, paragraph
Insulation resistance 3.18 4.6.14.2
Dielectr•c withstanding voltage 3.9 4.6.5.1
Partial 0•. .- arge 3.10 4.6.6
Contact -it-t-Won 3.8 4.6.8
Shell cora.-kitvity 3.21 4.6.17
Durability 3.16 4.6.12
Moisture resistance 3.19 4.6.15
Humidity 3.14 4.6.10
Corrosion 2.17 4.6.13

4.5.1.2 Failures. if one or more salple units fail to pass group C


inspection, the sample shall be considered to have failed.

4.5.1.3 Disposition of sample units. Sample units which have been


subjected to group C inspection ;hall not be delivered on the contract or
purchase order.

d Noncoflipliance. If a sample falls to pass group C Inspection,


4.5.1.4
the manufacture. ill take corrective action on the materials or processes,
o. both, as \ '• and on all units ol the product which can be corrected
.

and which 183


d,,:.,.. . . .. - ; . . . ., .,. • .... ,:,... .- ,---, ,. , ' • ,-.-.,. -. '.-.' - ,-: - -. , ,... . , . .
manufactured with essentially the same materials, processes, etc. and which are
co.ýsidered subject to the same failure. Acceptance of the product shall be dis-
continued until corrective action, acceptable to the Government, has been taken.
After the corrective action has been taken, group C inspection shall be repeated on
additional sample units (all inspection, or the inspection which the original sample
failed, at the option of the.Government). Groups A and B inspections may be rein-
stituted; however, final acceptance shall be withhe!d until the group C reinspection
has shown that the corrective action was successful. In the event of fail-ire after
reinspection, information concerning the failure and corrective action shall be
furnished to the cognizant inspection activity and the qualifying activity.

4.5.2 Packaging Inspection. The sampling and ir~p;.-ction of the preservation-


packaging; packing and container marking shall be in accordance with the requirements
of MIL-C-55330.

4.6 Methods of Examination and Tests.

4.6.1 Vis~ial and Mechanical Examination. The connectors and accessories shall
be visually and mechanically examined to ensure conformance with this specification
and the applicable military standards (see 3.1, 3.3, 3.4, 3.5, 3.24 and 3.25). In-
process controls of component parts, unrelated to lot sizes of finished cr-nectorst
may be utilized in lieu of examination of these components in the finishe-. connectors
to assure conformance of these component parts.

4.6.2 Disengagement. The plug shall be fully mated to a securely mounted


receptacle. A gradually increasing axial tension shall be applied to the plug and
the force at separation measured (see 3.6).

4.6.3 Therml Shock. Accessories or unmated connectors shall be tested in


accordance with mewthod 107, condition A of MIL-STD-810 except that the temperature
extremes shall be as specified in Table D-3 . At the completion of the last cycle,
the connectors shall be returned to room temperature for inspection (see 3.7).

184
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S* " •• ," "- •, ,'', ''". ',J'- %ot.'."' , , J , 4 ,*. .. '.," .'.* ' ". ";' ".'' ' . /""-" " '. * -" " .' . ...
TABLE D-8 Temperature Extremes

:""~; Temperature
Type Extremes Degrees C Degrees F
+0 +0
.; •.i ABB
A, Low -65 3 -853
r,%:'..,+5
;;:',Hi gh-125 +3
High -125 -0 +257 -0
"• ~+0
Low -65 +0 -85
A, B -3 -5
+3 +5
High -175 -0 -0
+0 +0
Low -65 -853
A, B
+3 +5
High +200 +302
-0 -0

4.6.4 Contact Retention.


Axial loads in accordance with TableD-9 shall be
applied to the contact. The connector shall have the contact in place during the test.
The load shall be applied at a rate of approximately 1 pound per second until the
specified load has been reached (see 3.8)

4.6.4.1 Connectors (Accessory Tightened). The axial load shall be applied


to the mating end of the contact with the connector accessory tightened. The load
shall be applied after the slack in the contact has been taken up, and the displace-
went of the contact shall be measured under load after the load has been applied
for a minimum period of 5 seconds.

TABLE D-9 Contact Retention Axial Loads

Contact Mating Minimum axial load (pounds)


end size
16 10
12 15
8 20
", 4 20
., 0 25

'1
:i

S~185
4.6.5 Dielectric Withstanding Voltage.

4.6.5.1 Dielectric Withstanding Voltace (Sea Level). Wired, mated connectors


shall be tested in accordance with method 3001 of MIL-STD-1344 with the following
details and exceptions:
a. The magnitude of the test voltage shall be as specified in
Table D-l0.
b. The test voltage shall be maintained at the specified value
"for one minute minimum.

4.6.5.2 Dielectric Withstanding Voltage (AltiLude). Mated connectors and


unmated connector halves with pin contacts shall be tested in accordance with
method 3001 of MIL-STD-1344 with the following details:

a. The magnitude of the test voltage shall be as specified in


Table D-10.
b. The test voltage shall be maintained at the specified value for
one minute minimum.
c. The leads of all test circuits shall " brought out through the
wails of the chamber, There shall be no wire splices inside
toe chamber.
d. Only the engaging faces of connectors shall be suý ected to the
70,000 5000 feet altitude.
e. The test art~zle shall be exposed to altitude condivions for 20
minutes prior to test.
4.6.5.3 Dielectric Withstanding Voltage (After Humidity). The mated connectors

shall show no evidence of breakdown when the vo.-;,ge indicated for the applicable
service rating in Table D-3 is applied between the shell and the contact in accor-
dance with method 3001 of .,L-STD-1344 except the test voltage shall be applied
for 5 minutes (see 3.14).

4.6.5.4 Dielectric Withstanding Voltage (Group B Inspection). Mated connector


assemblies shall show no evidence of breakdown when the applicable test voltage of
200 percent rated voltage as shown in Table DIO is applied between the shell and the
contact in accordance with met red 3001 of MIL-STD-1344. The period of application of
*" voltage shall be one minute miimum (see 3.9).

186

•,, $86

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•'•'.'**.'.
. ., ...... " '"" "* *
TABLE D1O: Dielectric Withstanding Test Voltages
Service rating, Test Voltages,
Kilovolts Kilovolts (Crest)
10 16
20 32
50 80
100 160
150 240
200 320

4.6.6
Corona and partial discharge (see 3.10). Connectors shall be
tested in accordance with ASTM D1868, (Circuit, Figure 1). The detector
used shall have a sensitivity of less than 1.0 picocoulomb before it is loaded
with the test specimen. The detector amplifier shall have a uniform frequency
response up to 500 kilo{iertz. The following details shall apply:

a. Magnitude of test voltage - 100% service rating


b. Nature of potential . AC tests m be d, properly rated.
-

c. r eu i n scat not be teste with .


C. Du~rartion o arpcation of test voltage - partial discharges shall
be measured for 3 minutes after operating voltage is attained.
Voltage shall be increased from 0 to operating test voltage at
rate of 500 volts per second.
d. Points of application of test voltage - center conductor to shell.
e. Examination after test - connectors shall be visibly examined for
evidence of breakdown, arcing, or other visible damage.
f. Partial discharges shall not exceed the following limits.

Voltage limit Counts/Minute Not to exceed


kV PC/kV over limit PC/kV
DC 1 1 5
AC 2 10 5

187

T ~ . . . . . . 5% '.i.' 5 5~5 . . .

- . - '' -L''• - "- • -


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." - S- - - -
"- - -5• " . . . .
4.6.7 Pulse voltage (see 3.11). Connectors shall be tested with a basic

insulation level voltage (BIL) according to the IEEE-EEI-NEMA Standard Basic ,C


Insulation Levels, NEMA Publication No. 109, dated January 1941 to the value
shown in Table D-11. The BIL shall be in accordance with the following
definition:

"Basic insulation levels are reference level- expressed as pulse crest


voltage with a standard wave not longer than 1.2 x 50 microseconds
(1.2 microseconds rise and 50 microseconds decay, Figure D2). Apparatus
insulation as demonstrated by suitable tests shall have capability equal
to, or greater than, the basic insulation level."

The BIL Levels upon which the connectors shall be tested are 200 percent
rated peak voltage as shown in Table D-11.

188
.. .- . . . . . . . . . . . .. .. . . .
•. ," . ,,• ."-°,°• . . . .. . .. . . . . . . . . . . . . . .
".,. . . '.. .. . ". .. " .
°' .
°-°," . . . .'-•'. ..- •,° °-. . ',' . . '• •
TABLE Dl1: Basic Insulatiun Level Voltages

Voltage Impulse
Rating, Withstand
KV Crest Voltage, KV (Crest)

12.5 25
15 30
25 50
50 100
75 150
100 200
125 250
150 300
. 175 350
200 400
250 500

1.0
0.9
Normalized
Test 0.5
Voltage

0 1.2 50
""rTe - microseconds

Figure D2: Pulse Test Voltage Profile

189
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A.6.8 Vibration.
Complete mated connectors shall be mounted as follows
and subjected to the applicable vibration test. Each receptacle shall be mounted
on a suitable fixture, which, in turn, shall be attached to a vibration table.
A suitable sensor shall monitor the vibration of the receptacle at a point on or
near the receptacle. A counterpart plug shall be engaged with the receptacle and
tightened to torque requirements. The cables shall be clamped to nonvibrating
points at least 8 inches from the rear of the connectors. The clamping length
shall be chosen to avoid resonance of the wire cables.

4.6.8.1 Vibration.
The mated connector shall be mounted as specified in
4.6.8 and vibrated in accordance with method 2005, test condition II of MIL-STD-1344.
The contact shall be wired in .;eries with 100 +10 milliamperes allowed to flow.
A suitable instrument shall be employed to monitor the current flow and to indicate
discontinuity of contact or interruption of current flow (see 3.12).

4.6.9 Shock.

4.6.9.1 Shock.
Mated connectors shall be subjected to approximately 1/2 sine
wave transient shock impulses of 50 gravity units and a duration of 11 +1 milliseconds.
One shock shall be applied in each direction of the three major axes of the connectors.
Receptacles shall be mounted on the shock device or carriage. Plugs shall be engaged
with the receptacles and held by normal locking means only. A current of 100 +_0
milliamperes shall be allowed to flow.

The wire bundles or cables shall be clamped to structures that move with the connectors
A minimum of 8 inches of wire or cable shall be unsupported behind the rear of each
connector. A suitable instrument shall be employed to monitor current flow and to
indicate discontinuity of contact or interruption of current flow (see 3.13).

4.6.10 Humidity. Mated connectors shall be exposed to a relative humidity of


95 +3 percent at a temperature of 71 +20 C for 14 days. Immediately after exposure,
without any forced drying, conduct the dielectric withstanding voltage test of 4.6.5.3.

4.6.11 Contact Resistance. The contact resistance shall be measured in accor-


dance with the contact resistance test of MIL-C-23216 (see 3.15).

4.6.12 Durability. Counterpart solder contact connectors shall be mated and


unmated 500 times at a maximum rate of 600 cycles per hour with the coupling rings
,removed (see 3.16).

190
" *
.lo,
4.6.13 Lorrosio,.
Unmated connectcrs and individual contact samples shall
be tested in accordance with method 1001 of MIL-STD-1344. The following details
"and exceptions shall apply:

a. Test condition letter - B.


b. The samples shall not be mounted but shall be suspended from the top using
waxed twine or string, glass rods or glass cord.

4.6.14 Insulation Resistance.

4.6.14.1 Insulation Resistance at Room Temperature. Unmated connectors shall


be tested in accordance with method 3003 of MIL-STD-1344. The following details
and exceptions shall apply:

a. For lot acceptance testing, where it is undesirable to install actual


contacts in connectors, simulated contacts and special techniques may be
used in performing this test.
b. The tolerance on the applied voltage shall be +10 percent.

4.6.14.2 Insulation Resistance at Room Temperature. Insulation resistance


shall be measured in accordance with 4.6.14.1 between the shell and contact. Simu-
lated contacts may be used (see 3.18.1).

4.6.15 Moisture Resistance. Moisture resistance test specimens shall be sub-


jected to the extreme humidity range (see 4.6.15.1) moisture tests, as applicable.
The connector shall be mated to the counterpart connector. They shall be mounted
horizontally with no drip loops or splices within the chamber. The wires shall
leave the chamber through vaportight seals. Prior to the beginning of the test and
at the end of the test period and while at the high humidity, the insulation resis-
tance between contacts shall be determined as specified in 4.6.14 (see 3.19).

4.6.15.1 Moistuie Resistance, Extreme Humidity Range. Mated solder contact


connectors shall be subjected to the following test. The test chamber shall consist
of a box approximately 12 inches deep by 16 inches wide by 24 inches long, capable
of being sealed, and shall be constructed of materials that, in the presence of
water, will not affect deterioration of the samples. A suitable open screen tray
shall be provided to support the test specimens approximately 8 inches below the
top of the box. Provisions shall be made to bring out wires for measurement purposes
through vaportight seals near the top of the box. Suitable controls shall be provided

191
;2;'t
00.
that will cause the chamber air temperature to vary 5°C (9°F) once each hour for
20 days, from any temperature between 220 and 280 C (720 F and 820 F), causing heavy
condensation to form on the samples once each hour. The bottom of the test chamber
shdll be covered with approximately 1/4 inch of tap water to start the test. The
heat application to supply the temperature variation shall be radiant in nature and
applied to the underside of the test chamber.

4.6.16 Contact Engagement and Separation Forces. Socket contacts shall be


tested in accordance with the contact engagement and separation force test of
MIL-C-23216. Contacts may be tested installed in the connector inserts (see 3.20).
4.6.17 Shell Conductivity. The dc resistance of the wired, mated, assembled
connectors shall be measured from a point on the rear accessory thread of the plug
to the mounting flange of the receptacle. The point of measurement on the receptacle
flange shall be adjacent to the mounting holes on the front or mounting side of the
flange. The dc resistance shall not exceed the values specified in 3.21 when
measured by the voltmeter-ammeter method. The applied potential shall be 1-1/2
volts dc maximum. A resistance shall be inserted in the circuit to limit the current
to 0.100 +.010 amperes. Probes with spherical ends of 0.5 inch minimum radius shall
be used to make the voltage measurements on the connectors. The probes shall not
puncture or otherwise damage the connector finish (see 3.21).

4.6.18 Altitude (see 3.30). Mated connectors shall be tested in accordance


with method 1004 of MIL-STD-i344. The following details shall apply:

a. The connector cable ends shall be located outside the chamber. The cable
ends may be submerged in an insulating liquid or sealed.
b. At the end of the third cycle while the mated connectors are still at
altitude the dielectric withstanding voltage test shall be performed as
specified in 4.6.5.2.
c. Paragraphs 4.4 and 5(e) of method 1004 shall not apply.

4.6.19 Random Vibration tsee 3.;IJ. Wired, mated connectors shall be subjected
to method 214 of MIL-STD-202. The following details shall apply:

a. The connector shall be mounted on the table by normal means.


b. Test condition II - Letter J.
c. The duration of test shall be 8 hours in the longitudinal direction and
8 hours in the perpendicular direction.
d. The contacts shall be wired in a series circuit and 100 to 150 milli-
amperes shall be caused to flew during vibration.
192
5. PACKAGING

"-
:5.1 Packaging Requirements. The packaging requirements for these connectors
shall be in accordance with MIL-C-55J30.

6. NOTES

6.1 irt-nand Use. the connectors covered by this specification are intended
for use in high voltage, high power electrical equipment.

6.1.1 Wire Sizes to be Used with Contacts. It is intended that size 12 wire
be soldered to at least a size 12 contact; and size 6 wire should be soldered to a
size 4 contact because no size b contacts are provided and size 4 is the next
larger, Satisfactory performance of connectors will be obtained if wire sizes are
governed by Tabie D-1.

6.Z Ordering Data. Procurement documents should specify the following:

a. Title, numberand date of this specification.


. b. Style and size of contact.
c. Contact part number with identifying information as to style.
d.. Levels of preservation and packaging,and packing required.
e. Reliability level required.

6.3 qualification. With respect to products requiring qualification, awards


will be made nnly for such products as have, prior to the time set for opening of
bids, been tested and approved for inclusion in the applicable Qualified Products
List whether or not such products have actually been so listed by that date. The
attention of the suppliers is called to this requirement, and manufacturers are
urged to arrange to have the products that they propose to offer to the Federal
Government tested for qualification in order that they may be eligible to be awarded
contracts or orders for the products covered by this specification. The activity
responsible for the qualified products list is Wright-Patterson Air Force Base, Ohio
and information pertaining to qualification of products may be obtained from that
activity.

i93

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" . .".-.'"''""" • " ". ". ..
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6.3.1 Pending establishment of adequate and reliable separated contact quali-
fication standards ana tests an4 in order to insure proper quality and interchange-
ability, sample connectors will be accepted for qualification testing only from the
connector manufacturers who manufactured connectors of this type or style.

NOTICE. When Government drawings, specifications, or other daua are used for
any purpose other than in connection with a definitely related Government pro-
curement operation, the United States Government thereby incurs no responsibility
nor any obligation whatsoever; and the fact that the Government may have formu-
lated, furnishea, or in any way supplied the said drawings, specifications
or oLher daLa is not to be regarded by implication or otherwise as in any
manner licensing the holder or any other person or corporation, or conveying
any rights or permission to manufacture, use, or sell any patented invention
that may in any way be related thereto.

194
•'r

-.4
"*4

S~APPENDIX E

HIGH VOLTAGE CONVERTER "RITERIA DOCUMENT

.4 ,. .. ,. . 9
~W1

HIGH VOLTAGE CONVERTER


CRITERIA DOCUMENT

1. SCOPE

1.1 Scope - This specification covers the general requirements for devices
which convert high power from a 3-phase, alternating-current (ac) generator
or a nominal direct-current (dc) aircraft power source to higher voltage
power.

1.2 C'!assification

1.2.1 Family,
a. Direct Current to Direct Current: Equipment which converts lower voltage

dc power into higher voltage power.


b. A'ternating Current to Direct Current: Equipment which converts alternating
current power into higher voltage power.

1.2.2 Types
a. Regulated: Equipment which converts power supplying a regulated output
voltage and contains provision for parallel operation.
b. Nonregulated: Equipment which converts and supplies power with the
voltage regulation dependent on the inherent characteristics of the
equipment components.

1.2.3 -lasses
a. Class 1: Converters which are liquid-cooled and conform to the altitude-
temperature requirements of MIL-E-5400, Class 1, with the maximum ambient
temperature of 70C.
b. Class 2: Converters which are self-cooled and conform to the altitude-
temperature requirements of MIL-E-5400, Class 1, except that the maximum
0
ambient temperat.,re shall not exceed 85°C.

* 196

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2. APPLICABLE DOCUMENTS

| 2.1 The following documents, of the issue in effect on date of invitation


for bids or request for proposal, form a part of this specification to the
extent specified herein.

SPECIFICATIONS
FEDERAL
L-P-513 - Plastic Sheet, Laminated, Thermosetting, Paper-
Base, Phenolic Resin.
QQ-S-571 - Solder, Tin Alloy; Tin-Lead Alloy; and Lead Alloy.
PPP-B-566 - Boxes, Folding, Paperboard.
PPP-B-601 - Boxes, Wood, Cleated-Plywood.
PPP-B-621 - Boxes, Wood, Nailed and Lock-Corner.
PPP-B-636 - Boxes, Shipping, Fiberboard.
PPP-B-640 - Boxes, Fiberboard, Corrugated, Triple-Wall.
PPP-B-676 - Boxes, Setup.
PPP-T-60 - Tape, Packaging, Waterproof.
PPP-T-76 - Tape, Pressure-Sensitive Adhesive Paper, (for
Carton Sealing).
MILITARY
MIL-I-1O - Insulating Materials, Electrical, Ceramic, Class L.
MIL-M-14 - Molding Plastics and Molded Plastic Parts,
Thermosetting.
MIL-W-76 - Wire and Cable, Hookup, Electrical, Insulated.
MIL-P-116 - Preservation-Packaging, Methods of.
MIL-P-997 - Plastic Material, Laminated, Thermosetting,
Electrical Insulation: Sheets, Glass Cloth, Silicone Resin.
MIL-D-IO00 - Drawings, Engineering and Associated Lists.
MIL-B-5087 - Bonding, Electrical, and Lightning Protection,
for Aerospace Systems.
MIL-E-5400 - Electronic Equipment, Aircraft, General Specification
for

197
MIL-M-7959 Motors ."atingCurrent, 400 Hz, 115/200-
Volts -,u• , Aircraft, Class. A and Class B,
General Specification for.
MIL-F-14256 - Flux, Soldering, Liquid (Rosin Base).
MIL-P-15037 - Plastic Sheet, Laminated, Thernosetting, Class-
Cloth, Melamine-Resin.
MIL-P-15047 - Plastic-Material, Laminated Thermosetting, Sheets,
Nylon Fabric Base, Phenolic-Resin.
MIL-W-16876 - Wire, Electrical, Insulated, High Temperature.
MIL-P-18177 - Plastic Sheet, Laminated, Thermosetting, Glass
Fiber-Base, Epoxy Resin.
MIL-C-45662 - Calibration System Requirements.

STANDARDS
MILITARY
MIL-STD-129 - Marking for Shipment and Storage.
MIL-STD-147 - Palletized Unit Loads on 40" x 48" Pallets.
MIL-STD-202 - Test Methods for Electronic and Electrical Component
Parts.
MIL-STD-446 - Environmental Requirements for Electronic Component
Parts
MIL-STD-454 - Standard, General Requirements for Electronic

Equipment.
MIL-STD-461 - Electromagnetic Interference Characteristics
Requirements for Equipment.
MIL-STD-462 - Electromagnetic Interference Characteristics,
Measurement of.
MIL-STD-831 - Test Reports, Preparation of
MIL-STD-810 - Environmental Test Methods.
MIL-STD-1285- Marking of Electrical and Electronic Parts.
MIL-STD-1543- Test Requirements for Space Vehicles.

198
Np '-\ ' \-,..".'. ." - •. .i.•.. .. 1 -'-' . •• • .. - .
. .. MS33586 - Metals, Definition of Dissimilar

(Copies of specifications, standards, drawings, and publications required by


suppliers in connection with specific procurement functions should be obtained
from the procuring activity or as directed by the contracting officer.)

2.2 Other publications. The following documents form a part of this


specification to the extent specified herein. Unless otherwise indicated, the
issue in effect on date of invitation for bids or request for proposal shall
apply.

NEMA Publication No. 109 - IEEE-EEI-NEMA Standard Basic Insulation


Level.
ASTM-D 1868 - Detection and Measurement of Discharge
(Corona) Pulses in Evaluation of Insulation
Systems.
ASTM-D 3382-75 - Measurement of Energy and Integrated
Charge Transfer Due to Partial Discharges
(Corona) Using Bridge Techniques.
ASTM-D 3426 - Dielectric Breakdown Voltage and
Dielectric Strength of Solid Electrical
Insulating Materials Using Impulse Waves.

American National Standard - C57.12.00-1973 - General Requirements for


Distribution, Power, and Regulating
Transformers.
Appendix A - High Voltage Cable Criteria Document.
Appendix C - High Voltage Capacitor Criteria Document.
Appendix F - Aircraft high Voltage Electric Power
Characteristics Criteria Document
AFW9L-TR-82-2057, Vol. 4 - H~igh Voltage Design Guide: Aircraft

MIL-HDBK-251 - Military Handbook, Reliability/De;ign


Thermal Applications, 19 January 1978.

199
.*
r.70 ! -. ". ,.. T -' , • ,I .' '.x ., "

NATIONAL BUREAU OF STANDARDS

Handbook H28 - Screw-Thread Standards for Federal


Services

(Application for copies should be addressed to the Superintendent of


Documents, Government Printing Office, Washington, D.C., 20402.)

INSTITUTE OF ELECTRIC AND ELECTRONIC ENGINEERS

IEEE STD-4 IEEE Standard Techniques for High Voltage Testing


IEEE STD 28-1975 Surge Arresters for Alternating Current Power Circuits

.20

'oB

200

.,.•
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3. REQUIREMENTS

3.1 Qualification - The converter furnished under this specification shall


be a product which has been tested and has passed the qualification tests
specified herein, and has been listed on or approved for listing on the appli-
cable Qualified Products List. When there are no products listed or approved
for listing on the Qualified Products List, the qualification requirement
is waived only by the preparing activity; and procuring activities shall
involve first article inspection.

3.2 Specification sheets - The individual equipment requirement shall be


Q specified herein and in accordance with the applicable detail specification
sheets. Whenever the requirements of this specification and the detail spe-
cification or standard conflict, the requirements of the detail specification
or standard shall govern. Any deviation from this specification or from
subsidiary specifications or standards, W.1te:re applicable, must be specifically
approved in writing by the procuring activity.

3.2.1 First article - Power converters not covered by specification sheets


shall be as specified in an applicable complementary document. These products
shall have been tested and passed the inspection in 4.6 and 6.3. This inspec-
tion consists of meeting all of the qualification tests of 4.8 through 4.12,
inclu.Szlve.

3.2.2 Information to be furnished with first article sample - The applicable


information outlined in 6.2 shall be furnished with the first a.,ticle sample,
togeter with any other pertinent information as required by the Government.

3.3 Materials, parts, and processes

3.3.1 Selection of materials, parts, and processes - Materials, pirts, and


processes shall conform to applicable Government specifications. Materials
conforming to contractor's specifications may be used provided the specifications
are approved by the Government and contain provisions for adequate tests. The
use of contractor's specifications will not constitute weiver of Government
inspection.

201

•.• •,• • -• •,. ,• t-'•. .•,, _ o , " "° . ..- .. " .'- -' " o - - ' -'. .-. ..- . -. . -. .,.-'. . , •
3.3.1.1 Substitution of materials - If the supplier desires to substitute
another material for a specified material or fabricated part, he shall submit
a statement to the Government describing the proposed svbstitution, together
with evidence to substantiate his claims that such substitute is suitable.
At the discretion of the Government, test samples may be required to prove
the suitabili t y of the proposed substitute. Before such substitutions are
made, approval for each substitution shall be obtained in writing from the
Government.

3.3.1.2 Flammable materials - Insofar as practicable, materials used in the


construction of the power converter shall be nonflanujiable and nonexplosive.

3.3.1.3 Corrosive materials - Corrosive materials used in any of the manu-


facturing processes shall be removed or neutralized so that no corrosion will
result from such use. Insofar as practicable, materials used in the con-
struction of power converters shall be noncorrosive.

3.3.2 Electrical insulati-g materials - Electrical insulating materials used,


including plastics, fabrics, and protective finishes, shall be moisture resistant
and shall not support fungus growth. The nonmetals shall not support combustion
and shall not be adversely affected by weather, aircraft fluids, temperatures,
and ambient conditions encountered during operation of the aircraft. Nonmetals
may be treated to conform to this requirement.

3.3.2.1 Laminated phenolic - Laminated phenolic materials shall conform to


MIL-P-997, L-P-513, MIL-P-15037, or MIL-P-15047. When electrical characteristics
are involved, only natural uncolored ijate•-.als shall be used.

3.3.2.2 Molded phenolic or melamine - Molded phenolic or melamine materials


shall conform to MIL-M-14.

3.3.2.3 Ceramic (external use) - Ceramic .materials shall conform to MIL-I-lO.

3.3.2.4 Laminated plastic sheet - Liiinated plastic sheet, epoxy, shall conform
to MIL-P-18177.

202

-".. . .
.-. ,;.s.'
3.3.2.5 Materials quality- Molded, ceramic and laminated materials shall be
free of flaws such as cracks, delaminations and voids. Sample lots shall be
evaluated to assure flaws do not exist in the virgin material or processed
materials. Bolting and clamping shall be designed to prevent delamination or
cracking of large,thick,laminated and molded parts during installation of
parts and wiring.

3.3.3 Metals - The metal materials for each part shall be as specified (see
3.2). When a definite metal is not specified, a metal which will enable the
part to meet the require•ients of this specification shall be used. Acceptance
or approval of a constituent material shall not be construed as a guarantee of
the acceptance of the finished product.

3.3.3.1 Corrosion resistance - Materials shall be of a corrosion-resisting


type or suitably processed to resist corrosion. Any corrosion that causes
malfunctioning of the equipment, shortening of life, impairment of use, or
impairment of ease of replacement of parts shall be cause for rejection.

* 3.3.3.2 Dissimilar metals - Dissimilar metals, as defined by Standard MS33586,


when used in contact with each other, shall be protected against electrolytic
corrosion, and shall have a low-impedance path to radio-frequency currents as
specified in requirement 16 of MIL-STD-454.

3.3.3.3 Solder and soldering Flux - Solder, when used, shall be in accordance
with QQ-S-571. Soldering flux shall be in accordance with MIL-F-14256.

3.3.3.4 Screws, nuts, bolts, and washers - All mounting and terminal screws,
nuts, bolts, and washers shall be of corrosion-resistant material or shall be
protected against corrosion.

3.3.3.5 Corona protection - All mounting and terminal screws, nuts, bolts,
and washers near a high voltage part shall have rounded configuration to
eliminate probability of corona. Screw threads shall not exist in parts
subjected to hIgh field concentration.

3203
.1- ,n -,- '- • ". • .; - • . " . ' ' ' ' .:,.-.-.-...-' ." . . ."-" . "-"-"•. . . . ... ' .- , .-...- -.-. •
3.3.4 Toxic materials - Materials which are known to produce harmful toxic
effects under any conditions, including fire, shall not be incorporated in
the design without prior approval of the procuring activity.

3.3.5 Standard parts - Standard parts shall be used wherever they are suitable
for the purpose, and shall be identified on the drawings by their standard
part number. In the event there is no suitable standard part in effect on
the date of invitation for bids, commercial parts may be used provided they
conform to this specification and can meet the same parts screening procedure
as for standard parts.

3.3.6 Nonstandard parts and materials - A request for the use of nonstandard
parts and materials shall be submitted to the procuring activity for approval
prior to their use in the design and construction of the equipment.

3.3.7 Interchangeability - All parts having the same manufacturer's part


number shall be directly and completely interchangeable with respect to in-
stallation and performance. Changes in manufacturer's part numbers shall
be governed by the drawing number requirements of MIL-D-IO00.

3.3.8 Wire - Internal wiring of a power converter is considered to be all the


interconnecting wiring beyond the point where the power enters the copverter
enclGsure and processed power leaves the converter enclosure.

3.3.8.1 Insulated wire - When insulated wires are used in wire terminals, the
wire shall be of the types and sizes covered in MIL-W-76, MIL-W-16878 or the
H.V. cable criteria document. Government approval shall be required when
other types and sizes of insulated wires are used as terminals.

3.3.8.2 Wire support - All wires, cables, and buses shall be supported and
arranged so that they will withstand abrasion, flexing, and vibration. Clamping
shall be such that it will not damage the insulation.

3.4 Design and construction - The article shall conform to the applicable
specifications and standards or to the detailed specifications (see 3.2).

204
I .. .. . S. *• -: . ..:...-........ ......
3.4.1 Functional description - The power converter shall provide high voltage
, -..•. power to a selected aircraft load upon demandwithout arcing, during ground
testing and flight operation. Input power to the power converter shall be
either from the aircraft power source or an equivalent ground power unit.

3.4.2 Performance

3.4.2.1 Input voltage - The nominal input voltage to the power converter shall
be from an alternating current power source or a magnetohydrodynamic (MHD)
direct current power source.

3.4.2.2 Alternating current power source - The input voltage from an alternating
current power source shall meet the detailed requirements defined in the High
Voltage Electric Power Characteristic Criteria Document (Appendix F), see Figures
El and E2.

3.4.2.2.1 Power factor - The input power factor shall be no less than 80
percent over the input frequency and voltage range under full load conditions.
The reactive power for any load conditions less than full load shall not be
more than that measured at full rated output.

3.4.2.2.2 Input current balance - From 25 percent to rated load conditions,


the current in eachphaseshall be within 5 percent of the average value of the
currents in all phases.

3.4.2.2.3 Reduced input frequency - Units shall not be damaged and shall
supply full load current with the output voltage remaining between +20
percent nominal rated volts when the input fr'equency is increased or reduced
20 percent for 15 seconds.

* 3.4.2.3 MHD power source - The input power from a MHD power source shall be
a nominal 5000 volts dc which meets the detailed requirements defined in Figure E3.

3.4.2.4 Input voltage transient - The power converter shall be capable of


, *.. withstanding, without damage, the input voltage transients from the respective

205
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206
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208
- a-.... *.' . *.,., . . . a a **. . . - . a . a **. a - a* - a a * a
a- a .* .*. .. a a
power source as defined in Figure E2 (Envelope of AC Voltage Transient) and
Figure E-4 (Envelope of DC Voltage Transient) for a dc power source.

3.4.2.5 Output voltage - The steady-state output voltage of the article shall not
vary more than +10% from no load to full-load over the input voltage range as specified in
paragraphs 3.4.2.2 and 3.4.2.3.

3.4.2.6 Output voltage transients - With an input variation as specified in


paragraphs 3.4.2.2 and 3.4.2.3, the output voltage shall remain within the limits of Figure
E4 (Envelope of DC Voltage Transient).

3.4.2.7 Ripple and modulation - The output voltage ripple and/or modulation shall
not exceed 2 percem rms. The output distortion and spectrum shall nol exce^.d the limits
shown in Figure ES.

3.4.2.8 Rated load - The article shall be capable of delivering continuous, full-load
power, uninterrupted, as specified in the detailed specification sheet, when cooled per
paragraph 3.4.2.11.

3.4.2.9 Short circuit capability - The article shall be capable of withstanding a short
circuit condition for a period of 3 seconds without deamage. After removal of the short
circuit condition, the article shall be capable of supplyirg rated load for the remainder of
the operating period, and not exhibit any performance degradation. The short circuit
current shall be limited to 750 percent rated current, minimum.

3.4,2.10 Overload - The unit shall be capable of delivering 200 percent rated
current for I minute and 150 percent rated current for 2 minutes with voltage output
variation less than +20 percent.

3.4.2.11 Efficiency - The efficiency of the article at rated output shall not be less

'. • percent for ar alternating current source.


b. 835 percent for a direct cu,' ent source.

." 209
MAXIMUM LIMIT

*100

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a 10 is 20 25 30 36

TIME FROM ONSET OF TRANSIENT. SECONDS

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-

3.4.2.12 Signal processor - The signal processor shall be st 'ied with a


low radio frequency impedance path to ground and across all neeL,....,foal discon-
tinuities. The processor shall operate following impulse spikes generated
by partial discharges, momentary short cirtuits, and starting transients within
the power converter electrical circuits. All signal processor inputs which
are not normally connected externally to the high voltage input or output
lines shall be designed with a sufficiently low impedance path to ground to
protect the signal processor circuits.

3.4.2.13 Reflected transients - Transient or ripple currents refle'ted to


the input power lines shall be in accordance with the detailed specification.

3.4.2.14 Isolation - The output power lines shall be electrically isolated


* from the input power lines.

3.4.2.15 Remote sensing - The article shall have provisions for remote voltage
sensing. The article shall maintain the voltage regulation requirements of
3.4.2.5 when subjected to voltage drorl in the output lines between the article
and the remote sense point as specified in the detailed specification.

3.4.3 Operational conditions - The article shall be designed to provide rated


output under the following conditions or natural combination thereof, listed
in the following subparagraphs.

3.4.3.1 Temperature and altitude - The power converter shall meet the require-
ments of Paragraph 3.4.2 when subjected to the following ambient temperature
range:
a. Operating - The equipment shall be capable of operating at temperatures
between -20°C to 550 C at pressure altitudes from 1,000 feet below sea level to
40,,1300 feet above sea level. It shall be capable of operating for one five-
minute cycle in an ambient temperature from -55 0 C to 71°C at altitudes 1,000
feet below sea level to 40,000 feet above sea level. It shall be capable of
withstanding a pressure drop from 15,000 feet altitude to 45,00n feet altitude
in 15 seconds while operating.

212
b. Non-operating - The equipment shall be capable of continuous exposure to
ambient temperatures from -55°C to +71°C at pressure altitudes from 1,000 feet
below sea level to 40,000 feet above sea level.
c. ycling - The converter shall be capable of two coerating cycles at full
load as specified in the detailed specification sheets (3.2).

3.4.3.2 Humidity - The equipment shall be capable of operating at relative


humidity ranging up to 100 percent, including conditions where condensation
will take place on the equipment as specified in 4.9.3.

3.4.3.3 Sand and dust - The equipment shall be capable of operating under
conditions of airborne sand and dust particles as specified in 4.9.4.

3.4.3.4 Salt spray - The equipment shall be capable of operating in an


atmosphere containing salt-laden moisture as specified in 4.9.5.

3.4.3.5 Fungus - The equipment shall be capable of operating when exposed


to fungi as encountered in tropical areas as specified in 4.9.6.

3.4.3.6 Shock - The article shall be free of leaks, cracks, bursting, or


bulging of the cases when tested as specified in 4.9.7.

3.4.3.7 Vibration - When the article is tested as specified in 4.9.8, there


shall be no leakage of filling materials and no evidence of other physical
damage such as cracks, bursting, or bulging of the case.

3.4.3.8 Flammability - When the article is tested as specified 'n 4.9.9,


there shall be no evidence of violent burning which results in an explosive-
type fire, and the coating material used on the article shall be self-extin-
guishing. The article shall not be considered to have failed, in the event
that it is consumed by thc applied flame, unless dripping of flaming material
or an explosive-type flame has occurred. The article shall be considered to
have failed only if an explosion or dripping of flaming material occurs, an
explosive-type flame is produced, or if visible burning continues for more than the
allowable duration of 3 minutes after removal of the applied flame. Material
will be considered self-extinguishing if the following conditions are met:
a. The duration of visible flame. does not exceed 3 minutes after removal
of the applied flame.

213

,•..:
,... *+.
,-.. . . .
,... * . . .. . ..
.,.- .
. .. . "..,. . *.
*..,.* . .*
,. -. , ,... ~.**-
. :* ,-.
.
.- ..- ** , .. *
.-.* ..,, . .. ' . *.. ... , -, . *....,...., . -
b. There is no explosion, nor any violent burning which results in an
explosive-type flame.
c. There is no dripping of flaming material frcm the converter
under test.

3.4.3.9 Nuclear radiation - Exposure limits to nuclear radiation shall be


specified in the detailed specification.

3.4.4 Mechanical construction

3.4.4.1 Seal

3.4.4.1.1 Liquid-filled units


When the article is tested as specified in
-

4.10.2.1, there shall be no evidence of liquid leakage.

3.4.4.1.2 Gas-filled units - When the article is tested as specified in


4.10.2.2, the leak rate shall riot exceed xlO- 8 standard atmosphere cubic
centimeter per second (attn cm3 /s).

3.4.4.1.3 Pressure-vacuum transducer - A pressure-vacuum transducer shall oe


furnished for sealed-tank and gas-oil-seal construction.

3.4.4.1.4 Liquid temperature transducer - A liquid temperature transducer


shall be furnished for sealed tank liquid filled construction.

3.4.4.1.5 Pressure-vacuum bleeder - A pressure-vacuum bleeder device shall be


set to operate at the maximum operating pressure (positive and negative) irn-
dicated on the nameplate. Effluent gases/liquis shall be ported overboard from
the aircraft.

3.4.4.1.6 Tanks - Tanks shall be designed for vacuum filling in the field. A
pressure relief device shall be provided on the cover. Maximum operating pres-
sures (positive and negative) for which the converter is to be operated
shall be indicated on the nameplate.

214

- .
3.4.4.2 Cooling - The article external cooling shall be from the aircraft
- ethylene-glycol-water liquid loop. The article shall receive coolant condi-
tionin• from the airplane system, as specified in the detailed specification
sheet (see 3.2). Sensors shall be installed within the article to thermally
control the article during storage, standby,and operation.

3.4.4.3 Fans, pumps, and control - The equipment for automatic control oF fans
or pumps for forced-Air-cooled or liquid-cooled articles shall be thermally
controlled with a ,ianual override switch in parallel with the automatic control.
Contacts and sensors shall be enclosed inside the sealed tank. Fan motors
shall conform to MIL.M-7969.

3.4.4.4 Lifting, moviqg, and jacking facilities

3.4.4.4.1 Safety factor - Lifting, moving, and jacking facilities shall be


designed to provide a safety factor of 5. This safety factor is the ratio
of the ultimate stress of the material used to the working stress. The working
stress is the maximum combined stress developed in the lifting facilities
by the static load of the component being lifted.

3.4.-i.4.2 Lifting facilities - Lifting facilities shall be provided for lifting


the cover separately, and also for lifting the internal assembly from the
housing using four lifting cables.

Facilities for lifti-nn the complete article (with the cover securely fastened
in place) shall be provided. Lifting facilities shall be designed for lifting
with four slings at a maximum angle of 30 degrees with respect to the vertical
The bearing surfaces of the lifting facilities shall be free frim sharp edges
and shall be provided with a hole having a minimum diameter o' 13/16 inch
(20.6 mm) for guying purposes.

3.4.4.4.3 Moving facilities - The base of the article shall be of heavy plate
or shall have members forming a rectangle that will permit rolling in the
directions of the centerlines of the segments.

3.4.4.4.4 Jacking facilities - Jacking facilities shall be located near the


extreme ends of the junctions of the case.

215

WO.................................................. '_..''.'"-.. -... ,-..,,. "..


-ii

3.4.4.4.5 Mounting - The points of support shall be so that the unit will
withstand the variable orientation of the airplane.

3.4.4.4.6 Mounting studs - When specified (see 3.2), external mounting studs
shall be provided with a flat washer and locknut, or with a flat washer,
loekwasher, and a nut.

3.4.4.5 Mounting and terminal screws and mounting inserts - Screw threads
shall be class 2A or 2B, as applicable (see 3.2), in accordance with Handbook
H28. Exterrnal screw threads, class 2 fit, shall, after receiving a finish,
be capable of accepting a nut of class 2B fit and internal screw threads,
class 2 fit, shall, after receiving a finish, be capable of accepting a screw
of class 2A fit. Maximum installation torque shall be as specified in the
detailed specification. Nuts shall run down to within two threads of mounting
surfaces.

3.4.4.6 Screw terminals - When specified (see 3.2), external screw terminals
shall be supplied with two nuts, two flat washers, and one lockwasher. For
cased units, the height of the terminal assembly shall be the distance from
the free end of the screw to the terminal mounting surface. The type of
terminal, size of screw threrd, and the exposed length of threads +0.062
inch shall be as specified (e.g., screw, 0.164-32 UNC x 0.375) (see 3.2).

3.4.4.7 Terminal strength - When the article is tested as specified in 4.10.5,


there shall be no evidence of loosening or rupturing of the terminals, or other
mechanical damage. Bends shall not be considered as damaged unless surface
cracking is evident. Except for flexible leads, there shall be no rotation of
the terminals. Rotation of the external portion of the metallic portion of
a "hook" type terminal exceeding 10 degrees shall not constilute a failure.

3.4.5 Electrical construction

3.4.5.1 Internal wire leads - Internal wire leads shall be attached to the
internal component terminals or case by soldering, welding, brazing, or other
method (e.g., lead-sh.ating or nylon-coated wires) in such a manner as to

216
•,• . . . . . . . . ... . . .. o . . ..-.-
pru6;de adequate electrical connection and mechanical strength. Where soft
solder is used to provide the electrical conncction, wire leads shall be
anchored mechanically.

3.4.5.2 Wire bundle ties and clamps - Wire bundle ties shall have the knots
either burnished or enameled. (See"High Voltage Design Guide: Aircraft").

- 3.4.5.3 Terminals

3.4.5.3.1 Solder terminals (see 4.10.5.1.2) - Solder terminals may be of any


shape and shall be capable of complying with solderability requirements of this
specification. The height of the solder terminal shall be considered as the
maximum distance from the terminal mounting surface to the highest point,
including the additional height obtained if semiflexible terminals are
straightened. (It is not intended that the "hook" in the hook-type terminal
be straightened from its normal hooked position). The type of terminal and
the maximum size of wire which the terminal will accept externally shall be
Mr as specified (see 3.2).

3.4.5.3.2 Case as terminal - When the case is used as a terminal, any pro-
tective coating applied to the mounting surfaces shall be such as to provide
a direct conducting path for an electric current from the case to the surface
on which it is movnted.

3.4.5.3.3 Bush'ngs - The insulation level of line bushings shall be equal


to or greater thaA the insulation level of the windings to which they are
connected.

3.4.5.3.4 Terminal insulators - Terminal insulators shall be epoxy, glass,


or ceramic.

3.4.5.3.5 Connectors - Connectors shall be hermetically sealed, circular


threaded, high voltage with solder or brazed contacts.

217
3.4.5.4 Corona protected bushing insulator - When specified (see 3.2), ter-
minals shall be supplied with a corona suppressor where the terminal and
terminal hardware are shielded by an angle of at least 30 degrees by a corona
suppressor cavity. Terminal hardware shall consist of two nuts, one flat
washer, and one lockwasher, or shall consist of one flat washer, one lockwasher,
and one cap screw. The terminal post shall not have external threads below
the corona suppressor in the bushing. Terminal post finish shall be 100
microns or smoother. The height of the terminal assembly shall be the distance
from the top of the corona suppressor to the terminal mounting surface. The
type of terminal shall be specified (see 3.2).

3.4.5.5 Solderability - When the article is tested as Fpecified in 4.10.7,


it shall meet the applicable criteria for terminal evaluation in the test
method.

3.4.5.6 Resistance to soldering heat - When the article is tested as specified


in 4.10.8, there shall be no softening of the insulation or loosening of the
windings or terminals.

3.4.5.7 Potting, filling, or encapsulating material - The amount and coverage


of potting, filling, or encapsulating material used shall be essentially the
same for all units of a specific design. Potting, filling, or encapsulating
material shall not flow from the case of the article during any of the appli-
cable tests.

3.4.5.8 Grounding - The article shall be grounded by bonding the case(s)


to the airplane structure. A common point ground shall be specified for
bonding the power source and load in a manner to prevent circulating currents
in the ground path, protect the equipment from electromagnetic pulses and
lightning, reduce electromagnetic interference, and prevent electrostatic
discharges harmful to personnel. A ground path shall provide a path with
a current-carrying capacity equal to or greater than that of the input and
output conductors.

218
:-.- ....-."-.--..
/•-,,,,-',',,~~~~~~~..
,-,. -..-. -.... '... -. ..'.-.-.- ..-. ..- ..- . .- ' .. . .. " .. -" ". - .- ". * """" '
U' 3.4.5.9 Capacitor - The dielectric strength of the high voltage capaci-
.5.t ,.•.. tors shall be as specified in the "High Voltage Capacitor Criteria Document

3.4.5.10 Surge arresters - When specified, a surge arrestor ground


pod consisting of a tank ground pod, mounted near the high voltage terminals
shall be available for surge protection.

3.5 High voltage design and test

3.5.1 Insulation resistance - When measured as specified in 4.11.1,


the minimum insulation resistance shall be great,'r than the value specified
for the insulation system in the applicable specification.

3.5.2 Dielectric withstanding voltage -. When tested as specified in


4.11.2, there shall be no evidence of arcing, flashover, breakdown of insula-
tion, or damage.

3.5.3 Partial discharges (when specified, see 3.2) - When tested as


outlined in 4.8.13 or as specified (see 3.2), the partial discharge maximum
magnitudes shall not exceed 5 PC/kV picocoulombs (peak) at rated voltage.

3.5.4 Pulse - When tested as outlined in 4.11.4 or as specified (see


3.2), pulse voltages shall have a wave shape as defined in 4.11.4.5. 'Pulse tests
shall be made without excitation.

3.5.4.1 Terminals not being tested - inputs to low voltage instrumentation


and control equipment shall be grounded during pulse tests.

219
. . -R. .
• ' •"',";"
•, ,% •;,. ',-",••," ?••z"•7
.,"•°• "o". ',,.•,• ''*..,,' ...- % -' ... '."• . " .". " "". .. ' ., • " . '
4. QUALITY ASSURANCE PROVISIONS

4.1 Responsibility for inspection - Unless otherwise specified in the con-


tract or purchase order, the supplier is responsible for the performance of
all inspection requirements as specified herein. Except as otherwise speci-
fied in the contract or order, the supplier may use his own or any other
facilities suitable for the performance of the inspection requirements speci-
fied herein, unless disapproved by the Government. The Government reserves
the right to perform any of the inspections set forth in the specification
where such inspections are deemed necessary to assure supplies and services
conform to prescribed requirements.

4.1.1 Test equipment and inspection facilities - Test and measuring equip-
ment and inspection facilities of sufficient accuracy, quality, and quantity
to permit performance of the required inspection shall be established and
maintained by the inspection facility. The establishment and maintenance
of a calibration system to control the accuracy of the measuring and test
equipment shall be in accordance with MIL-C-45662.

4.2 Classification of inspection - The inspections specified herein are


classified as follows:
a. Materials inspection (see 4.3).
b. Qualification inspection (see 4.5).
c. Quality conformance inspection (see 4.6).

4.3 Materials inspection - Materials inspection shall consist of certi-


fication supported by verifying data that the materials listed in table El
used in fabricating the power converter, are in accordance with the appli-
cable referenced specifications or requirements prior to such fabrication.

.4I•

"220

................ ........ ...


,':"0..,TABLE El. Materials Inspection

REQUIREMENT
MATERIALS PARAGRAPH APPLICABLE SPECIFICATION
Insulating
Laminated material:
phenolic - - - 3.3.2.1 MIL-P-997, L-P-S13,
MIL-P-15037, or MIL-P-15047
Molded phenolic or
melamine - 3.3.2.2 MIL-M-14
Ceramic (external use) - 3.3.2.3 MIL-I-IO
Laminated Plastic Sheet -3.3.2.4 MIL-P-18]77
Wire:
Insulated wire -3.3.8.1 MIL-W-76 or MIL-W-16878
Wire supports 3.3.8.2 High Voltage Cable Assembly
Criteria Document, Appendix B

4.4 Inspection conditions Unless otherwise specifie6 herein, all inspec-

tions shall be performed in accordance with the test conditions specified


in the "GENERAL REQUIREMENTS" of MIL-STD-202, MIL-STD-454 and MIL-E-5400.

... 4.4.1 Test frequency - When an ac power source frequency is specified herein,
the frequency used shall be within +2 percent of the nominal value. The

test frequency shall be the geometric mean of the specified frequency range
or a lower value selected by the manufacturer.

4.4.2 Test voltage - When the rated input voltages are specified with a
tolerance (see 3.2), the test voltage shall be the rated voltage (e.g.,
P00 + 10 volts shall be tested at 5p.O volts). For dielectric withstanding
voltage tests, the peak of the voltage applied shall not exceed by more
than 5 percent the peak of the pure sine voltage.

4.5 Qualification inspection - Qualification inspection shall be performed


tetreuec
sal b hegemeri ea o tespciie feuecyrag
at a laboratory acceptable to the Government (see c.3)
on a sample unit pro-
duced with equipment and procedures normally used in production.
"4.5.1 Sample size A sample of one unit shall be comprised of a power
-

converter and shall be submitted for inspection.

4.5.2 Inspection routine - The sample unit shall be subjected to the inspec-
tions specified in Table E2 in the order shown.

4.5.3 Failure - One or more failures of the specified qualification


inspection tests listed in Table E2 shall be cause for refusal to grant
qualification approval.

4.5.4 Test reports - Samples shall be accompanied with certified test


reports in accordance with MIL-STD-831, including a statement that the
samples have been subjected to the tests and comply with this specifica-
tion. Photographs of oscilloscope of ripple voltage shall be submitted
(see 4.8.2.1). Samples shall also be accompanied with two copies of
outline and detail assembly drawings thereof and two copies of sample
instructions with illustrations and diagrams, if necessary, covering
the installation of the converter.

4.5.5 .Rejection and retest of qualification and quality conformance units -


Units which have been rejected or returned to the manufacturer for any
reason during qualification or quality conformance tests may be reworked
or have parts replaced to correct defects. Before resubmitting the unit,
full particulars concerning the rejection and corrective action taken by
the manufacturer must be submitted in writing by the manufacturer to the
test activity and to the procuring activity. Tests shall not be resumed
until such a report is received. Where qualification tests are conducted
under the auspices of the manufacturer, the procuring activity shall be
advised upon failure of a qualification sample and of the action taken
by the manufacturer with regard to the failure.

4.5.6 Retention of qualification - To retain qualification, the supplier


shall meet the requirements of 4.5.2 every 36 months. The qualifying
activity shall be notified in advance before action is initiated for

Z222

• ,b.t . '.. *..~t...


...-.. .-.. ...- ......- .....-... ...... .. * - 9. ...
Table E2. Qualification Inspection

REQUIREM-NT METHOD
EXAMINATION OR TEST PARAGRAPH PARAGRAPH

Visual and mechanical examinationi 3.1, 3.4.4.4 to 4.7.1


3.4.5.3inc,
3.4.5.3.5, 3.4.5.4,
3.4.5.7, 3.7,
3.8 and 3.9
Input voltage 3.4.2.1,3.4.2.2 4.7.1, 4.8.2,
Power Factor 3.4.2.2.1 4.8.2.3
Input current balance 3.4.2.2.2 4.8.2.5
Reduced input frequency 3.4.2.2.3 4.8.2
Input voltage transient 3.4.2.4 4.8.3.1
Output voltage 3.4.2.5 4.8.2
Output voltage transient 3.4.2.6 4.8.3.1
Ripple and modulation 3.4.2.7 4.8.2.1
Rated load 3.4.2.8 4.8.2
Short circuit capability 3.4.2.9 4.8.3.2
Overload 3.4.2.10 4.8.3.3
Efficiency 3.4.2.11 4.8.2.4
Signal processor 3.4.2.12 4.8.4
Reflected transients 3.4.2.13 4,8.5
Isolation ?.4.2.14 4.8.6
Remote Sensing 3.4.2.15 4.8.7
Temperature and altitude 3.4.3.1 4.9.1 & 4.9.2
Humidity 3.4.3.2 4.9.3
Sand 401d dust 3.4.3.3 4.9.4
Salt spray 3.4.3.4 4.9.5
Fungus 3.4.3.5 4.9.6
Shock 3.4.3.6 4.9.7
Vibration 3.4.3.7 4.9.8
Flammability 3.4.3.8 4.9.9
Nuclear radiation 3.4.3.9 4.9.10
Seals 3.4.4.1 4.10.1
Pressure-vacuum transducer 3.4.4.1.3 4.10.2.1
Liquid temperature transducer 3.4.4.1.4 4,10.2.1
Pressure-vacuum bleeder 3.4.4.1.5 4.10.2.2
(Continued)

:4 *
Table E2. Qualification Inspection (Continued)

EXAMINATION OR TEST REQUIREMENT METHOD


PARAGRAPH PARAGRAPH

Tanks 3.4.4.1.6 4.10.3


Cooling 3.4.4.2 4.10.4
Fans, pumps and motor 3.4.4.3 4.10.2.3
Terminals 3.4.5.3 4.10.5
Bushings 3.4.5.3.3 4.10..76
Solderability 3.4.5.5 4.10.7
Resistance to soldering heat 3.4.5.6 4.10.8
Grounding 3.4.5.8 4.10.9
Capacitors 3.4.5.9 4.10.10
Surge arrastors 3.4.5.10 4.10.11
Insulation resistance 3.5.1 4.11.1
Dielectric withstanding voltage 3.5.2 4.11.2
Partial discharges 3.5.3 4.11.3
Pulse 3.5.4 4.11.4
Electromagnetic compatibilIty 3.5.5 4.11.5
Life 3.6 4.12

9-.7

"t4

S2.

:.2.
¾..
) - -... ' • ' ''' i ' • . - ". - • • ' ' _•• '.' . . . .• " ".. _ - " o ''' ' ' _ , • ' '" , ' ' , " , , - .
retention of qualification. The test samples shall be selected from items
produced within a previous 6-months production period. However, if this
production period cannot be met, the qualifying activity shall determine
which items are to be selected for qualification inspection. The supplier
shall also forward at 12-months intervals to the qualifying activity a
summary of the results of the tests performed for inspection of product
for delivery, groups A and B, indicating as a minimum the number of lots
that have passed and the number that failed. The results of tests of all
reworked lots shall be identified and accounted for.

4.6 Quality conformance inspection

4.6.1 Inspection of product for delivery - Inspection of the product for


delivery shall consist of the inspections and tests specified in Table E3.
All deliverable high voltage, high power convertersshall be subjected to
the inspections specified in Table E3.

4.6.1.1 Inspection lot - Inspection shall be for a completely assembled


converter of the same family, type, and class having similar electrical
characteristics, manufactured under essentially the same conditions, and
having similar construction and materials. (Similar construction and
materials shall be construed to include differences that will not affect
test results).

4.6.1.2 Rejected lots - If an inspection article is rejected, the supplier


may rework it to correct the defects, or screen out the defective com-
ponents &nd resubmit for reinspection. Resubmitted lots shall be inspected
using tightened inspection. Such articles shall be separate from new
articles and shall be clearly identified as reinspected articles.

4.6.1.3 Disposition of units - Units which have passed inspection may be


delivered on the contract or purchase order, if the units are accepted and
are still within specified electrical tolerances, ind if the terminals of
the sample units are clean and smooth.

"4.-"

225
Table E3. Quality Conformance Inspection

Requirement Method
Examination Paragraph Paragraph
Visual and mechanical examination 3.1, 3.4.4.1 4.7.1.1 and
to 3.4.4.1.5 -0.7.1.3
incl., 3.4.4.2
to 3.4.5.8, incl.,
3.4.5.9, 3.7,
3.8 and 3.9
Input voltage 3.4.2.1 or 4.8.2
3.4.2.2
Power factor 3.4.2.2.1 4.8.2.3
Input current balance 3.4.2.2.2 4.8.2.5
Output voltage 3.4.2,5 4.8.2
Ripple and modulation 3.4.2.7 4.8.2.1
Rated load 3.4.2.8 4.8.2
Short circuit capability 3.4.2.9 4.8.3.2
Overload 3.4.2.10 4.8.3.3
Efficiency 3.4.2.11 4.8.2.4
Seals 3.4.4.1 4.10.1
Pressure vacuum bleeder 3.4.4.1.5 4.10.2.2
Grounding 3.4.5.8 4.10.9
Surge arrestors 3.4.5.10 4.10.11
Insulation resistance 3.5.1 4.11.1
Dielectric withstanding voltage 3.5.2 4.11.2
Partial discharges 3.5.3 4.11.3
Pulse 3.5.4 4.11.4
Electromagnetic compatiblity 3.5.5 4.11.5

226

~ ~ ~~~~~~~~~
• '~ .. . . . . . ..... "'-..".-"."-'...'..'..""..".'.."'.."..".".'.'.".".'.. ... '"."..". .-
4.6.2 Inspection of preparation for delivery - The inspection of the pre-
servation-packaging and interior package marking shall be in accordance
with the quality conformance inspection requirements of MIL-P-116. The
inspection of the packing and marking for shipment and storage shall be
in accordance with the quality assurance provisions of the applicable
container specification and the marking requirements of MIL-STD-129.

4.7 Methods of examination and test

4.7.1 Visual and mechanical examination

4.7.1.1 External - The converter shall be examined to verify that the


materials, external design and construction, physical dimensions, weight,
marking, and workmanship are in accordance with the applicable requirements
(see 3.2, 3.4.4.4 to 3.4.5.3 inclusive, 3.7, 3.8, and 3.9).

4.7.1.2 Internal - The internal parts of the converter shall be examined to


verify that the materials, internal design and construction, physical
S.:, dimensions, marking, and workmanship are in accordance with the applicable
requirements (see 3.2, 3.4.4.6 to 3.4.5.3 inclusive, 3.4.5.5, 3.4.5.7,
3.7, 3.8, and 3.9). Internal design, construction, and workmanship will
include inspection for:
a. Dirt and debris.
b. Loose ends on wire cooling lacing and ties.
c. Rough surfaces on corona shields.
d. Correct spacing of high voltage wiring.
e. Burns, scratches, foreign deposits, and delamination of
insulating boards.
* f. Grease, oil, or water leaks.

4.7.1.3 Post-test - Converters shall be examined to verify that the pro-


tective coating, filling material, and case construction are in accordance
with the applicable requirements (see 4.3).

p. .

227

- ,. , •. ... • " - "•- - L ,• ° . • -' " •.


.............
'' -'-i' Z• "" " "' : *T. _. . "- . . • .. . ... . , " " "• ° _" •
I.~

4.8 Electrical performance

4.8.1 Test conditions

4.8.1.1 Altitude and temperature - The steady state output characteristics


tests shall be conducted at ambient temperature of 20°C + 10C and ambient
altitude condition -1000 feet to +5000 feet.

4.8.1.2 Input voltage - Nominal input voltage shall be as specified in


the detailed specification.

4.8.1.3 Cooling - The article shall be cooled by passing coolant through


the article heat exchanger.

4.8.1.4 Warm up - Prior to each test, unless otherwise specified, the


equipment shall be temperature stabilized at 230 + 50 C for at least 15
minutes.

4.8.1.5 Instrumentation - All instruments used to measure time, voltage,


% and current shall have an accuracy of 1 percent or less. Instruments shall
have been calibrated within 30 days of the date on which the tests described
in paragraphs 4.8 are conducted unless the instrument history records pro-
vide sufficient evidence to support longer periods between calibration.
All meter indications shall be equal to or within the tolerance range
specified within this specification.

4.8.1.6 Electrical measurements - Steady state electrical measurements


of volts, amperes, ohms, and watts shall be made with laboratory type
instruments having an accuracy of 0.75 percent of full scale.

*4 r-

228
All photographs of oscilloscope traces shall show the sweep time, vertical
deflection sensitivity, rise time of the scope, and amplifier where applicable,
and frequency response at the 3 db point.

All oscillograph recordings shall show a calibration trace, and the cal-
culated values of instantaneous voltage, current, and power from the
recordings shall be accurate to +5 percent. The frequency response of all
recording instruments and cscillographs used in the tests shall be included
in the test data.

Measurements of frequency shall have an accuracy of +1 Hz.

4.8.1.7 Temperature measurements - The accuracy of the temperature measure-


ments shall be +2°C.

4.8.2 Steady state output characteristics - The ability of the unit to


deliver rated load for 5-minutes operation at maximum input voltage for
dc power input, or maximum input voltage and minimum input frequency for
ac power input, shall be demonstrated. After these runs, the unit shall
be loaded at zero, 25%, 50%,and 100% load with nominal input voltage (band
frequency). The unit shall be capable of operating for 5 minutes at each
load level without exceeding the temperature limits (see 1.2.3). The
unit shall be cooled to normal ambient conditions before the start of each
test. Measurements shall be taken and recorded of the output voltage, output
current, input voltage, input current, input power factor (ac input), coolant
temperature,and critical component temperatures which indicate the tempera-
ture rise of t.,e converter.

4.8.2.1 Ripple and modulation - During the full load test (100% rated load),
the perrort modulation Vm shall be measured and recorded; it shall riot
exceed .- where:

229
.1 • • ,,-,•,,':' -. ,, . . :: .,,..-.- ? - . - : . . .. .. . , .-.- .......
V max - min
max +V minn 10
V= ti
V + 11

VWax maximum voltagV


Vmin minimum voltage
4min

4.8.2.2 Operating period - The unit shall be capable of two full load
operating periods (5 minutes each) with 10 minutes maximum cooling period
between operating periods. This shall be demonstrated at thp. conclusion
of the steady state output tests.
4.8.2.3 Input power factor - i•,ring the full load test the input power

factor shall be measured for a converter with an ac power input.

4.8.2.4 Efficiency - Data for determining the efficiency shall be obtained


during the full load and half load tests of 4.8.2.

4.8.2.5 Input current balance - The input current in each phase of the
unit shall be measured during the test of 4.8.2 for a converter with an
ac power input. The current balance shall be taken at full load, 50%
load, and no load.

4.8.3 Transient characteristics

4.8.3.1 Input voltage transient - The input voltage transient define6 in


3.4.2.4, FRgures El and E2, shall be applied to the article power input and
control input with the output loaded to rated load. During this test, the
output voltage sIL- I be within th6 voltage limits of Figure E3.

4.8.3.2 Short circuit test - A short circuit of 750 percent rated current
sustained for 3 seconds shall be applied to the unit to determine conform-
ance to figure E6. There shall be no damage to the converter. The short

230
iid
.us

*~ w1

44

23
circuit shall be applied ane time. The unit shall be carryinq rated current
for at least one minute before application of the short circuit.

4.8.3.3 Overload - The unit shall demonstrate its ability to deliver 150-
"percent rated current for 2 minutes 200-percent rated current for I minute
at an output voltage between 80% and 100% rated voltage with minimum input
voltage and frequency. Each overload shall be applied three times. The
unit shall be temperature stabilized and carrying rated current for at
•-least 1 minute prior to each application of the over-load.

4.8.3.4 Overload at maximum ambient - The test of 4.8.2.3 shall be repeated


at maximum ambient temperature conditions.

4.8.4 Signal processor - The signal processor shall demonstrate its ability
to withstand short circuits, partial discharges lightning and electro-
magnetic pulses by being subjected to 5 high voltage impulses as defined in
paragraph 4.10.9.2. Impulse waveshape and duration are specified in para-
graph 4.11.4. Impulses shall be spaced A0 seconds apart.

4.8.5 Reflected transients - The input current to the converter shall be


monitored during operation with load to demonstrate that the ripple currents
are within the requirements of 3.4.2.13.

-'. 4.8.6 Isolation - The input power leads shall be tested for isolation from
the output pov'er leads to demonstrate compliance with 3.4.2.14.

4.8.7 Remote sensing - The article shall be tested for regulation under
I;-
1.:. local sense and remote sense (with specified line
strate compliance with 3.4.2.15.
voltage drop) to demon-

232

"•,-------------------------------------------------------------.
• '4.9 Environmental tests

4.9.1 Thermal shock (see 3.4.3.1) - The test article shall be tested in
accordance with method 107 of MIL-STD..202. The temperature for step ,3 shall
be the maximum operating temperature for the class. The following details
and exceptions shall apply:
a. Test condition - A, 10 cycles, for qualification
b. After cycling - The test article shall be examined for evidence of
leakage and other visible damage.

4.9.2 Altitude - Altitude tests are not required for hermetically sealed
pressurized subassemblies. Parts such as cables and connectors on sealed
or pressurized units* and unpressurized, unsealed units which are designed
for operation above 10,000 feet altitude shall be tested in accordance with
method 105 of MIL-STD-202. The test articles shall operate at normal volt-
age at the altitude specified in the detailed specification.

4.9.3 Humidity - The unit shall be subjected to the humidity test, Method
103B, of Specification MIL-STD-202. Immediately following this test the
unit shall pass the full load test of 4.8.2 at nominal input conditions
and ambient temperature.

4.9.4 Sand and dust - This test is not applicable for hermetically sealed
or pressurized subassemblies. Unpressurized or unsealed units shall be
tested in accordance with method llOA, of MIL-STD-202. The test articles
shall be non-operating during the test.

4.9.5 Salt spray (corrosion). When specified (see 3.2) - The test article
shall be tested in accordance with method 101 of MIL-STD-202.
a. Test condition - B.
b. Salt solution concentration- 5 percent.

233
c. Examination after exposure - The test article shall be thoroughly
washed. The temperature shall not exceed 380C. The test article
shall be placed in an oven maintained at 50 0 + 30 C for a period of
"24 + 4 hours. At the end of this period, the test article shall be
removed from the oven and examined for corrosion.

4.9.6 Fungus - Unless certification is provided, the test article shall


be tested in accordance with method 508 of MIL-STD-810 (see 3.2).

4.9.7 Shock - The test article shall be tested in accordance with 4.9.7.1,
or when specified (see 3.2), in accordance with 4.9.7.2.

4.9.7.1 Specified pulse - The test article shall be tested in accordance


with method 213 of MIL-STD-202. The following details and exceptions shall
apply:
a. Test condition - I, unless otherwise specified.
b. Examinations after shock - The test article siall be examined for evidence
of leakage and physical damage.

4.9.7.2 High-impact - The test article shall be tested in accordance with


method 207 of MIL-STD-202. The following detail and exception shall apply:

a. Mounting fixtures - Figure "Standard mounting fixtures for electrical


controller parts" of method 207.
b. Examinations after shock - As specified in 4.9.7.1(b)

4.9.8 Vibration - The test article shall be tested in accordance with

4.9.8.1 or 4.9.8.2, as applicable.

4.9.8.1 Vibration, low frequency - The test article shall be tested in


accordance with method 201 of MIL-STD-202. The following details and excep-
tions shall apply:

234
*"a" "..-. ..... .. . . .. ,..*
So , •. ... . , . ...• ... • .. .. .• * *•*.., • '- " -. . . ....* .- -.. .- , •..-. •. - ••
: a. Test and measurements prior to vibrating - Not applicable.
b. Method of mounting - The test article shall be rigidly mounted
by its normal mounting means.
c. Procedure - When specified (see 3.2) the test article shall be placed
in a test chamber and preheated to the specified maximum ambient
temperature for the class (see 3.2) plus one-half the allowable
temperature rise. Vibration in each plane shall begin 5 minutes
after removal from the test chamber.
d. Apparatus - The sequence of vibration shall be as follows: First
vertically, and then horizontally in two mutually perpendicular
directions. Two machines may be used (one vibrating horizontally
and one vibrating vertically), or a single machine may be used which
provides for both vertical and horizontal table motion, or a vertical
vibrating machine, at the option of the supplier.
e. Examinations after vibration - The test article shall be examined
for evidence of leakage and physical damage.

4.9.8.2 Vibration, high frequency (when specified) - The test article


shall be tested in accordance with method 204 of MIL-STD-202. The follow-
ing details and exception shall apply:
a. Mounting of specimens - As specified in 4.9.8.1(b).
b. Test-condition - D, unless otherwise specified.
c. Examinations after vibration - As specified in 4.9.8.1(e).

4.9.9 Flammability (grade 5) - The test article shall be tested in accord-


ance with method Ill of MIL-STD-202. The following details and exception
shall apply:
a. Point of impingement of applied flame - One of the lower free corners,
so that the flame is just in contact with the test article, The free
corners of the test article are those corners which are the greatest
distance from the mounting brackets. However, the flame shall be applied
so that it will impinge upon the corner or area containing the
encapsulating compound.

235
. . , o • -• w .•• • . A••
• .1 S ,s *' .. A
• •-L- 1 .414 14.. -, .= •.- '. • . "- .,- .s s . . • - •. . .- -L•••• .

b. Allowable time for burning of visible flame on specimen - 3 minutes


maximum.
c. Examinations during and after test - The test article shall be examined
for evidence of violent burning which results in an explosive-type fire,
dripping of flaming material, and visible burning which continues
beyond the allowable duration after removal of the applied flame.

4.9.10 Nuclear radiation - When specified by the detail specification, a


nuclear radiation exposure test shall be conducted in accordance with
Standard MIL-STD-446. When required, the unit shall pass the full load
test of 4.8.2 after completion of the radiation exposure.

4.10 Mechanical and electrical tests

4.10.1 Seal - The test article shall be tested in accordance with 4.10.1.1,
4.10.1.2, or 4.10.1.3, as applicable. Any unit or subassembly which shows
evidence of leakage may be given remedial treatment. After completion of
the treatment, the seal test shall be repeated as evidence that such
remedial treatment is adequate. All other units in the lot which have been
given similar satisfactory remedial treatment shall be acceptable.

S4.10.1.1 Liquid-filled units - The test article shall be heated in an oven


maintained at a temperature equal to or not more than 5°C greater than the
sum of the specified maxinum ambient temperature and the allowable tempera-
ture rise (see 3.2), for not less than 6 hours.

4.10.1.2 Gas-filled units - The test article shall be tes+ed in accordance


with method 112 of MIL-STD-202. The following details shall apply:
a. Test condition - C.
b. Leakege-rate sensitivity - 106 atm cm /s.
c. Procedure IV, as specified (see 3.1 and 6.1.2), test for gross
leaks as specified in 4.10.3.

236
i- v; * . 7.r r -& . w'_- r .

••:.' 4.10.2 Auxiliary components - Auxiliary components include pressure and


temperature transducers, fans, pumps, and controls.

4.10.2.1 Transducers - Pressure-vacuum transducer and liquid temperature


transducers shall be tested at least three times during qualification. No
damage to the test assembly or sensor shall result from these tests.

4.10.2.2 Pressure vacuum bleeder - The pressure vacuum bleeder valve shall
be tested at least three times during qualification. No damage to the test
assembly or sensors shall result from these tests.

4.10.2.3 Motors - Fan, pump and control motors shall be tested for electrical
continuity. Fan and pump motors shall function, without failure, during
the life test.

4.10.3 Tank design proof pressure - Proof pressure cycle tests shall be con-
ducted in accordatice with MIL-STD-1540. The temperature of the test shall
be stabilized and maintained at a temperature of 71°C throu, '.

As an alternative the test may be conducted at room temperatL 5st


pressure is suitably adjusted to account for temperature effect. ',.ength
and fracture toughness.

Proof pressure cycles shall consist of raising the tank internal pressure
to 1.5 times the maximum operating pressure specified in the detailed speci-
fication, maintaining this pressure for 5 minutes and then decreasing the
pressure to 0 psig. There shall be no evidence of leakage during the test.

The following test cycle shall be performed:


Test Cycle
Acceptance 1
Qualification 3

237
,.7

•5`7

* At the conclusion of the test there shall be no evidence of yielding of


the tank matf.rial. The volumetric change shall be determined and recorded.
Permanent vo';umetric change shall not exceed 0.2%.

4.10.3.1 Tank design, burst - Design burst pressure test shall be conducted
in accordance with MIL-STD-1540. The temperature of the test shall be
stabilized and maintained at a temperature of 71 0 C throughout the test.

As an alternative, the test may be conducted at room temperature if the pre-


ssure is suitably adjusted to account for temperature effects on strength
* and fracture toughness.

Burst pressure tests shall consist of raising the tank pressure to 4 times
the maximum operating pressure specified in the detailed specification and
Smaintaining this pressure-to verify that the design burst pressure is met
or exceeded. The internal pressure shall be applied at a uniform rate
such that stresses are not imposed due to shock loading.

4.10.3.2 Internal vacuum - The tank shall be evacuated to an 4-e


pressure of 100 pascals, maximum, internal pressure for 15-mi, . ration
while exposed to ambient pressure externally. No permanent deformation
shall be sustained.

4.10.4 Cooling - This test shall be performed during the steady state
conformance operating time tests of paragraph 4,8,2,2, The test shall
be performed with coolant temperatures and equipment temperatures stabtltzed
at ambient temperature of 55 + 5OC. During the test, coolant inlet and
outlet temperatures shall be recorded for test and standby conditions. Coolant
system efficiency shall be determined for each stage of the test, Data on
heat rejection (defined as the difference between input and output power
expressed in kilowatts) shall be furnished for the above tests. The con-
verter shall conform to the specified requirements of paragraph 3.4.3.1(c).

238

;•".,.'..., ' .. ,. -. ,..,. . .. .... .....


.-... .. , .. , .. ,. ,.,... ....-.-........-.
-...-.........-,.......... , .
The coolant system shall be tested in accordance with paragraphs 4.10.3 and
4.1n.3.1. Converter hot spot temperatures shall be measured and recorded.
There shall he no evidence of leakage during the test.

4.10.5 Terminal strength - The article subassemblies shall be tested


as specified il 4.10.5.1 through 4.10.5.2., inclusive, as applicable.
After each test, the terminals shall be examined for loosening and
rupturing and other mechanical damage. Unless otherwise specified, all
terminals on each test sample shall be subjected to the fullowing tests,
up to a maximum of four identical terminals per sample.

4.10.5.1 Pull

4.10.5.1.1 Solid-wire and insulated wire lead terminals - The test article
subassemblies and auxiliary components, such as sensors and motors, shall
be tested in accordance with Method 211 of MIL-STD-202. The following
details shall apply:

a. Test condition - A.
*. •- b. Points of measurement - A force shall be applied in the direction
of the ,..is of termination and shall be increased gradually until
the magnitude specified in table E4 is reached and shall be main-
tained for a perioO of 5 to 10 seconds.

4.10.5.1.2 Solder cerminals - Auxiliary components shall be tested in


accordance with method 211 of MIL-STD-202. The following details shall
apply:
"a. Test condition - A.
b. Points of measurement - A force as specified in table E4 shall be
applied to each terminal at the point where the lead from the
external circuit connects to it. The force shall be applied in

the weakest direction of the terminal and shall be increased


gradually to the specified magnitude and shall be maintained at
.6, that value for a period of 5 to 10 seconds.

239
4 ••• • • -••.,, ,. • ., .• . . , . - . , - . . . .
TABLE E4. Pull.

Cross-sectional area of electrode at its


smallest point at which lead from Force
external circuit connects

Circular mils Pounds

S 2,000 . . 2.0
..-------------------------------
> 2,000 ----------------------- ------ 5.0

4.10.5.2 Twist or bend

4.10.5.2.1 Solid-wire lead terminals (other than printed circuit terminals)


Following the test specified in, 4.10.5.1.1, the article subassembly terminals
shall be tested in accordance with Method 211 of MIL-STD-202. The Following
detail and exception shall apply:
a. Test condition - D.
b. Application of torsion - The body of the component part or the cramped
terminal shall be rotated through 360 degrees about the original axis
of the bent terminal, in alternating directions, for a total of five
rotations, at the rate of approximately 3 seconds per rotation.

4.10.5.2.4% lat solder terminals - Any terminal that shows permanent deforma-
tion greater than 15 degrees of the metal portion of the terminal in the
terminal-pull test specified in 4.10.5.1.2 shall be tested in accordance with
Method 211 of MIL-STD-202. This test does not apply to terminals which show
permanent deformation but are not designed to be bent 45 degrees. The
following detail and exception shall apply:
a. Test condition - B.
b. Number of bending operations - Five times through an angle of 90 dec-ees
(45 degrees each side of center),

-'-.9 • "• •• • ' "- X' ' • ,", - £ • • . ' " 240
' " " ' "' ' "- ' ' ' "-' ••"-"-"- ' "."-"-
4.10.6 Bushings - The insulation level of bushings shall be twice rated
voltage. Bushings shall be given dielectri. withstanuing voltages tests and
impulse tests.

4.10.7 Solderability - Solder connections for converters shall be tested in


accordance with 4.10.7.1 or 4.10.7.2,as applicable. The method in 4.10.7.1
is preferred and shall be specified whenever practicable, otherdise the method
in 4.10.7.2 shall be used.

4.10.7.1 Solder bath method - Solder connections shall be tested in


accordance with Method 208 of MIL-STD-202. The following details shall
apply:
a. Special preparation of specimen - Sample components shall not have been
soldered during any of the previous tests.
b. Number of terminations of each part to be tested - A minimum of two of
each type of terminal.

4.10.7.2 Soldering iron method - The test shall be performed on solder


terminations, attached to converter parts. The solder shall conform to type S,
composition Sn60, of QQ-S-571. The flux shall conform to type A or Was
applicable,of MIL-F-14256. The temperature of the bit shall ie 3000 - 350(C.
The iron and solder shall be applied to the termination for 10 seconds. The
solder shall be applied for the first 2 seconds. Tinning, as evidenced by
the free flowing of the solder with proper wetting of th- '..ernination, shall
be completed within the first two seconds. The part under test shall remain
under standard atmospheric conditions for recovery for fifteen minutes,
before final measurements are made.
a. Special preparation of specimen - The surface shall be smooth and
properly tinned and the solder terminations shall not have been soldered
during aiy previous test.
b. Number of terminations - in accordance with 4.10.7.1

241

• .:...
:. .-.. .-.-..
.. .. .. ....
.• -. ...`.•.. •: .... ...... `...i. .••..•.• ... • .. i.. •. ... `:.•.... .. • .•..-......
..-
•... .. •. ..
c. Examinations of terminations - in accordance with Method 208 of
MIL-STD-202.
d. Soldering irons - The soldering iron shall have one of the following
bit sizes:
(1). 0.3 inch diameter, 1.25 inch exposed length reduced to a
"wedge shape, over a length of approximately 0.4 inch.
"(2). 0.125 inch diameter, 0.5 inch exposed length, reduced to a
wedge shape, over a length of approximately 0.2 inch.
"e. Point of application of soldering iron -1/4 inch from the nearest
insulating material or to one-half the exposed length of the terminal,
whichever point is closer to the insulating material.

4.10.8 Resistance to soldering heat - Converter parts shall be tested in


accordance with 4.10.8.1 or 4.10.8.2, as applicable. The method in 4.10.8.1
is preferred and specified whenever practical, otherwise the method in
4.10.8.1 shall be used. These tests shall apply to conductors and magnetic
devices only,

4.10.8.1 Solder bath method - Converter parts shall be tested in accordance


with Method 210 of MIL-STD-202. The following details shall apply:
a. Special preparation of specimen - Sample units shall not have been
soldered during any of the previous tests.
b. Depth of immersion in the molten solder - To a point 1/4 inch from the
nearest insulating material or to one-half the exposed length of the
terminal, whichever point is closer to the insulating material.
01 +1'/
"c. Test condition - A (350 +10C; immersion, 3 h0/seconds).
d. Examination after test - The parts shall be visually examined and
there shall be no seepage of the impregnant, loosening of the ter'mi-
nal s, or other mechanical damage. The parts shall be checked for
continuity.

242

I -.. , + . = +!+ • . -
C....

"4.10.8.2 Soldering iron method - The test shall be performed on all solder
:• •:• terminu;tions, attached to tlie converter parts. The solder shall conform to

%type -, composition of S0 of QQ-S-571. The flux shall conform to type A or


W,
149 plicab!, of MIL-r-14256. -he temperature of the bit shall be 300 -
•;:.. 2.f.C. 'he iron and solder shall be applied to the termir,ation for 10 seconds.
"The solder shall be applied for the lirst 2 seconds. Tinning, as evidenced
by the free flowing of the solder with proper wetting of the termination,
shall be completed within the first two seconds. The parts under test shall
remain under standard atmospheric conditions for recovery for fifteen minutes,
before final measurements are made.
a. Special preparation of specimen - The surface shall be smooth and
properly tinned and the solder terminations shall not have been
soldered during any previous test.
b. Examinations after test - in accordance with 4.10.8.1.
:C. Soldering irons - The soldering iron shall have one of the following
bit sizes:
1. 0.3 inch diameter, 1.25 inch exposed length reduced to a wedge
shape, over a length of approximately 0.4 inch.
2. 0.125 inch diameter, 0.5 inch exposed length reduced to a wedge
shape, over a lerith of approximately 0.2 inch.
d. Point of application o-! soldering iron - 1/4 inch from the nearest
insulating material or to one-half the exposed length of the terminal
whichever point is closer to the insulating material.

0%} 4.10.9 Grounding and bonding - Resistance measurements shall be conducted on


at least two subassembly ground , representative of the converter. Visual

inspection shall be conducted in all converter subassembly and assembly


grounds and bonds to the airplane structure. Bonds and grounds between'
the converter assembly and subassembly parts shall be in accordance with
MIL-B-5087.

4.' 243

C.-4

S. ; . . *.,. *.
. *.*...
; .. . . . -*.... *.. . , ... . ..*.
.... ... .... . .. . .
4.10.9.1 Grounding - The bonds selected shall be tested with a direct current
source. The measured impedance with average transient current passing
through the joint shall be less than 2.5 milliohms, maximum, between the
converter assembly or subassembly and the airplane structure.

4.10.9.2 Lightning and electromagnetic pulse susceptibility test - A transient


generator similar to that shown in Figure E7shall be used. The voltage
source, capacitor C, and resistor R shall be adjusted to obtain transient "X" in
Figure E-7 for ground potential transient susceptibility test, and "Y" for
interwire intaced transient susceptibility test.
a. Ground potential transient susceptibility test - With the transient
generator output connected between ground and all the ground leads of
"the converter assembly bunched together, and the system operating
under full load conditions, ten positive and ten negative ground
"potential transients (Figure E7, transient X) shall be applied
successively. There shall be no failure of components or impairment
of subsequent performance as a result of the test.

4.10.10 Capacitors - Capacitors shall be tested to determine conformance with

3.4.5.9.

4.10.11 Surge arresters - Surge arrestors shall be disconnected during impulse


testing and dielectric withstanding voltage tests. Surge arresters shall 6e
tested by applying pulses in accordance with IEEE STD 28-1974/ANSI C62.1-1975.

244

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4.11 H.V. Evaluation tests

4.11.1 Insulation resistance - The converter assembly and subassemblies shall


be tested in accordance with Method 302 of MIL-STD-202 The following details
and exceptions shall apply:
a. Test condition - B for qualification inspection; and dc test potentials
from 500 volts to 10,000 volts for quality conformancE inspection,
However, for quality conformance inspection, rejection shall be based on
measurements made at 500 volts.
b. The measurements shall be made at any temperature above 20°C and at ambient
room humidity, but rejections shall be based on measurements made at
25° - 50 C and at a relative humidity not greater than 80 percent.

4.11.2 Dielectric withstanding voltage - Converters shall be tested in accordance


with 4.11.2.1 and 4.11.2.2,when applicable.

4.11.2.1 At atmospheric pressure - Converters shall be tested in accordance with


method 301 of MIL-STD-202. The following details and exceptions shall apply:
a. Magnitude of test voltage shall be 160% workirfi volt-ac.
b. Nature of potential - AC or DC, as applicable.
c. Duration of application of specified test voltage - Minimum of 60 +5
seconds for quality conformance inspection, 1 minute for qualification
inspection.
d. Points of application of test voltage:
1. Input leads - Between input leads and case or ground. Sensurs and
control circuits connected between the input and ground shall be
disconnected.
2. Output and ground - Sensors and control circuits connected to the
high voltage output shall be disconnected.
3. Circuits with direct current rated capacitors shall be-tested with
dc of thie proper polarity.
e. High voltage source shall have a minimum of 5 ktlovolt,.amperes cApcttty,
f. Examination during and after test - The assembly and subassembltes shall be
examined for evidence of arcing, flashover, breakdown of insulatton, and
\ damage.

246

•.,.,.......,-. ....... • -.". .. -..-*.- " .- . % * '..'-'-


.... ... - . *--" .° "'- -'%"
.,* -. .""
4.11.2.2 Altitude. Converter assemblies and subassemblies designed
for operation above 10,000 feeI shall be tested as specified in 4.11.2.1
* and in accordance with Method 105 of MIL-STD-202. The following detail and
exceptions shall apply:

a. Test condition or altitude in feet if below 30,000 feet - As specified


(see 3.1).
b. Magnitude of test voltage shall be 160% working voltage, AC or
DC, as applicable, with polarity in accordance with tested parts.
c. Examination during and after test - Converter assemblies and sub-
assemblies shall be examined for evidence of arcing, flashover,
breakdown of insulation, and damage.

4.11.2.3 At reduced voltage. Converter assemblies and subassemblies


shall be subjected to the dielectric-withstanding voltage tests specified
in 4.11.2.1, except that the test voltages shall be 125% percent of the working
voltage and shall be applied for a period of 60 seconds.

4.11.3 Partial discharges. When speci-fied (see 3.2), convertert shall


be tested in accordance with 4.11.3.1 or 4.11.3.2, or 4.11.3.3, as applicable.
The detector used for this test shall have the sensitivity of one picocoulomb
or less and shall have a reasonably uniform response up to 500 kilohertz.
Partial discharge shall not exceed the following limits for a 3-minute peried.

Voltage Limit Counts/Minute Not to Exceed


KV PC/KV Over Limit P.,-v

DC 1.5 1 5
AC 3 10 10

4.11.3.1 Input circuit. Whe i specified (see 3.2), tht, converte: high voltage input
circuit shall be tested for partial discharges. Partial discharge peak magnitudes shall be
less than the values shown in paragraph 4.11.3,

4.11.3.2 Output circuit. When specified, (see 3.2), the high voltage output circuit
shall be tested for partial discharges. Partial discharge peak magnitudes shall be less than
the values shown in paragraph 4.11.3.

247

"' :""" ' " ' .


". """.. .'.~.*. "' " " ..-.-.. '"'"" ' ::*. :.....;;:
;.-.... ,.:......,.........
, .,.............,....:.....-..-..... ................... <.....,.. ... ;
*. . •:', '- '.- -. ', '.-. - -' .'• •. " . ' -.- ".', ."i'- ". _ -. •, , - ." " .•.
4.11.3.3 Operational. When specified (see 3.2), the partial discharge detector shall
be connected to the converter high voltage output circuit and the unit shall be tested for
partial discharge. Partial discharge peak magnitudes shall be less than the values stated
in paragraph 4.11.3 with the unit supplying rated voltage. The partial discharge test shall
be started 30 seconds after rated voltage is stabilized. The output power shall be near
zero.

4.11.4 Pulse. When pulse tests on line terminals are specified (see 3.2), There shall
be no momentary or intermittent arcing or other indication of breakdown or flashover, nor
shall there be any visible evidence of damage.

4.11.4.1 Connections for pulse tests. In general, the tests shall be applied to each
high voltage input and output terminal, one at a time.

4.11.4.2 Terminals not being tested. Neutral terminals shall be solidly grou.ndcd
except in the case of low impedance windings. Unused high voltage terminals shall be

either solidly grounded or else grounded through a resistor with an ohmic value not in
excess of the following values:

Nominal System
Voltage Resistance
(kV) (Ohms)

345 & below 500


500 400
700 300

4.11.4.3 Wave to be used for pulse tests. A nominal 1.2 x 50 microsecond wave
shall be used for pulse tests.

Positive or negative waves may be used. The polarity shall be in accordance with the
circuit polarity.

The time to crest shall not exceed 2.5 microseconds.

4,11.4.4 Voltage. The basic insulation voltage level to which the convertor shall be
tested is 125 percent rated voltage, or as defined in the detailed specification.

248

"l• . ° =• , .. • - . . . • • . .z
4.11.5 Electromagnetic interference. At no load or minimum load point, as
applicable, half rated load, and rated load, radiated interference, and both the input and
. •output conducted interference shall be measured using the test procedures and applicable
instruments specified in Specification MIL-STD-462 per the requirements set fortih in the
detailed specification and MIL-STD-461.

4.12 Life. The converter shall be subjected to 120 full load cycles, each cycle of
"5minutes duration. The unit shall be allowed to cool a maximum of 25 minutes between
cycles. Room ambient temperature and pressure shall be maintained within the test
facility during the test period. The electrical test circuit shall be devised so that an open
circuit or short circuit during the 120 life cycles shall be detected and the time of failure
recorded. This test may be performed at any ambient temperature provided that the
-5o
maximum operating temperature for the class is held with +]0OCad drtsovayn
no drafts or varying
air velocities are present. During the last cycle of the life test, output voltage shall be
tested to demonstrate compliance with the regulation requirement of 3.4.2.5 and the
ripple/modulation requirement of 3.4.2.7.

4.12.1 Post test. Following the last cycle the no-load output voltage shall be tested
"todemonstrate compliance with the regulation and ripple/modulation requirements.

4.12.2 High voltaxe evaluation. Upon completion of cycling after a minimum of 10


hours accumulated operating time, the converter shall be tested for insulation resistance
(see 4.11.1), and dielectric withstanding voltage (at atmospheric pressure) (see 4.11.2)
using 75 percent of test voltage per 4.11.2.1. Samples shall also be examined for evidence
of physical and electrical damage.

.--

41.

249
5. PREPARATION FOR DELIVERY

5.1 Preservation-packaging - Preservation-packaging shall be level A or C, as


specified.

5.1.1 Level A

5.1.1.1 Cleaning - The converter assemblies and subassemblies shall be cleaned


in accordance with MIL-P-116, process C-l.

5.1.1.2 Drying - Transformc;'s and inductors shall be dried in accordance with


MIL-P-116.

5.1.1.3 Preservawive application - Preservatives shall not be used.

5.1.1.4 Unit packaging - Converter assemblies and subassemblies shall he


individually packaged in accordance with the unit packaging requirements of
table E5 herein and MIL-P-'116,insuring compliance with the general paragraph
under methods of preservation (unit protection) and the physical protection
requirements paragraph therein.

5.1.1.5 Intermediate packaging - Not required.

5.1.2 Level C - Transformers and inductors shall be clean, dry, and individually
packaged in a manner that will afford adequate protection against corrosion,
deterioration, and physical damage during shipment from the supply source to the
first receiving activity.

5.2 Packing - Packing shall be level A, B,or C, as specified.

5.2.1 Level A - The packaged assemblies and subassemblies shall be packed in


accordance with the level A packing requirements of table E5. Boxes conforming
to PPP-B-636 shall have all seams, corners,and manufacturer's joint sealed with

250
tape, two inches minimum width, conforming to PPP-T-60, class 1,or PPP-T-76.
The closure, water-proofing, and banding requirements for the other level A
shipping containers shown in table E5 sh-all be in accordance with the appli-
cable box specification. Banding (reinforcement requirements) for all fiber-
board containers (PPP-B-636 and PPP-B-640) shall be applied i;i accGrdance with
the applicable appendix using non-wetsllic or tape banding only.

5.2.2 Level B - The packaged assemblies and subasseblies shall be packed as


specified in 5.2.1,except that the containers shall conform to the level B
packing requirements of table XI. Box closure shall be in accordance with the
applicable box specification.

5.2.3 Level C - The packaged assemblies and subassemblies shall be packed in

- .,
shipping containers in a manner that will afford adequate protection against
, damage during direct shipment from the supply source to the first receiving
activity. These packs shall conform to the applicable carrier rules and
regulations.

5.2.4 Unitized loads - Unitized loads, commensurate with the level of packing
specified in the contract or order, shall be used whenever total quantities
for shipment to one destination equal 40 cubic feet or more. Quantities less
than 40 cubic feet need not be unitized. Unitized loads shall be uniform in
size and quantities to the Ireatest extent practicable.

5.2.4.1 Level A - Assemblies and subassemblies, packed as specified in 5.2.1,


shall be unitized on pallets in conformance with MIL-STD-147, load type I, with
a fiberboard cap (storage aid 4) positioned over the load.

5.2.4.2 Level B - Assemblies and subassemblies, packed as specified in 5.2.2,


shall be unitized as specified in 5.2.4.1 except that the fiberboards caps
shall be class domestic.

5.2.4.3 Level C - Assemblies and subassemblies, packed as specified in 5.2.3,


shall be unitized with pallets and caps of the type, size, and kind commonly
used for the purpose and shall conform to the applicable carrier rules and
regulations.

251

`* .-`t•? 4.'' % • '% '•-'-- P •-**P ' * "- ,'* .- - .. ...* - .. .. .,. - ." " . . ,
Fit 2.0
_ _ _ _ _
1.0 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

(~. 1 =
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mI a I

'7 At ca

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A4- 04

0.5 04

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3 -3 W q- 00

Is to
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c0 0

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0. 0~

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~ Ira ce~

__________ ________ ________________________cob__


I -___as
___________________________!_
76______________

AI _________ _______ ____252_


5.3 Marking - In addition to any special marking required by the contract or
order, each unit package, supplementary and exterior container and un'itized
load shall be marked in accordance with MIL-STD-129.

5.4 General

5.4.1 Exterior containers - Exterior containers (see 5.2.1, 5.2.2 and 5.2.3)
shall be of a minimum tare and cube consistent with the protection required and
shall contain equal quantities of identical stock numbered items to the greatest
extent practicible.

5.4.2 Air Force requirements - For Air Force requirements submethods IC-3 and
IC-2 with supplementary container conforming to PPP-B-636, class weather
resistant, special requirements shall be used in lieu of submethods IA-8 and
IP-14, respectively (see table XI).

253
6. NOTES
A ".

6.1 Intended use - This specification covers converters, which are used ai
devices to convert either alternating current Into high voltage direct current
or direct current (5kv) into high voltage direct current.

6.2 Ordering data - Procurement documents should specify the following:


a. Title, number, and date of applicable detail specification.
b. MS Part number of the desired converter.
c. Requirements for samp''ng tests (see 4.4).
d. Level of packaging and packing required (see 5.1).
e. Reinspection date marking required (see 5.3).

6.3 Qualification - With respect to products requiring qualification, awards


will be made only for products which are at the time set for opening of bids,
qualified for inclusion in the applicable qualified products list, whether or
not such products have actually been so listed by that dete. The attention of
the suppliers is called to this requirement, and manufacturers are urged to
arrange to have the products that they propose to offer to the Federal Govern-
ment tested for qualification in order that they may be eligible to be awarded
contracts or orders for the products covered by this specification. The
activity responsible for the qualified products list is Electronics Command;
however, information pertaining to qualification of products may be obtained
from the Defense Electronics Supply Center (DESC-E), Dayton, Ohio 45444
(see 3.2).

6.3.1 Submission of drawings - Upon notification of qualificition approval,


the manufacturer should provide two reproducible copies of outline and detail
assembly drawings. Any changes in the r3producible copies from those submitted
with the qualificatien samples should be indicated in detail.

6.3.2 Failure of samples - In case of failure of the sample or samples sub-


mitted, consideration will be given to the request of the manufacturer for
additional tests only after it has been clearly shown that changes have been
made in the product which the activity responsible for the qualification
considers sufficient to warrant additional tests.

254

- a --. . . . . .. . . -
"6.4 Service test - Service tests may be conducted by the procuring activity
and will not s.ubject the unit to conditions beyond the requirements of this
specification. '.'he tests will be conducted on new units to be provided by
the procuring activity.

6.5 Definition - All ac voltages used in this specification should be rms


values.

uNotice: When Government 'rawings, specifications, or other data are


used for any purpose other than in connection with a definitely related
Government procurement'operation, the United States Government thereby
, incurs no responsibility tor any obligation whatsoever; and the fact
that the Government may have formulated, furnished, or in any way
supplied the said drawings, specifications, or other data is not to
be regarded by implication or otherwise as in any manner licensing
the holder or any other person or corporation, or conveying any rights
or permission to manufacture, use, or sell any patented invention that
in any way be related thereto.

-2~

2.
APPENDIX F

AIRCRAFT HIGH VOLTAGE ELECTRIC POWER CHARACTERISTICS CRITERIA DOCUMENT

.4-5

-..,

i . .. .. -I2..
57
AIRCRAFT HIGH VOLTAGE ELECTRIC POWER CHARACTERISTICS CRITERIA DOCUMENT

This criteria document is approved for use by all Departments and


Agencies of the Department of Defense.

25B
1. GENERAL

1.1 Scope This document defines criteria for aircraft high voltage
electric power characteristics present at utilization equipmen~t power-input
terminals, maintained during operation of the generation, distribution and
utilization equipments, and systems applications aspects of utilization
equipment.

1.2 Purpose. The purpose of this criteria document is to provide voltage and
frequency limits and conditions for aircraft high voltage electric power to
be used as criteria for system performance.

2. REFERENCED DOCUMENTS

2.1 The issues of the following documents in effect on date of invita-


tion for bids, form a part of this document to the extent specified herein.

SPECIFICATIONS

Military

MIL-E-6051 Electromagnetic Compatibility Requirements,


Systems

(Copies of specifications, standards, drawings, and publications required


by suppliers in connection with specific procurement functions should be
obtained from the procuring activity or as directed by the contracting officer.)

STANDARDS

Industry

IEEE STD-lO0-1972 IEEE Standard Dictionary of Electrical and


Electronic Terms

259

L 1 .
2.1.1 Addresses for documents referenced herein, not obtainable from the
Government, are as follows:

IEEE Institute of Electrical and Electronics


Engineers, Inc.
345 East 47th Street
New York, NY 10017

260

T'•~~~~~~~~~~~~~~~~~~~.•;
.".--.. .. .-.- ... ." . -...
.. ,.-.
".. •.".......-.. ....-..
•,,.'.-.-.- -. . .- ... ....
3. DEFINITIONS

Definitions of terms not explicitly treated are as given by IEEE


3.1
Standard Dictionary of Electrical and Electronic Terms.

3.2 AC power characteristics. The designation ac power characteristics


relates to alternating voltage and to frequency in single-phase, two-phase,
systens.
tlhree-phase, and multiple-phase ,;wye-connected neutral or ground return
In the event of any conflict between the general requirement of this specifi-
cation and the detailed specification sheet, the latter shall govern.

3.3 AC voltage. The term ac voltage refers to the gross, root mean
square (rms) line-to-line voltage unless otherwise designated.

3.3.1 Nominal AC voltage. The nominal ac voltage magnitudes are per


Table Fl (See 5.1).

.3 Crest factor. The crest factor of the ac voltage waveform is


defined as the ratio of the peak to rms values.

3.5 The designation dc power characteristics


DC power characteristics.
applies to volt-iges in a direct-current, two-wire or ground return system.

3.5.1 Nominal dc voltage. The nominal dc voltage magnitudes are per


Table F1 (See 5.1).

3.6 AC distortion is the rms value of the ac waveform


Distortion.
exclusive of the fundamental. AC distortion includes the components resulting
from amplitude modulation as well as harmonic and non-harmonic components. In
a dc system, distortion is the rms value of the superimposed alternating
voltage.

3.6.1 Distortion factor. The ac distortion factor is the ratio of the


ac distortion to the rms value of the fundamental component. The dc distortion
factor is the ra'*io of the dc distortion to the average dc voltage.

261

-,
qA• , -• .; ,. . - .,. , , . -. . •-, . -. - • .. -,... . . . . • - , . • , . . . . . . . , ,- . , - - . . . . - - , - - .. -,. - - . .
W". v

3.6.2 Distortion spectrum. The distortion spectrum quantifies ac


distortion and dc distortion in terms of the amplitude of each frequency
component. The distortion spectrum includes the components resulting from
amplitude and frequency modulation as well as harmonic and non-harmonic
components of the ac waveform.

3.7 Electrical power characteristics. The electrical power character-


istics include values and limits .altage
o and frequency parameters, and
include related characteristics pertinent to electromagnetic compatibility
requirements as well as those designated in ac and dc subcategories. These
characteristics are representative of steady and transient states experienced
in system operation during all phases of aircraft operation.

3.8 Electric power system. The aircraft high voltage electric power
system is that group of connected generation, distribution, protective and
conversion equipments active in supplying high voltaqe electric power to
utilization equipments.

3.9 Electromagnetic compatibility. The capability of systems and


associated equipment to perform at specified levels in the total electro-
magnetic environment.

3.10 Frequency. Frequency is equal to the reciprocal of the alternation


period of the fundamental of the ac voltage. The unit of frequency is the
number of alternations per second of the ac voltage and is designated hertz (Hz.).

3.10.1 Nominal frequency. The nominal frequency is per Table Fl.

3.10.2 Frequency drift. Frequency drift is the slow and random variation
of the controlled frequency level within steady state limits due to such
influences as enviromnental effects and aging.

3.10.2.1 Frequency drift rate. The frequency drift rate is the time rate
of frequency change due to frequency drift.

262
TABLE Fl: Nominal Voltage Values

DC VOLTAGE AC VOLTAGE FREQUENCY


RMS PEAK
30 1,000/577 1,414/816 200/400/800/2000 Hz
30 29,550/17,100 41,790/24,180 200/400/800/2000 Hz
20 1,000/707 1,414/1000 200/400/800/2000 Hz
20 29,550/20,890 41,790/29,550 200/400/800/2000 Hz

2-5 kV DC
5-10 kV DC

20 kV rectified

40 kV rectified
"125 kV DC

;4.1

-wj

Z63
3.10.3 Frequency modulation. Frequency modulation is defined as differ-
"ence between maximum and minimum values of I/T, where T is the period of one
cycle of the fundamental of the phase voltage. When applicable, the rate at
which lI/T values repeat cyclically is called the frequency modulation rate.

3.10.4 Frequency transient. The frequency transient is the locus of


values defined by the reciprocals of sequential alternation periods of the ac
voltage, in instances when the frequency departs from the steady-state value.

3.11 Overvoltage and undeyvoltale. Overvoltage and undervoltage are


those voltages which exceed the combined steady state and surge limits and
are usually terminated by the action of protective devices. Although generally
short lived, they differ from surges in the sense that, if left unchecked, they
would continue indefinitely at their fixed magnitude or until some breakdown
in operation was precipitated. Overvoltage and undervoltage can exist
indefinitely at values slightly exceeding steady state limits but within the
trin limits of the power source protection circuits. They are generally due
to loss of regulator control, to unbalance, or to faults, i.e., causes other
than those producing surge voltages. On ac systems they apply on all phases
or only one phase.

3.12 Ripple amplitude. The ripple amplitude is the maximum value of the
difference betw-en the average and the instantaneous values of a pulsating
unidirectional wave. (See 2.1, IEEE Z'•tndard.)

3.13 Steady state. A steady state condition of the characteristics is


one in which the characteristic shows only negligible change throughout an
arbitrarily! long period of time.

3.14 Utilization equipment. The load equipment is that which receives


power from the electric power system. It may be an individual unit, a set of
equipments or a complete subsystem receiving power through conmon equipment
terminals or power converters.

264

.... ' - -•' -.-.,.


-":••""..--""-" -" ::::::::::::::: : ::.::::::" :•;: :•:• : .- :..:
,~
:• . .:*. -: : **::.:: . ii
- 3.14.1 Utilization equipMent terminals. Utilization equipment terminals
" through which the electric power system is connected to the utilization equip-
ment are attached to the equipment or are immediately adjacent to the equipment
itself. Power interconnections within the utilization equipment are excluded.

3.15 Voltage phase difference. The voltage phase difference is the


difference in electrical degrees between the fundamental components of any two
phase voltages taken at consecutive zero or dc level crossings of their
instantaneous values traced in the negative to positive directions.

3.16 Voltage surge. The voltage surge is defined as a transient


departure of the peak values of voltage from the peak instantaneous value of
the steady state voltage, persisting for periods in excess of 0.1 microsecond,
followed by recovery to within peak values corresponding to steady state.
Surges are caused by load changes, and are not expected to activate protective
equipment.

3.17 Voltage spike. The spike is a transient of total duration normally


* less than 0.1 microsecond and is superimposed on the otherwise unaltered
instantaneous voltage. Spikes may be characterized here in the time domain
in terms of voltage with parameters of duration, risetime and energy. They
may also be characterized equivalently in terms of Fourier component amplitudes
as a function of frequency. Spikes are not expected to activate protective
equipment.

3.18 Voltage unbalance. Voltage unbalance is defined as the maximum


difference among phase voltage magnitudes at the utilization equipment terminals.

3.19 Reference ground. The primary aircraft structure is the reference


ground for both the ac and dc electrical power systems in metal structure
aircraft. In composite structure aircraft, reference ground is additionally
designated for specific systems. In some instances, it may be possible to
utilize as ground the negative polarity wiring of the dc system, the neutral of
the three-phase or multi-phase ac system, or one "side" of a single-phase ac
system.

265

t*,, . • - S. . .Z *.. . . . . .- .• . . . . -. . . .. . . .. .. . . .
3.20 Power sensitivity. Power sensitivity of utilization equipment is
the ratio of incremental output changes to incremental input changes for
specified output performance quantities and specified voltage or frequency
-, input-power changes. (See IEEE STD, 2.1)

a,..

•..:

266

,4
'1 *** ~4. GENEfRAL REQUIREMENTS

4.1 System equipment compatibility. The characteristics defined in this


standard shall be maintained at the utilization equipwent terminals during the
operation of all expected combinations of power source, distribution, and
utilization equipment. System operating modes outside the conditions defined
by this standard will be permitted only when specifically authorized.

4.2 Conformance tests. Tests for conformance of the aircraft high


voltage electric system to the characteristics stipulated in this document
shall be defined as part of the procurement specifications to which this
document is applicable, and shall be subject to the approval of the procuring
activity.

267
5. DETAIL REQUIREMENTS

5.1 AC power characteristics. AC power characteristics are those of a


single-phase, two-phase, three-phase, or multi-phase wye-connected neutral
or ground return system having the nominal voltage and the nominal frequency
per Table Fl.

5.1.1 Steady state.

5.1.1.1 AC voltage magnitude. The steady state phase-voltage with load

shall be within +5%of nominal voltage.

5.1.1.2 Voltage unbalance. Voltage unbalance applied to the terminals


of equipment using a three-phase or multi-phase supply shall Le less than 3
percent.

5.1.1.3 Voltage phase difference. The voltage phase Jifference shall be


within 1200 +20 for three-phase power and within 900 +20 for two-phase power.

5.1.1.4 Phase sequence. The phase sequence is A-P-C for three-phase


power or A-B for two-phase power, corresponding to phase wire markings.
See Figure Fl.

268

268
A

FUDAENTAL

COMPONENT OF VOLTAGE MAI


PHASE VOLTAGE DIFFERENCE

;j FUNDAMENTANDOMPNTEN g
VOLTAGE COPOF
VOLAAG OFAS
PHASE VOLTAERDEFERNC

T A
C

-I

THREEPPHASEPPOWER

Figure Fl: Phalo Diahnm ShowirV Roequired Phase Sequence Relatonship (Soe 5.1.1.4)

269
-7°

5.1.1.5 AC vivp,--- .iistortion.


The distortion factor for the phase
*L. voltage waveform t exceed 0.1 nor shall the limits of the ac distortion
.C
*•) spectrum exceed the -ovelope shown in Fig. F2. The crest factor shall not
exceed 1.41 +0.10, nor shall the dc component exceed 0.1 percent.

5.1.1.6 Amplitude npdulation.


The amplitude modulation components
(sidebands) resulting from all modulating influences shall not exceed 1 percent.
(S±:e 6.5)

5.1.1.7 System freiquency. The system frequency shall be per Table Fl.

5.1.1.8 Frequency modulation. Modulated frequency deviation shall not


exceed the limits specified in Fig. F3.

5.1.1.9 Frequency drift. Frequency drift when loaded shall not exceed
the .tteady state limits, nor occur et a rate of change exceeding 1 percent
per minute.

5.1.2 Transient.

5.1.2.1 VoltAge surge. Voltage surges shall not exceed the limits shown
in Figure ?4.

5.1.2.2 Voltage spike, Utilization equipment shall be capable of with-


standing voltage spikes as; defined in 5.4.5.1. (See also 6.2.)

5.1.3 Frequency transient limits (frequency surge). The frequency


transient shall be within +10 percent, returning to within +5 percent of
nominal frequency in one setond. The ratet of frequency change shall not
excetl 1000 Hz., 'econd for any periom greater than 15 millibeconds.

5.1.4 Oervol.tge and undervoltage. The ac overvolti.qe values she I not


Se~xceed the upper limit shown in Figure F5. The ac underyoltaqe snall not "Xceed
the lower limit of Fiqure F5.

?.70

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'a,. *5**q

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ZWtS 3WUIAV NOUd UOUVIAW) AOflMKV iJO3W3d


I..

'C

272
II

'.4.

- M- a

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V#U TMV MVIW 3VM

2731
z
IL 0

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274
5.1.5 Out-of-tolerance frequency (over- and under-frequency). The limits
shall not exceed nominal frequency +5 percent for more than 5 seconds, or for an
interval specifically authorized.

5.2 DC power characteristics. DC power characteristics are those of a


direct-current, two-wire or ground return system having a nominal voltage per
Table Fl.

5.2.1 Steady state (load requirements).

5.2.1,1 DC voltage magnitude. The dc voltrage shall be within +5%of


nominal value.

5.2.1.2 DC distortion. The dc distortion factor shall not exceed 0.02 nor
shall the dc distortion spectrum exceed the limits shown in Fig. F6. The ripple
amplitude shall not exceed 1 percent (peak).

5.2.2 Transient.

5.2.2.1 Voltage transient. The maximum value of the dc voltage transient


shall not exceed the limits shown in Fig. F7.

5.2.2.2 Voltage spike. The requirements of 5.1.2.2 also apply to this


parrgraph.

5.2.3 Overvoltage and undervoltage. The dc overvoltage values shall not


exceed the upper limit shown in Figure F8. The dc undervoltage shall not exceed
the upper limit shown in Figure F8.

5.3 Ground su~ort power characteristics. Power supplied by ground support


generation systems shall result in power at the utilization equipment terminalc
at least within the limits specified in 5.1 and 5.2. (See 4.1.)

- 2...

•,',=275

- . o a . . a a a * a aoa a a. . . . . . . . .a.o
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o.

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0~~ I 0
TDVUO NV 4 *0U1M (4)M%

.427.
120%

MAXIMUM LIMIT

-IOW

.2U.

0 6 10 is 20 25 30 36

• •TIlME FROM ONE OF TRANSIENT. SFCOWDS

*" . ,5. " ;-, .,'• ' .- ' - .. " • .- '•- , . " '""- .' . ; •" " "•" ' - - -.- . ' .. ' .- • . . - ". - . ' - -
S~~Fipum F7T: Envio* of IDc Vo,•w TrwmnMtn (sm U.2.21)

)277

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--- .. , . . .. . .. .. . - - - -,..
4j*

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ILIGAIVNION
i33Vz

4., -~ 278
,f.h 5.3.1 AC voltage.

5.3.1.1 AC voltage magnitude. The voltage range at the point of connec-


tion to the aircraft shall be per Table Fl.

* 5.4 System operation of utilization equipmnt.

5.4.1 Power types. Utilization equipment shall operate from one or more
of the types of power defined in Table Fl,as required by the equipment
specifications.

5.4.2 Equipment performance. The utilization equipment shall function


as follows:

a. Unless otherwise specified, all performance requirements must be


met when the utilization equipment is supplied one or more power types specified
in 5.4.1 above, when operated in a system, and when operated within the appro-
priate limits specified in 5.1 and 5.2, which must be within the limits of the
equipment specification.

L. Utilization equipment need not maintain required performance


r':-n supplied voltages between the applicable surge limits and the ;issociated
o-ýrvoltages and undervoltages of 5.1.4 and 5.Z.3, and frequencies between
applicable steady state limits and the transient limits of 5.1.3, unless
otherwise required. (See 3.11)

c. Exposure to the voltages and frequencies stipulated above in


this paragraph 5.4.2 shall not result in an unsafe condition, nor impair the
ability of utilization equipment to maintain performance requirements in
subsequent operation. After such exposure the utilization equipment shall be
automatically restored to specified operating performance unless otherwise
required.

5.4.3 Precisicn power. The electric power system shall not be used
directly as a source of reference voltages or frequencies, or timing signals
"M
. unless specifically authorized by the procuring activity.

279
Partial power failure. The failure of one cr more phases of a
5.4.4
polyphase equipment, or the loss of power to any or all pairs of power-input
terminals of equipments which require both ac and dc power, shall not result
in an unsafe condition.

5.4.5 Power sensitivity tests. Tests for utilization equipment sensi-


tivity to the appropriate power conditions shall be as defined in the system
procurement specification. Detail equipment tL "s will not be invoked unless
specifically called out. (See 6.3.)

5.4.5.1 Voltage spike. Subsequent to the application of a spike wave-


form to the power-input terminals of utilization equipment
functioning according to corresponding detail specification, this Equipment
shall meet 5.4.2. The spike waveform, produced by a power source with an
impedance of 50 +5 ohms, shall satisfy the following requirements:

Maximum Peak Voltage: 160 percent rated peak voltage.


. Risetime: 0.01 +.002 microsecond
Falltime: 0.1 +.002 microsecond
Pulsewidth: (50% amplitude poirts): ±0.01 microsecond.
Repetition rate (aperiodic): Not greater than 50 Hz.
Source energy capability: Not less than 5i0 J.

See F%,j. F9 for waveform example.

6. NOTES.

6.1 Total system characteristics. This document specifies selected


characteristics of high voltage electric power in a high voltage, high power
aircraft system. These characteristics are the result of the mutual influences
of the electric power generation, distribution,and load equipment. Load equip-
ment should be designed to minimize any deleterious reactions and effects it
may have on power quclity. It is not the intent of this document to specify
the manner in which these characteristics are attained. Further detail speci-
fications contain adcltional inits and constraints iu.'ich are the resoonsibility -

of the designer to recognize in the context of total system limits.

280

•' ." ' -, . -' . *- *- . - - -. :- . •* .': • I "• :


410

200 -0

Rt=L*
.01s 0 .u IEI
sU
.4! jI
IIIm

Rom~~i
nbf IAOPWat twtTwPima S

-08
6.2 Spikes. The random and periodic occurrence of voltage spikes
superimposed on other voltage characteristics specified by this standard is
acknowledged. Their impact on equipment may range from temporary degradation
of performance to destruction of equipment. The predominance of their high
frequency behavior, however, makes necessary the recognition of their potential
influence as a form of electromagnetic interference. No spike suppression is
explicitly imposed on specific induction devices or elements such as relays
and solenoids.

Spike measurements on operating systems have led to the following


estimates:

Magnitude: Within the range of +500 percent of nominal voltage


Duration: Not less than 500 nanoseconds.
Risetime: Not less than 20 nanoseconds.
Energy: Not greater than 50 joules.
Ringing Frequency: Not greater than 50 MHz.

These may be considered worst case on the basis of present knowledge. They
are not to be misconstrued with values that may be derived for a spike
susceptibility test for individual utilization equipments.

6.3 Power sensitivity and system confcrmance tests. Power sensitivity


tests for individual utilization equi;ment must be developed further and
adapted to a new standard to serve as a companion to this criteria document.
It is also necessary to develop conformance testing methods and standards
based on this criteria document with allowance for individual aircraft
requirements. (*See 3.20.)

* In the context of this standard, and in the absences of correlation


between individual equipment performance and that in a system, the
inclusion of such tests is intended to indicate qualification and
compatibility for subsequent system application.

282

....... .. .. .. ... . . .
6.4 DC distortion: individual equipment vs. system effects. Tests have
disclo-..ed that individual power source tests into dummy loads demonstrate
higher frequency-component amplitudes than are indicated by Fig. FS. It is
important to recognize this fact in connection with 5.2.1.2, 5.4.5 and 6.3.

6.5 Amplitude modulation. Amplitude modulation effects are predominantly


identified with periodic load changes. The resultant rms level is below that
indicated by the ac distortion (Fig. F2)derived as the covering envelope of
measured spectral values. The off-carrier sideband components, how.ever, are
not required to fall off, in proportion to their frequercy departure from the
carrier.

6.6 International Standardization Agreement. Certain provisions of this


standard are subject to international standardization agreements: NATO STAGA6
3456, NATO STANAG 3516, ASCC Air Standard 12/10, and Air Standard 12/19. When
amendment, revisioi. or cancellation of this standard is prCpossd, that will
affect or violate the international agreement concerned, the preparing activity
will take appropriate reconciliation action through international standardiza-
tion channels, including departmental offi,...s, if required.

283

,I . .* .'.S .i.'.' ".S."- .. -.. '.- ... ..- '..- .... " ........
'.-..... •.. .•. . .. " . - ,
APPENDIX G

HIGH VOLTAGE POWER SOURCES CRITERIA DOCUMENT

285

r; V' •7.
HIGH VOLTAGE POWER SOURCE CRITERIA DOCUMENT

This specification is approved for use by all Departments


and Agencies of the Department of Defense.

lo

"I
.I
1. SCOPE

1.1 Scope - This specification covers the general requirements for


high voltage, high power, short lifetime power sources for use in
airborne equipment.

1.2 Power Sources - The power sources are defined as electromagnetic

nmachincs that generate electric power with all ancillary equipment


necessary to make it a functiornal unit, when integrated with the prime
energy source or supply and output equipment for conversion and usage
of the electric power. Unless otherwise specified, the duty cycle shall
consist of (1) start-up from a static, de-energized state upon demand
to rated output within a specified period with sudden application of the
load, (2) transmission of electric power to the conversion equipment for
five minutes minimum, and (3) sudden removal of 1.0 per unit load.

1.3 Classification - The power sources shall be of the following


types and classes as specified:

.. Type 1 - Magnetohydrodynamic generator


Class A - High. voltage, 5-10KV DC
Class B - Low voltage, 2-5KV DC
Type 2 - Alternating current generators
Class C - High voltage, 40KV DC rectified
Class D - Intermediate voltage, 20KV DC rectified
Clss E - Low voltage, 537/1000 volts AC

The power requirements will be defined in the detailed specification.

;I

287

........ .. -
Io

2. REQUIREMENTS

2.1 The following documents, of the issue in effect on date of invitation


for bids or request for proposal, form a part of this specification to the
extent specified herein.

SPECIFICATION
FEDERAL
BB-H-1168 - Helium, Technical Grade
BB-S-1419 - Sulfur Hexafluoride, Technical Grade
L-P-513 - Plastic Sheet, Laminated, Thermosetting, Paper-Base,
Phenolic Resin
QQ-S-571 - Solder, Tin Alloy; Tin-Lead Alloy; and Lead Alloy
PPP-B-566 - Boxes, Folding, Paperboard
PPP-B-601 - Boxes, Wood, Cleated-Plywood
PPP-B-621 - Boxes, Wood, Nailed and Lock-Corner
PPP-B-636 - Boxes, Shipping, Fiberboard
PPP-B-640 - Boxes, Fiberboard, Corrugated, Triple-Wall
PPP-B-676 - Boxes, Setup
PPP-T-60 - Tape, Packaging, Waterproof
PPP-T-76 - Tape, Pressure-Sensitive Adhesive Paper, (for
Carton Sealing)
'V-I-530 - Insulating Oils

MILITARY
MIL-1-lO - Insulating Materials, Electrical, Ceramic, Class L
MIL-M-14 - Molding Plastics and Molded Plastic Parts, Thermosetting
MIL-W-76 - Wire and Cable, Hookup, Electrical, Insulated
MIL-P-116 - Preservation-Packaging, Methods of
MIL-P-997 - Plastic Material, Laminated, Thermosetting, Electrical
Insulation: Sheets, Glass Cloth, Silicone Resin
MIL-D-IO00 - Drawings, Engineering and Associated Lists
MIL-B-5087 - Bonding, Electrical, and Lightning Protection, for
Aerospace Systems
MIL-E-5400 - Electronic Equipment, Aircraft, General Specification for

288
,,,
".•
•...;•...••:•.,
. • . ,"
.• '... , '..I,.•,
'..- .' .' .. . . .. ". ". .. . ... . ,. .. .' .' .' .. .. .. . . -" . ."•".. . _
,MIL-F-5504 - Filter and Filter Elements, Fluid Pressure,
Hydr.aulic Micronic Type
MIL-F-5591 - Fastener, Panel
MIL-L-7808 - Lubricating Oil, Aircraft Turbine Engine,
Synthetic Base
MIL-M-7969 - Motors, Alternating Current, 400 Hz, 115/200-Volts
System, Aircraft, Class A and Class B, General
Specification for
MIL-F-14256 - Flux, Soldering, Liquid (Rosin Base)
MIL-P-15037 - Plastic Sheet, Laminated, Thermosetting, Class-Cloth
Mel amine-Resin
MIL-P-15047 - Plastic-Material, Laminated Thermosetting, Sheets,
Nylon Fabric Base, Phenolic-Resin
MIL-W-16876 - Wire, Electrical, Insulated, High Temperature
MIL-P-18177 - Plastic Sheet, Laminated, Thermosetting, Glass
Fiber-Base, Epoxy Resin
MIL-C-26074 -
Coating, Electrodeless Nickel, Requirements for
MIL-C-45662 -
Calibration System Requirements
MIL-W-8387 -
Wire, Electric, Polyimide Insulated, Copper
and Copper Alloy
(See detailed specification for lisi of associated specification
sheets or military standards.)

STANDARDS
MILITARY
MIL-STD-129 - Marking for Shipment and Storage
MIL-STD-147 - Palletized Unit Loads on 40" x 48" Pallets
tIIL-STD-202 - Test Methods for Electronic and Electrical Component
Parts
MIL-STD-446 - Environmental Requirements for Electronic Component
Parts

289

,•,• j
,:;;-',.
.'.'-" .V• .. . I ' .. .: '.-.-,. ...-. , . , , . . . . . , . V, ,. . . ...- . .*
•;,K•'•;i~~~~~~~~~~~~~~~
. .,". ~~~~~~..-;.."
. . ' ....., '- .".:.".":
.- .-. - ".'."."...".- .- .-. .- "." -'". * .-. ,' .- .V-. .' ,* ". ". -. -. ..-. "*
MIL-STD-454 - Standard, General Requiremnents for Electronic Equipment
MIL-STD-461 - Electromagnetic Interfer ice Characteristics Require-
ments for Equipment
MIL-STD-462 - Electromagnetic Interference Characteristics,
Measurement of
MIL-STD-470 - Maintainability, Program Requirements
MIL-STD-471 - Maintainability Demonstration
MIL-STD.-781 - Reliability Tests, Exponential Distribution
MIL-STD-785 - Reliability Program for Systems and Equipment
Development and Production
MIL-STD-831 - Test Reports, Preparation of
MIL-STD-882 - System Safety Program for System and Associated
Subsystems and Equipment, Requirements for
MIL-STD-810 - Environmental Tes" Methods
MIL-STD-1285 - Marking of Electrical and Electronic Parts
MIL-STD-1540 - Test Requirements for Space Vehicles
MS 33586 - Metals, Definition of Dissimilar

(Copies of specificatiions, standards, drawings, and publications


required by contractors in connection with specific procurement
functions should be obtained from t,',e procuring activity or as
directed by the contracting officer.)

2.2 Other publications - The following document forms a part of this specifica-
tion to the extent specified herein. Unless otherwise indicated, the issue in
effect on date of invitation for bids or request for proposal shall apply.

NEMA Publication No. 109 - IEEE-EEI-NEMA Standard Basic Insulation


!evel
ASTM-AI20 - Black and Hot-Dipped Zinc Coated
(Galvanized), Welded and Seamless Pipe
for Ordinary Uses
ASTM-A181 -. Rolled or Forged Steel Pipe Flanges,
Forged Fittings, and Valves on Parts
for High-Temperature Service

290
',4
ASTM D1868 Detection and Measurement of Discharge (Corona)
Pulses in Evaluation of Insulation Systems

ASTI D3382-75 Measurement of Energy and Integrated Charge Transfer


Due to Partial Discharges (Corona) Using Bridge
Techniques

ANSI B16.36-1975 Steel Orifice Flanges, Class 300, 600, 900, 1500
ard 2500

ANSI B31.1-1973 Power Piping

ANSI C57.1200-1973 General Requirements fur Distribution, Power and


Regulating Transformers

APPENDIX A High Voltage Cable Criteria Document

APPENDIX C High Voltage Capacitor Criteria Document

APPENDIX F Aircraft High Voltage Electric Power Characteristics


Criteria Document

AFWAL-TR-82-2057, High Voltage Design Guide: Aircraft


Vol. 4
/

NATIONAL BUREAU OF STANDARDS


Handbook H28 Screw-Thread Standards for Federal Services

Handbook MCIC-HB-04 Handbook on Materials for Super Conducting Machinery

Institude of Electrical and Electronic Engineers


IEEE STD-4, IEEE Standard Techniques for High Voltage Testing
IEEE STID-28Surqs Artesters for Alternatint Current Peww Circuits

(Application for copies should be addressed to the Superintendent of Documents,


Government Printing Office, Washington, D.C. 20402.)

"4 291
4. '
3. REQUIREMENTS

3.1 Description - This specification covers the requirements 'or high


power, high voltage, short lifetime electric power sources for use
in or in conjunction with airborne equipment. The power sources shall
be complete with accessories and auxiliary equipment as specified
herein and required for operation as specified herein. The power
sources shall be rated as follows:

"a. Alternating current generator, class C, D or E, power output and


operating time shall be as defined in the detailed specification.

b. Direct current output, magnetohydrodynamic generator, class A or B,


power output and operating time shall be as defined in the detailed
specification.

c. Duty cycle- Aduty cycle of 2.5 minutes per hour is required for
each class generator.

All auxil aries shall be suitable for operation frcm either the 400 Hz
airplane power system or from the output of the selected power source.

3.1.1 Reliability - The power source shall have a reliability of


100 hours accumulative operating time between failures, using accept/reject
criteria of MIL-STD-781, test plan IVa.

3.2 Specification sheets - The individoual equipment requirement shall


be as specified herein and in accordance with the applicable detail speci-
fication sheets. Whenever the requirements of this specification dndthe
detail specification or standard conflict, the requirements of the
detail specification or standard shall govern. Any deviation from

292
S•,
• .. .........• • •.. • . .- :,-:-r-
I• :,-.•'
• ,. , ,, ,,; ,• , • o- -° -- - - -- .-- - - -. .-- .- - -r

t.I

this specification or from subsidiary specifications or standards,


where applicable, must be specifically approved in writing by the
procuring activity.

3.7.1 'irst article - When specified, the supplier shall furnish


a conkp: :-e power source for first article inspection and approval.
unless otherwise specified, the first arti,. e shall consist of one
complete power' source, including auxiliary cooling and control equipment.

3.2.2 Information to be furnished with first article - The applicable


information outlined in 6.2 shall be furnished with the first article,
t;P)ther with any other pertinent information as required by the Goverment.

,terials and 'cmponents - Materials and components not Oefinitely


.,
'efled shall be selected by the contractor and shall be subject to
'
all provisions of this specification.

'. •3.3.1 Selection of materials, parts, and processes ,. Materials, parts,


aimd processes shall conform to applicable Government specifications.
Materials conforming to contractor's specifications may be used provided
the specifications are approved by the Government and contain provisions
for' adequate tests. The use of contractor',i specifications will not
constitute waiver of Government inspection.

3.3.1.1 Substitution of materials - If the supplier desires to


substitute another material for a specified material or fabricated part,
he shall svbmit a statement to the Government describing the proposed
substitution, together with evidence to substantiate his claims that
such substitute is equivalent. At the discretion of the Government,
test samples may be required to prove the suitability of the proposed
substitute. Before such substitutions are made, approval for each
substitution shall be obtained in writing from the Government.

293
3.3.1.2 Flammable material - Insofar as practicable, materials used
in the construction, of the power source shall be nonflammable and
nonexplosive.

3.3.i.3 Thermal and sound insulating material - Unless otherwise


specified (see 6.2.1), the thermal and sound insulating material
shall conform to the following requirements:

a. Noncapillary, nonhygroscopic, and free from perceptible odors.


b. R istant to attack by vermin and mildew.
c. Fire retardant, unaffected by battery electrolyte or petroleum
derivatives.
d. Capable of maintaining its shape, position, and consistency inher-
ently or by suitable ,-etaining methods under conditions of vibra-
tion and temperature specified herein.
e. Resistant to or protected from abrasion, if exposed, and shall
be replaceable, and bondable to metal.

3.3.1.4 Corrosive materials - Corrosive materials used in any of the


manufacturing processes shall be removed or neutralized so that no
corrosion will result from such use. Insofar as practicable, materials
used in the construction of the power source shall be noncorrosive.

3.3.2 Electrical insulating materials - Electrical insulating mnte-


rials used, including plastics, fabrics, and protective finishes,
shall be moisture resistant and shall not support fungus growth. The
nonmetals shall not support combustion and shall not L, adversely
affected by weather, aircraft fluids, temperatures, and ambient
conditions encountered during operation of the aircraft. Nonmetals
may be treateo to conform to this requirement.

3.3.2.1 Laminated phenolic - Laminated phenolic materials shall conform


to MIL-P-997, L-P-513, MIL-P-15037 and MIL-P-15047. When electrical
characteristics are involved, only natural uncolored materials shall be
used.

294
"3.3.2.2 Molded phenolic or melamine - Molded phenolic or melamine
materials shall conform to MIL-M-14.

3.3.2.3 Ceramic (external use) - Ceramic materials shall conform to


MIL-I-IO.

3.3.2.4 Laminated plastic sheet - Laminated plastic sheet, epoxy,


shall conform to MIL-P-18177.

3.3.2.5 Insulating Fluids - Insulating oil and gases shall be free


of particles. Samples shall be evaluated to assure the virgin fluid
is free of particles. Provisions shall be provided to check purity
of fluid and for replacement of fluid.

3.3.2.5.1 Coolants - Coolant fluids circulated through passages or


around conductors shall have adequate spacing to allow unrestricted
circulation. Insulated conductors shall have smooth void-free
construction to prevent cavitation, or stagnation of the fluid at all
temperatures covered by this specification.

Coolants may be passed through hollow strands (conductors) provided


the electrical characteristics of the part is not electrically,
thermally, or mechanically deteriorated.

3.3.2.5.2 Filtering - Filters shall be installed in the coolant


and insulating loops which will remove solid waste products. Provision
shall be made for chemically checking the coolant for impurities.
Refurbishment of fluids shall be made periodically to assure non-
contamination.

3.3.2.6 Insulating gases - Insulating gases may be either pure or a


mixture. Gas or gas purity shall be as specified by BB-H-1168,
BB-S-1419 or equivalent, to assure the virgin material is free of
impurities such as water.

295

,a , .. .. . , ,-.. .. ..
3.3.2.6.1 Gas-filled units - When the unit is gas filled it shall be as
specified in 4.12.1.2, and the leak rate shall not exceed 10- Pascal-cubic
centimeter per second.

3.3.2.6;2 Pressure-vacuum transducer - A pressure-vacuum transducer shall be


furnished for each pressurized sealed-tank and/or gas-oil-seal construction.

3.3.2.6.3 Liquid temperature transducer - A liquid temperature transducer


S*shall be furnished for units of the sealed tank liquid filled construction.

3.3.2.6.4 Pressure-vacuum bleeder - A pressure-vacuum bleeder device shall


be set to operate at the maximum operating pressure (positive and negative)
indicated on the nameplate. Effluent gases/liquids shall be ported over-
board the aircraft.

3.3.2.6.5 Tanks - Tanks shall be designed for vacuum filling in the field.
A pressure relief device shall be provided on the cover. Maximum operating
pressures (positive and negative) for which the unit is to be operated shall
be indicated on the nameplate.

3.3.2.6.6 Fans, pumps and control - The equipment for automatic control of
fans or pumps for forced air cooled or liquid cooled units shall be thermally
controlled with a manual override switch in parallel with the automatic
control. Contacts and sensors shall be enclosed inside the tank.

3.3.2.7 Materials quality - Molded, ceramic and laminated materials shall


be free of flaws such as cracks, delaminations and voids. Sample lots shall
be evaluated to assure flaws do not exist in the virgin material or processed
materials. Bolting and clamping shall be designed to prevent delamination or
cracking of large, thick, laminated and molded parts during installation of
parts and wiring.

3.3.3 Metals - The metal materials for each part shall be as specified (see
3.2). When a definite metal is not specified, a metal which will enable the
part to meet the requirements of this specification shall be used. Acceptance
or approval of a constituent material shall not be construed as a guarantee
of the acceptance of the finished product.

296
3.3.3.1 The following are acceptable corrosion-resistingmetals
(as distinguished from corrosion-resisting treatments).

"- a. Corrosion-resisting steel which contains a minimum of 12 percent chromium.


b. Copper
c. Aluminum
d. Aluminum alloys which do not contain more than 0.4 percent copper.
e. Brass
f. Bronze
g. Beryllium-copper
h. Copper-nickel alloys
i. Nickel-copper alloys
j. Titanium
k. Inconel

3.3.3.2 Treatments - The following are corrosion-resistant treat-


"ments that will be acceptable:

a. Sherardlzing
b. Galvanizing
c. Electrodepositing with cadmium, chromium, copper, nickel, silver, or zinc.
d. Aluminizing
e. Chromizing
f. Electrodeless nickel per MIL-C-26074

3.3.3.3 Corrosion resistance - Materials shall be of a corrosion-r-sisting


type or suitably processed to resist corrosion. Any corrosion that causes
malfunctioning of the equipment, shortening of life, impairment of use, or
impairment of ease of replacement of parts shall be cause for rejection.

3.3.3.4 Dissimilar metals - Dissimilar metals, as defined by Military Standard


MS33586, when used in contact with each other, shall be protected against
electrolytic corrosion, •ind shall have a low-impedance path to radio-frequency
currents as specified in requirement lb of MIL-STD-454.

297

"•;• • ",• - -.- - _. . .,..• .- • .. - . ... . ..-....


....... .... . . . ...........- ... "-'-" . .-.--..-.. • .-.--- .
3.3.3.5 Solder and soldering flux - Solder, when used, shall be in accord-
ance with QQ-S-571. Soldering flux shall be in accordance with MiIL-F-14256.

3.3.3.6 Screws, nuts, bolts, and washers - All mounting and terminal screws,
- nuts, bolts, and washers shall be of corrosion-resistant material or shall be
protected against corrosion. All nuts, bolts, and screws shall have standard
screw threads in accordance with NBS Handbook H28.

3.3.3., Corona protection - All mounting and terminal screws, nuts, bolts,
and washers near a high voltage part shall have rounded configuration to
eliminate corona. Screw threads shall not be exposed in parts s'.lbjected
to high field concentration.

3.3.4 Toxic materials Materials which are known to produce harmful toxic
-

"effects under any conditions, including fire, shall not be incorporated in


the design without prior approval oF the procuring activity.

"3.3.5 Standard parts - Standard parts shall be used wherever they are suit-
able for the purpose, and shall be identified on the drawings by their stand-
ard part number. In the event there is no suitable standard part in effect
on the date of invitation for bids, commercial parts may be used provided
they conform to this specification and can meet the same parts screening
procedure as for standard parts.

3.3.6 Nonstandard parts and materials - A request for the use of nonstandard
parts and materials shall be submitted to the procuring activity for approval
prior to their use in the desigrn and construction of the equipment.

3.3.7 Interchangeability - All parts having the same manufacturer's part


number shall be directly and completely interchangeable with respect to instal-
lation and performance. Changes in manufacturer's part numbers shall be gov-
erned by the drawing number requirements of MIL-D-O00,.

3.3.8 Wire - Internal wiring of a power source is considered to be all the


interconnecting wiring within the power source enclosure.

298

.. ° . • . . . . . . ..

* . _~.. • . .. ~ • .- . , ~ . _• . . ° . .
3.3.8.1 Insulated wire - When insulated wires aro used in wire terminals,
. "-' the wire shall be of the types and sizes covered in MIL-W-76, MIL-W-16878,
MIL-W-81381 or the H.V. cable criteria document. Government approval shall
be required when other types and sizes of insulated wires are used as
termi nal s.

3.3.8.2 Wire support - All wires, cables, and buses shall be supported and
arranged so that they will withstand abrasion, flexing, and vibration.
Clamping shall be such that it will not damage the insulation.

9 Thermal stress - Materials, metatls and insulations, subjected to cryo-


genic temperatures shall be of a type suitably processed to resist deformation,
cracking, or delamination when cycled from room ambient temperature to cryo-
genic temperature and vice versa, and shall maintain their electrical, con-
ducting, and insulating properties throughout the temperature range.

3.3.9.1 Resistance to deformation, cracking, and delamination shall be


required only in samples of representative size, shape and construction,
only when subject to preloads representative to those expected in service,
and only when subject to rates of temperature variation not in excess of
30 percent greater than can reasonably be expected in service.
3.3.10 Fasteners
3.3.10.1 Panel fasteners - Panels, inspection doors, and plates for all com-
Y ponents, which are subject to frequent operation and removal, shall have
corrosion-resistant fasteners conforming to MIL-F-5591, type II, style 1,
?.
class and size as required.

3.3.10.2 Electrical fasteners - Each electrical fastener, and other elec-


trical hardware shall be made of corrosion-resistant material or shall be
treated to be corrosion resistant. Fasteners (bolts, screws, studs, or
* other fasteners) shall not generally be depended on to carry current; they
shall serve merely to hold current-carrying parts (lugs, terminals) in firm
contact with each other. Where flow of current through a stud cannot be
avoided, the stud and all its associated hardware (nuts, locking devices,
washers, or other hardware) shall be made of corrosion-resisting material.
w; Positive means (such as pin,, ol- square shanks) shall be provided to prevent

299
turning of studs in their mountings when nuts are tightened or loosened;
lockwashers which depend on friction or spring action will not be acceptable
for this purpose. Unused length of threads on studs (or screws used as studs)
shall not exceed half the diameter of the stud.

3.3.10.3 Other fasteners - Each fastener (screw, stud, bolt, pin, or other
fastener) shall be equipped with a suitable locking device to prevent loosen-
!I.. ing due to vibration. Locking shall be by locknuts, castellated nuts with

cotter pins, lockwashers, lock wire, or lock plates. No swedging, peening,


or staking of parts subject to removal or adjustment will be permitted.
Lockwashers shall be captive on nuts, machine screws, capscrews, and bolts,
when the nominal size is less than 1/4-inch diameter. Fasteners and asso-
ciated hardware (nuts, locking devices, washers, or other hardware) shall be
made of corrosion-resistant material, or shall be provided with a corrosion-
resistant treatment. Self-locking nuts may be used on removable through
bolts in lieu of a lockwasher.

3.4 Alternating current generator performance

3.4.1 Design and construction - The article shall conform to the applicable
specifications and standards or to the detailed specifications.

3.4.2 Functional description - The ac generator shall provide high voltage


power to a selected aircraft load upon demand, without arcing, during ground
testing and flight operation. The ac generator prime mover shall be
an aircraft power source or an equivalent ground power unit.

3.4.3 Generator performance requirements - The generating system, including


the auxiliary components, shall perform as required herein. Unless otherwise
specified, these requirements apply at the terminals, with the prime mover
input, speed from 1.0 to 1.1 PU rpm. Operation up to 1.1 PU rpm will be
demonstrated with steady-state loads up to 1-1 PU MVA.

3.4.3.1 Speed range - The speed range of the generator input shaft will be
1.0 to 1.1 PU rpm.

300
3.4.3.2 Load - The generator shall be capable of supplying the following
loads at the input speeds and for the time intervals indicated.

3.4.3.2.1 Continuous load - The system shall be capable of supplying contin-


uously for five minutes a load of 1.0 PU MW.

3.4.3.2.2 Overload - The system shall be capable of supplying the following


overloads under the conditionis specified below:

a. 1.25 PU MVA for 10 seconds at 1.0 to 1.1 PU rpm


b. 1.5 PU MVA for 1 second at 1.0 to 1.1 PU rpm

Overload capability may be an over-current capability without substantial


over-vol tage.

3.4.3.2.3 Short circuit - For any steady initial condition within the
capability of the system, the generator shall remain substantially physically
intact following sudden application of a short circuit at the terminals.
Subsequent operation without inspection and repair shall be required.

3.4.3.3 Symmetry of construction - For all speeds and balanced loads within
the full load rating of the generator, the phase voltage unbalance shall not
exceed 2 percent. The phase separation of balanced loads shall be 1200 +12.

3.4.3.4 Efficiency - The.minimum efficiency at rated load for the generator


system (includes exciter and coolant pumps) shall be 95% at full load.

3.4.3.5 Service life requirements

3.4.3.5.1 Useful life - The unit shall be designed for a useful life,
including standby, storage and operation of 50,000 hours.

301

- 4
3.4.3.5.2 Flight line service - The unit shall operate a minimum of 100
flight readiness hours without repair or adjustment of any kind. Routine
maintenance of coolants and fluids/liquid dielectrics is permissible for
each flight.

3.4.3.6 Transient vo'tage characteristics - The average of the three phase


voltages shall remain within the limits specified in Figure G1 during and

following load and fault switching.

3.4.3.7 Voltage buildup - The voltage buildup transient shall not exceed
the limit of Figure Gl. Voltage shall recover to and remain within + 5% of
the final steady-state value, within I second maximum and shall be compatible
with system over-voltage protection limits of paragraph 3.4.3.14.

3.4.3.8 Voltage recovery time - In addition to the recovery limits of Figure


Gl,the voltage shall recover to and remain within 0.05 PU volts L-L of the
final value within one second after application or removal of a step load
starting from 0.1 PU MVA to 1.1 PU IMVA or from 1.1 PU MVA to 0.1 PU MVA.

3.4.3.9 Voltage regulation - Voltage regulation shall be +0.05 PU volts


maximum over the rated speed, power factor, and ambient temperature range
at loads from zero to 1.2 PU MVA.

3.4.3.10 Generator shock load - Sudden application or removal of any load up


to 1.0 PU load from the generator drive input at any constant input speed
from 1.0 PU to 1.15 PU rpm shall not cause the real load to exceed the average
real load by more than 0.1 PU MVA.

.1

302
3.4.3.11 Starting performance - The generator after having been stabilized
at any outside ambient frc..i -55°C to +55C temperature, shall be capable of
the following starting performance. After having the input speed brought up
to 1.0 PU rpm within a period as defined in the detailed specification, the
.generator shall, at the end of the period, meet the following requirements
under anyload up to 1.0 PU IVA:

a. It shall be within ±+0.05 Hertz of the steady state operating frequency


requirements:

1. Within 1.0 second after obtaining steady-state speed where the


ambient temperature is +50C at the beginning of the 1.0 second
period.

2. Within 2.0 seconds after obtaining stead-state speed where the


ambient temperature is -55*C at the beginning of the 2.0 second
period.

3.4.3.12 Exciter - The excitation system shall be capable of supplying steady


state excitation power. The excitation system shall be capable of rapidly
forcing the alternator field toward zero following a load loss or a short-
circuit fault. Generator start-up characteristics and shut-down characteristics
shall be considered in the excitation system design (see figure Gl). The unit
may have a power input from the airplane auxiliary power system.

3.4.3.13 General control requirements - All control circuits shall be


designed to prevent system disturbances during normal system operation. The
design shall guard against the possible effects of extraneous voltage pickup
within the system and associated wiring.

303

• .T-.
;:•.• ., "";•
.'. '.'* •,•,k•:,••,•".,
• '-.-.., .,... .- .. •.. • . •. •. . .. •. . -.... . ......
120%

w
MAXIMUM LIMIT
0
:,,,, • w 110%

•z• TRANSIENT
•.. .•CONDITIONS O (105% NOMINAL)
z (NOMINAL)
S.100%
(95% NOMINAL)

9c'

.•..-..VOLTAGEBUILDUP

0 0.25 0.5 0.75 1.0 1.25 1.5 1.75

TIME FROM ONSET OF TRANSIENT, SECONDS

Figure G 1: Envelope of AC Voltage Transient

304
S•
S. . . . .. .• .. .. . . • .- .;-: .
r- . -.. o .-. .- 1 -.- ,• -. -. --.-- -. '.j . - .
-;77-

3.4.3.14 Control functions - The term "relay" is used in this section to


"*-" simplify description of function, and does not necessarily refer to an electro-
mechanical device. The following control functions shall be provided:

a. Generator field control and indication


b. Anti-cycling and lockout control
c. Power ready relay control

3.4.3.14.1 Generator field control and indication (GCR) - A relay shall be


provided to make and break the generator exciter field circuit or voltage
regulator power supply circuit. This relay shall be operated by: 1) internal
protective circuits, and 2) external safety switches.

"Atime delay shall be provided so that this relay is tripped 2 to 3 seconds


following actuation of the safety switches.

3.4.3.14.2 Anti-cycling and lockout control - The Controi System shall


contain suitable lockout circuits to prevent cycling of the generator field
control if a system fault exists and an external control switch is held in the
"close" position.

Anti-cycling relays shall be provided to prevent cycling of circuit breakers


and contactors whenever more than one switch is held in the "close" position.

'A

* 1

3
.1

-I O

"•
,. .•',',:•
- , - ,,-,,,
;,,!. -,-. .,, .,., ... -'- --.. ,-,---'".-,-- .-.---- . , .-. .A-, .•- , - ,- • - - -.- T:
Lz'1
L!.

r1,•

3.4.3.14.3 Power ready control - The power ready control shall inhibit the
closure of relays or circuit breakers if the power quality of the power source -
generator or external power supply, is beyond the abnormal power quality limits.
"Over voltage, under voltage, over frequency and under frequency shall be the
determining factors of power quality detemination.

3.4.3.14.4 Underspeed trip circuit - The underspeed trip circuit shall be


activated by a contact type swi tch. The contacts of the underspeed switch
shall not be subject to contact chatter or mechanical failure (such as
fatigue failure at soldered connections) when oper'ating in a vibration
environment.

3.4.3.14.5 OverspeeJ/underspeed - A device shall be included in tkie power


input to monitor rotor speed. The output from this device shall operate a
protection circuit in the Generator Control Unit to provide overspeed and
underspeed protection.

3.4.3.14.6 Charge pressure switch - A charge pressure switch shall be


provided to actuate warning lights on the airplane instrument panel when
the oil pressure or coolant pressure reaches the minimum safe value. The

306
warning light and all associated electrical wiring will be furnished as part
of the electrical power system.

The switches shall be of the contact type. The contacts of the switches
shall be open during normal operation and shall not be subject to contact
chatter when operating in a vibration environment.

3.4.3.15 Magnetic sump plug - A magnetic oil-sump plug shall be provided


in the fluid circuits to attract any loose magnetic particles. The plug
shall be designed such that the magnetic particles can be inspected without
loss of sump fluid. ThP magnetic field of the plug shall be in a direct path
of the fluid flow.

3.4.3.16 Lubrication and cooling system - The generator assembly shall


include lubrication and cooling systems which shall satisfactorily lubricate
and cool the generator under the operating conditions specified herein.

3.4.3.16.1 Oil, gas, and other fluid coolant filtration - Oil and coolant
filters shall be incorp'rated into the charge systems of the generator if
oil filtration is required for proper operation. The filter shall perform
as required by MIL-F-5504.

The oil and coolant filter shall have a minimum service life of 100 hours
operation. An external indication of excessive pressure drop shall be
provided. The filter shall be arranged such that the filter element can be
removed and replaced without removing any other part of, or connection to,
thc si* ':ulant circuits.

M,4.3 16.2 "e)Ws - The generator shall have seals for holding oil and
oter Fluid coolant leakage to a minimum. Leakage shall not exceed the
fA Iowi ng:

a. Input shaft seal leakage 1 cc/hr

C b. Generator external leakage at Oil wetting may occur, but no drops


static seals shall form

307

•; ' • '• • ,T ,') -.---..- .- .-


;-.,•.• .',: * *...
,5----.'
."• -. ,..-.:."-•• . ' ,.. --. - -. , -
c. Static (standby) total leakage: Same as above at 6 - 10 psi

d. Static total leakage at 6* head: 1 cc/hr

3.4.3.16.3 Reservoir - The generator assembly shall have an integral reser-


voir and self-sealing fill overflow boss. Visual means shall be provided to
indicate both "full" and "refill" oil and other fluid coolant levels while
the generator is at the ground installation attitude. For ground installa-
tion the generator center line may be inclined up or down 40 from the hori-
zontal. A drain port shall be provided to permit draining of the reservoir
and drive case.

3.4.3.17 Helium - Superconducting generators shall use liquid helium for


cooling the superconductor. Helium boll-off during Dewar charging, standby,
and system operation shall be vented overboard or reclaimed. Provisions shall
be made to prevent accumulation of helium inside any airplane compartment
while on the ground or in flight.

3.4.3.17.1 Detectors - Helium leak detectors shall be placed on-board the


airplane in critical high voltage areas to detect and send warning signals
to the control panel In :ase of helium leaks.

3.4.3.18 Electrical components

3.4.3.18.1 Explosion-proofing - All electrical components, except hermeti-


cally sealed or potted units, shall be explosion proof as defined in MIL-STD-
810, to prevent ignition of any explosive mixture which may surround the prime
mover.

3.4.3.18.2 Electrical connector - All electrical leads shall terminate in


electrical connectors.

*-, 308
-. ,. ' ,- •'!.r.
,W tj;• . .*;,• :f . rr.*
;.,,• ' ,, -,,.••.- X,*
5 .' - -,-,-. = " -• ,. 4 - - • . - .-.
V-, , -*• -' .. .. ' - -
materia. l. Suitable- b s-hal be providedbetweentermina.l. T.e•n.. -.

.h e connecto
sr b r eranh o output phases,
•, ° .'

diecl ove"r a t.43.1


nteutral termnal The gaeneratnar cousnngtr shall berofvide
.., The ternal housi ng shall be of a fire-resistant, e
extinguishing self i h
mterial . Suitable barriers shall be provided between terminals. The con-
Snectors shall be arranged to positively prevent routing of the line leads
~. ~ 3.4.3.19. Main terminal blok ngcoe
Th - main h ousi
verminale ng alllroide
n-sh
directly
3 . over the neutral terminal. The generator connectors shall b, of the
type described in the High Voltage Connector Criteria Document, Appendix D.
The connectors shall be permanent.y marked Ti, T2, etc., for the output phases,
•":"and N for the neutral.

3.4.3.19.1 Maitn terminal housing cover - A cover, made of non-metallic,


fire-resistant, self-extinguishing material, shall be provided for the main

iteminal housing. These termitnal covers shall be rmovable


t nd replaceable
from either side of the generator without disturbing the lay of the cables to
the t nals.
mae

4
*~,3.4.3.19.2 Connector - All electrical connections to the generator, other
than the 3 phase, four-wire main output connections, shall be low voltage
connectors.

3.4.3.20 Solid-state devices - Exciter solid-staee devices shall


preferably be of a standard comlercal type. Design shall be such thac even
S3during system fault conditirs the current and voltage to which the devices
are subjected does not exceed 60i of their rating; a suitable supprssion
3 device may be used to meet this requircrnent. The generator shall not be

further damaged as a result of a solid-state device failure.

3.4.3.21 Maintenance - The design of the generator shall be such as to


facilitate servicing, replacement and repair. Replacement of the exciter
output solid-state device shall not require balancing of the rotor, or
cutting and rebrazing of the leads.

3.4.3.22 Position - The power source shall .meet the performance


S~requirements of this specification when operating under conditions a.
4,- through d. below:

309
a. Level position with the power source inclined up to 30 to either
side . . . . I ndefi nitely.

b. 00 - 600 climbing or diving angle with the power source inclined •'
to either side . . . . 60 seconds.

c. Negative 1.0 g operation . . . . 60 seconds.

d. -6g maximum . .. . 5 seconds.

3.4.4 AC generator control unit requirements

3.4.4.1 Cooling air - No cooling air will be provided.

3.4.4.2 Operating position - the unit shall function properly regardless of


orientation.

3.4.4.3 Circuit separation - Control circuitry should be ele:trically ,


functionally and physically isolated insofar as practicable from the voltage
regulator and protective circuitry. input and sensing protection and control
leads should be separated from the voltage regulator connections. All power
required for generator excitation under normal load, overload aprd fault
conditions shall be supplied to the voltage regulator by the generator or
dedicated power supply.

3.4.4.4 Voltage regulator section.

3.4.4.4.1 Voltage sensing - The voltage regulator shall sense and regulate
the average of the three phase voltages. High-phase "take-over" or "limiting"
shall be provided, if required, to limit the highest phase voltage under
unbalanced load or fault conditions to the limics of paragraphs 3.4.3.6
through 3.4.3.11.

3.4.4.4.2 Excitation power - All power required for jenorator excitation


under nomal load, overload and fault conditions shall be supplied to the

310
~~S~~V&ThW.~~ ~ * -n -. - -. -.
- - -. - *
--- - k & * * C~~

voltage regulator by the generatoror dedicated power supply. See


"paragraph 3.4.3.12.

3.4.4.4.3 Stabilizing - The voltage regulator shall be self-stabilizing.


Feedback and/or stability circuits required to obtain system stability shall
be contained within the voltage regulator. No generator stability windings
shall be required.

3.4.4.4.4 Power and fault current limiting - The generator input power and
fault current limiting circuit, if required to meet the requirements of para-
graph and 3.4.3.2 shall be contained within the voltage regulator section.

3.4.4.4.5 Voltage adjustment - An internal adjustment shall be provided to


permit the point of regulation no-load voltage to be adjusted in increments
of not more than 50 volts. The setting means shall be so designed and con-
structed that it will not be displaced under any of the vibration conditions
specified in paragraph 3.6.7.

3.4.4.4.6 Useful life - The unit shall be designed for a useful life o.
50,000 hours operation, shelf and standby.

3.5 Magnetohydrodynamic generator

3.5.1 Design and construction - The article shall conform to the applicable
specifications and standards or to the detailed specifications.

3.5.2 Functional description - The magnetohydrodynamic (MHD) generator shall


provide a specified voltage, direct current, power load upon demand
without interelectrode arcing, during ground testing and flight operations.

3.5.3 Performance requirements - The generating system, including the


auxiliary components, shall perform as required herein. Unless otherwise
specified, these requirements shall be at the power output terminals.

3.5.3.1 Load - The generator shall supply the following loads for the time
intervals indicated.

311

i•' '•.' , ,/ -' ,''''• '", '• '•• .', .;' ',• , '.• ." ,". " " ",.-" . "'. .' "".-
3.5.3.1.1 Continuous load - The system shall be capable of supplying
continuously for five minutes, to a fixed load resistance 1.0 ± 0.1 per unit MW.

3.5.3.1.2 Overload - The generator shall be capable of supplying the following


overloads under the conditions specified below:

1.25 PU MW for 10 seconds. Increased load will be accomplished


by decreasing load resistance.
1.5 PU MW for 1 second.

3.5.3.1.3 Short circuit and open circuit - From supplying continuous rated
power at rated voltage the generator shall be capable of withstanding a short
circuit or open circuit for a period of 1 second without harm to the
y
generator
or protection devices. The generator shall be protected from open/circuit and
short circuit conditions.

3.5.3.2 Efficiency - The ratio of thermil power input to electrical power


output at rated load for the MHD generator system (including auxiliary
supplies and equipment) shall be greater than 0.20.

3.5.3.3 Service l-,fe requirements

3.5.3.3.1 Useful life - The unit shall be designed for a useful life,
including shelf, standby and operation, u1 50,000 hours.

3.5.3.3.2 Flight line service - The unit shall operate a minimum of 100
flight readiness hours without major overhaul. Routine maintenance of
coolants, gaseous/liquid dielectrics and channel are permissible for each
flight.

3.5.3.4 Voltage requirement - The required voltage shall be 1.0 ± 0.05 PU


volts at 1.0 + 0.1 PU load current.

312
. .~~~* ...
_.. .. ,,
.
,• € . • ° .
. ...
, ,. ,
. .
. . ....
. °. - ,
.* .. * .
• .. A. ., • ..
....
• . ° , . . . .
,-
-- :
ý'.

:...j*, 3.5.3.4.1 Voltage


With a constant resistance load, the load vcItage
-

"shall rise and remain within 1.0 ± 0.05 PU volts of the final steady state
voltage 1 second after start-up command. The system voltage limits shall
he compatible with the system over-voltage, under-voltage protection
devices of paragraph 3.5.3.1.1.

3.5,3.4.2 Voltage recovery time - The generator shall recover and remain
within 1.0 ± 0.05 PU volts within one second after application of a step
load from 0.1 PU to 1.0 PU MW.

3.5.3.4.3 Transient voltage characteristics - The load voltage shall remain


within the limits specified in FigureG2during and following load and fault
switching.

3.5.3.5 Starting performance - The generator system when stabilized at any


external temperature of -55 to +850 C shall perform according to all other
requirements defined in paragraph 3.5.

3.5.3.6 Magnet - All power required for the generator may(net shall be
supplied by in auxiliary airborne power source or switched ground support
power supply.

3.5.3.6.1 Cryogenic magnets - The cryogenic magnet shall use helium as a


coolant. The Dewar shall be active during flight and ground tests and
instrumentation and monitors shall be active to assure tfe cryogen is in a
fluld state. Helium bubbles are unacceptable in the magnet.

3.5.3.6.2 Seals - The magnet, plt.bing and Dewar shall be sealed to


minimize leakage. Coolant leakage shall not exceed 1 cc/hr at standard

temperature and pressure for the total system.

4T,

313

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"•"'" . "": " " " .9 ""'"
. ""''".""" "" """""9 " 9"""
...... . . . . . . . """"'"""'''
. . . . . . "i"
. .. """
IL

131
3.5.3.6.3 Exhaust gas - Expended helium and other gases shall be ported
overboard.

3.5.3.6.4 Magnet start and stop - The magnet excitation shall be applied in
a time-linear fashion with no impulses. The radiative effects of the magnetic
field increase/decrease shall be contained within the magnet. External
magnetic field fringe effects shall be less than that stated for the electro-
magnetic compatibility limits; see paragraph 3.5.3.6.5.

3.5.3.6.5 Shielding - A magnetic shield capable of reducing the channel


magnetic field to 100 gauss outside the channel shall be proved to protect
sensitive instrumentation and electronic circuitry located within one meter
of the magnet. Conducted and radiated interference produced outside the
shield by the starting, stopping or operation of the magnet shall not exceed
the requirement of Specification MIL-STD-461.
3.5.3.6.6 Retention of magnetism - The magnetic output shall not deteriorate
more than 1% during the required life of the MHD generator due to age or as the
result of handling, shocks, system faults, material deterioration or normal
usage.

3.5.3.7 Tankage and storage - Tankage and stored materials, including fuel,
shall be stored in containers designed to withstand hydrostatic pressure
2-1/2 times either the maximum operating pressure or pressure resulting from
any single possible malfunction or transient.

3.5.3.7.1 Pipe, hose, and fittings - Pipe shall conform to ASTM Designation
A120, with fittings that conform to ASTM Designation A181. Pressure piping

systems shall be in accordance with ANSI B31.1.0 and B16.5, as applicable.


Hose and hose fittings shall be used with piping systems where there is rela-
tive motion between parts. The hose and fittings shall be selected and sized
for the pressures involved. The use of snap rings in conjunction with petroleum
products liquid lines where snap ring failure would present a fire hazard is

".3

.'_: 315
i
~.....-
°l .°-,.•-.-.•..........................-..*o..°......o.. • .- , ... .........

• ,# • ,'•€, .'. . • -• . . - -. .-. . . - 4 . -° .' • °° .• . °o • °. -. = , °. ' *." "••°


-. ' •,,-°.•.- 4..- • ... * -o ••m .•"•••- -o •-- • 'r -• • • - -.- .. - •w. - - - --. --

prohibited. Piping which connects liquid systems shall be arranged to avoid


any air pockets or undrained traps and shall have provision(s) for venting
air after any part, subassembly, or component changeouts are made. All drain
piping shall terminate through the side of the base of the set with an
installed valve threaded for connection of an external pipe.

3.5.3.7.2 Pressure-vacuum bleeder - A pressure-vacuum bleeder device shall


be set to operate at the maximum operating pressure (positive and negative)
indicated on the nameplate.

3.5.3.7.3 Monitor - The monitor and display subsystem shall have provisions
for signal processing, remote sensing, and display of information on an
airborne display unit.

3.5.3.8 Cooling air - Cooling air will be provided during flight by RAM air,
at temperatures as shown in Figure G3. On the ground,air will be provided by
fans at temperatures as shown in Figure G4. This cooling air will under
certain operating conditions contain small amounts of runway debris (sand,
slush, rain).

The rated air flow will be defined in the detailed specification. The vendor
proposal shall provide a rating chart showing cooling air flow requirements
over the operating altitude and temperature ranges. The cooling air outlet
duct shall be provided with a clamp attachment.

3.5.4 Control requirements - All control circuits shall be designed to


prevent system disturbance during normal system operation. The design shall
guard against the possible effects of extraneous voltage pickup within the
system and associated wiring.

316
35 (MAXIMUM SPEED
OF.92 MACH)

.20

30

25

"io _ _ _ _ _-__ _,__ _

I15

A103IF

• 10
* • :'_.'- -. , . -". - ..- :- -. . .'. -. . . .. 05:--.-92•
,- . ..AC.-H- .•). -. .

OOF I
100O1: 13OOF 10O1=

(AIUTEPMPERATURE

Figure G3. RAM Air Temperature L~imits

317
10

.1U

j- U.

x5
Lu

F-
o

-1I II

-65OF OIF 100OF 130OF

FigureG4: BlowerAir Temperture Limits

4.

318
3.5.4.1 Control function Four control functions shall be provided:
L:..
-

a. MHO system control


b. Magnetic field protection
c. Fault isolating control
d. Power ready control
".1.

3.5.4.1.1 MHD system control - A controller shall be provided to turn the MHD
generator "ON" and "OFF," to operate the system in the STANDBY and CHECKOUT
modes, and provide protection for magnet current interruption during MHD
generator operation.

3.5.4.1.2 Magnetic Field protection - A relay shall be provided to the


generator magnetic field control circuit. This relay shall be tripped by
internal protective circuits.

3.5.4.1.3 Fault isolation control - A relay shall be provided to transfer the


-* magnetic field circuit from airplane power supply to an airplane emergency
supply system should the airplane power system sustain a fault.

3.5.4.1.4 Power ready control - The power ready control shall inhibit the
closure of relays or circuit breakers if the power quality of the airplane

power system, external power source or generator is beyond the abnormal power
quality limits. Overvoltage and undervoltage shall be the power quality
determining factor.

4.6

3.5.5 Cooling - The generator cooling system shall satisfactorily cool the
generator under operating and standby conditions specified herein. Coolant
filters shall be incorporated into the charge system of the generator (see
"paragraph 3.4.3.16.1). Seals and reservoir shall meet the requirements
specified in paragraphs 3.4.3.i6.2 and 3.4.3.16.3.

3.5.6 Helium - The helium boil-off during charging, standby and flight shall
meet the requirements of paragraph 3.4.3.17. Monitor, detector, and displays
shall be as specified in paragraph 3.4.3.17.1.

a.31

4 319

!,'L•.•.•o..•,...,
.,....•,.. ,. . . . . . ~. .* -. - . . .
3.5.7 MHD proce~ssing and control unit - An electronic processing and
control unit shall be developed to sense and send control signals to the MHD

generator system control, see 3.5.4.1. This unit shall be desinned to


receive inputs from the coolant loops, fuel tanks, seed supply, input air
louvers, load voltage and current. The processor shall react to protect
the MHD generator and load equipment against load system faults (open or
short) or sustained transients as well as to govern normal operation. A
direct interface shall be made to the airplane monitor and display unit.

3.5.8 Monitor and display unit - Signals from several sources shall be condi-
tioned for display on visual electronic scopes or monitored for go, no-go panel
"lights. Items that shall be displayed include but are not limited to:

Load voltage
Load current
Load power
Fuel metering
Seed metering
Coolant temperature and level
MHD magnet temperature
MHD channel temperature
MHD magnet current
Combuster temperature
Propellant levels

3.5.9 Exhaust gases - MHD exhaust gases shall be ported in order not to
impinge upon airplane structural surfaces or edges during airplane standby,
during takeoff or landing, or flight.

3.5.9.1 Thrust - Exhaust gases shall be ported in a manner to give minimum


* torque to the normal airplane thrust pattern.

S-320
3.6 Operational conditions - The power source shall be designed to provide
rated output under the following conditions or combination thereof,
listed in the following subparagraphs.

3.6.1 Temperature and altitude - The power source shall meet the requirements
of paragraph 3.5.3 when subjected to the following ambiept temperature range:

a. Operating - The equipment shall be capable of operating at temperatures


"between -20 0 C to 55 0 C at pressure altitudes from 1,000 feet below sea level to
40,000 feet above sea level. It shall be capable of operating for one five-
minute cycle in an ambient temperature from -55°C to 710 C at altitudes 1,000
feet below sea level to 40,000 feet above sea level. It shall be capable of
withstanding a pressure drop from 15,000 feet altitude to 45,000 feet altitude
in 15 seconds while operating.

b. Non-operating - The equipment shall be capable of continuous exposure to


ambient temperatures from -55 0 C to +71 0 C at pressure altitudes from 1,000 feet
below sea level to 40,000 feet above sea level.

c. Cycling - The equipment shall be capable of multiple 5 minute operating


cycles at full load.

3.6.2 Humidity - The equipment shall be capable of operating at relative


humidity ranging up to 100 percent, including conditions wherein condensation
will take place on the equipment.

3.6.3 Sand and dust - The equipment shall be capable of operating under
conditions of airborne sand and dust particles.

3.6.4 Salt spray - The equipment shall be capable of operating in an atmos-


phere containing salt-laden moisture.

3.6.5 Fungus - The equipment shall be capable of operating when exposed to


fungi as encountered in tropical areas.

321
k'.gM11

3.6.6 Shock - The article shall be free of leaks, cracks, bursting, or bulging
of the cases when t2sted as specified in 4.11.7.

3.6.7 Vibration - When the article is tested as specified in 4.11.8


.' there shall be no lea!*ge of fuel, coolants, or seed materials and no evidence
of other physical damage such as cracks, bursting, or bulging of the structure.

3.6.7.1 Airplane vibration - The power source system and ancillary components
shall be subject to the airplane vibration during ground standby, take-off and
landir,, and flight.. Vibration modes and tolerances requirements are defined
in the detailed specification.

3.6.7.2 MHD generator vibration - Vibration transmitted from the MHD generator
to the airplane structure shall be limited to the values defined in the detailed
specification. These parameters shall not be exceeded due to a short circuit
or fault imposed upon the generator.

3.6.8 Flammability - When the article is tested as specified in 4.11.9, there


shall be no evidence of violent burning which results in an explosive-type fire,
and the coating material used on the article shall be self-extinguishing. The
article shall not be considered to have failed, in the event that it is consumed
by the applied flame, unless dripping of flaming material or an explosive-type
flame has occurred. The article shall be considered to have failed only if an
explosion or dripping of flaming material occurs, an explosive-type flame is
produced, or if visible burning continues beyond the allowable duration of 3
minutes after removal of the applied flame. Material will be considered
self-extinguishing if the following conditions are met:

a. The duration of visible flame does not exceed 3 minutes after removal of
the applied flame.

b. There is no explosion, nor any violent burning which results in an


explosive-type flame.

c. There is no dripping of flaming material from the power source under test.

322
. .. . . . I.. . *... . **
,• - ... . .. :... ,-.-..- -.-.
. . . . . . .1
*, !•. 3.6.9 Nuclear radiation - Exposure limits to nuclear radiation shall be
specified in the detailed specification.

3.7 Lifting, moving, and jacking facilities

3.7.1 Safety factor - Lifting, moving, and jackirg facilities shall be designed
to provide a safety factor of 5. This tafety factor is the ratio of the ultimate
stress of the material used to the working stress. The working stress is the
maximum combined stress developed in the lifting facilities by the static load
of the component being lifted.

3.7.2 Lifting facilities - Lifting facilities shall be provided for lifting


the cover separately, and also for lifting the internal assembly from the housing
using four lifting cables.

Facilities for lifting the complete article (with the cover securely fastened
in place) shall be provided. Lifting facilities shall be designed for lifting
with slings at a maximum angle of 30 degrees with respect to the vertical. The
bearing surfaces of the lifting facilities shall be free from sharp edges.

3.7.3 Moving facilities - The base of the article shall be mounted on a frame
of heavy plate or shall have members forming a rectangle that will permit rolling
in the directions of the centerlines of the segments.

3.7.4 Jacking facilities - Jacking facilities shall be located near the


extreme ends of the junctions of tihe case.

3.7.5 Mounting - The points of support shail be so that the unit will with-
stand the variable orientation of the airplane.

3.7.6 Mounting studs - When specified (see 3.2), external mounting studs shall
be provided with a flat washer and locknut, or with a flat washer-, lockwasher,
and a nut.

323

•' ', , \• ,• •' -,-.-,-,-.


-•-' .- '. '.', -.- .. . ..- , .. . .
,... . . . •,. .-.. ,'... , • . -. .,.
3.7.7 Mounting and terminal screws and mounting inserts - Screw.threads shall
be class 2A or 2B, as applicable (see 3.2), in accordance with Handbook H28.
External screw threads, class 2 fit, shall, after receiving a finish, be capable
of accepting a nut of class 2B fit and internal screw threads, class 2 fit,
shall, after receiving a finish, be capable of accepting a screw of class 2A
fit. Maximum installation torque shall be as specified in the detailed speci-
fication. Nuts shall run down to within two threads of mounting surfaces.

3.8 Electrical construction

3.8.1 Internal wire leads - Internal wire leads shall be attached to the
internal component terminals or case by soldering, welding, brazing, or other
method (e.g., lead-sweating on nylon-coated wires) in such a manner as to pro-
vide adequate electrical connection and mechanical strength. Where soft solder
is used to provide the electrical connection, wire leads shall bc anchored
mechanically.

3.8.2 Wire bundle ties and clamps - Wire bundle ties shall have the knots
either burnished or enameled. (See "High Voltage Design Guide: Aircraft".

3.8.3 Terminals

3.8.3.1 Solder terminals - Solder terminals may be of any shape and shall be
capable of complying with solderability requirements of this specification.
The height of the solder terminal shall be considered as the maximum distance
from the terminal mounting surface to the highest point, including the addi-
tional height obtained if semiflexible terminals are straightenpd. (It is not
intended that the "hook" in the hook-type terminal be straightened from its
normal hooked position). The.type of terminal and the maximum size ,f wire
which the terminal will accept externally shall be as specified (see 3.2).

324
-" ,.-,,,, -. ,.... -- ..- ..- .. . . - .. . . .- . . .o - . .. . , • . ,.. " .
3.8.3.2 Case as terminal - When the case is used as a terminal, any protective
coating applied to the mounting surfaces shall be such as to provide a direct
conducting path for an electric current from the case to the surface on which
it is mounted.

3.8.3.3 Screw terminals - When specified (see 3.2), external screw terminals
shall be supplied with two nuts, two flat washers, and one lockwasher. For
cased units, the height of the terminal assembly shall be the distance from
the free -nd of the screw to the terminal mounting surface. The type of
terminal, size of screw thread, and the exposed length of threads + 0.062
inch shall be as specified (e.g., screw, 0.164-32 UNC x 0.375) (see 3.2).

3.8.3.4 Terminal strenjth - When the article is tested as specified in 4.12.5,


there shall be no evidence of loosening or rupturing of the terminals, Gr other
m.,;iianical damage. Bends shall not be considered as damaged unless surface
cracking is evident. Except for flexible leads, there shall be no rotation of
the terminals. Rotation of the external portion of the metallic portion of a
"hook" type terminal exceeding 10 degrees shall not constitute a failure.

3.8.3.5 Bushings - The insulation level of line bushings shall be equal to


or greater than the insulation level of the windings to which they are con-
nected (see 4.12.6).

3.8.3.6 Terminal insulators - Terminal insulators shall be epoxy, glass, or


ceramic.

3.8.3.7 Corona protected bushing insulator - When specified (see 3.2), termi-
nals shall be supplied with a corona suppressor where the terminal and terminal
, hardware are shielded by an angle of at least 3.0 degrees by a corona suppressor
cavity. Terminal hardware shall consist of two nuts, one flat washer, and one
lockwasher, or shall consist of one flat washer, one lockwasher and one cap
screw. The terminal post shall not have external threads above the corona
suppressor in the bushitng. Terminal post finish shall be 100 microns or
smoother. The height of the terminal assembly shall be the distance from the
top of the corona suppressor to the terminal mounting surface. The type of
terminal shall be specified (see 3.2).

325
-T

3.8.4 Connectors Connectors shall be hermetically sealed, circular threaded,


-

high voltage with solder or brazed contacts.

3.8.5 Solderability - When the article is tested as specified in 4.12.7, it


shall meet the applicable criteria for terminal evaluation in the test method.

3.8.6 Resistance to soldering heat - When the article is tested as specified


in 4.12.8, there shall be no softening of the insulation or loosening of the
windings or terminals.

3.8.7 Potting, filling, or encapsulating material - The amount and coverage


of potting, filling, or encapsulating material used shall be essentially the
same for all units of a specified design. Potting, filling, or encapsulating
material shall not flow from the case of the article during any of the appli-
cable tests.

3.8.8 Grounding - The article shall be grounded by bonding the case(s) to the
airplane structure. A common point ground shall be specified for bonding the
power source and load in a manner to prevent circulating currents in the ground
path, protect the equipment from electromagnetic pulses and lightening, reduce
electromagnetic interference, and prevent electrostatic discharges harmful to
personnel. A ground path shall provide a path with a current-carrying capacity
equal to or greater than that of the input and output conductors.

3.8.9 Surge arresters - When specified, a surge arrestor ground pod consisting
of a tank ground pod, mounted near the high voltage terminals shall be available
for surge protection.

3.8.10 Power cable clamping - Power cables shall be bundled and clamped in
place at one meter intervals to avoid a whipping action during short circuit
on sudden load application. Cable clamps shall not crush or distort the cable
insulation (external or internal) _Yet hold the cable firmly in place. Cable
clamps near high voltage shielded or unshielded cables shall be insulated, and
all metal portions of the clamps shall be grounded. Metal edges shall be
chamfered to eliminate voltage stress at the edge of the clamp.

326
7, . . . . . .
3.8.11 Weight, size and configuration. The maximum allowable overall
dimensions, general configuration and weight (dry and operating) of the complete
power source with all attached accessories shall be as specified in the detailed
specification (see 6.2).

3.9 High voltage design and test.

3.9.1 Insulation resistance. When measured as specified in 4.13.1, the


minimum insulation resistance shall be greater than the value specified for the
insulation system in the applicable specification.

3.9.2 Dielectric withstanding voltage. When tested as specified in 4.13.2,


there shal be no evidence of arcing, flashover, breakdown of insulation or
damage.

3.9.3 Partial discharges (when specified, see 3.2). When tested as out-
lined in 4.13.3 or as specified (see 3.2), the partial discharge maximum magni-
tudes shall not exceed the values defined in the detailed specification for each

V component when tested at rated voltage.

3.9.4 Pulse. When tested as outlined in 4.03.4 or as specified (see 3.2), pulse
voltages shall have a wave shape as defined in 4.13.4. Pulse tests sha"l te made without
excitation.

3.9.4.1 Terminals not being tested. Inputs to low voltage instrumentation and
control equipment shall be grounded during pulse tests.

3.9.5 Electomagnetic compatibility. The unit shall be designee- to minimize the


generation of electromagnetic interference. Enclosed case construction shall provide
continuity of electrical shielding with a low radio frequency impedance path to ground and
ac.oss all mechanical discontinuities. Conducted and radiated interference produced
outside its physical envelope by the operation of the unit shall not exceed the
requirements of Specification MIL-STD-461.

327
3.10 Life - The unit shall be so designed that when operating under any
temperature or altitude condition indicated by the detail specification, the useful
life of the unit shall be at least 100 hours operating full load, in a period
of 5 years.

3.11 Reliability - The requirements of MIL-STD-785 shall apply. Reliability


shall be considered as a design factor on an equal basis with performance,
weight, etc. Based upon a best available knowledge of component reliability
characteristics, the design safety factors used, arnd tCie operating conditions
* specified herein, the mean-time-between-failure of each major system component
shall be calculated and tnis information shall be presented with the vendor's
* design proposal.

3.1.l Reliability plan - The vendor shall submit with the design proposal
the following data:

a. Description of the reliability organization, and of the system used to


collect and analyze data.

b. Methods of analyzing field data and impiementatiun of corrective action


when the products do not live up to expectations.

c. A plan to accumulate and evaluate failure data during the production


run on the hardware.

d. Program plan for scheduling corrective action for failures detected in


the production hardware.

e, Preliminary reliability assessment of the system. This presentation shall


include failure mode and effects analysis of the major functions of the equipment.

f. Overall program plani encompassing the development, production and post-


production phases.

g. Schedule for updating the expected reliability type reports such as failure
modes and effects analysis, etc.

328
.', • -. .- . . *-.
. . . . *
tI,

-,• ,**.-'" 3.12 Safety - The vendor shall conduct an active system safety program during
the design anu development of the electrical power source system. The system
safety program shall have the primary objectives of (1) identification, (2) eva-
luation, and (3) resolution of hazardous events within the electrical power
system. Hazardous events are defined, in the system safety context, as those
fault modes, special circumstances, etc., which result in injury to personnel
or damage to equipment.

3.12.1 Safety analysis - The vendor shall conduct a preliminary safety analysis
to identify and evaluate the hazardous events which may occur in operation and
maintenance.

3.12.2 Hazard resolution - Hazardous events shail be resolved by design in


accordance with MIL-STD-882; Appendix A shall apply for MHD generator.

3.12.3 Safety documentation - A preliminary safety analysis shall be provided


with the proposal and periodically updated at least semiannually for the life
: ", of the contract.

3.13 Maintainability- - The requirements of MIL-STD-470, MIL-STD-471, and


MIL-STD-472 shall apply. :Iaintainability shall be considered a parameter in
the design of the equipment. The design shall provide for rapid accomplishment
of inspections, operational testing, malfunction detection and isolation,
removal, installation and shop -epair with a minimum expenditure of time,
skill and test equipment.

"329

-. • • " o . °. . ° -• . . - .• • . .•. S *
3.14 Marking - Power sourcds" shall be marked with the military part number,
manufacturer's part number, manufat .rer's code symbol, terminal identification
(circuit diagram where space permits) and date code and lot symbols in accor-
dance with method I, MIL-STD-1285. Markings shall remain legible after all
tests. Key markings of a classified nature shall not be included.

3.15 Safety wiring and staking - Accidental loosening of screws and screw
parts and other connections shall be prevented by safety wiring (0.032 inch
minimum outside diameter) where practicable, by staking, or other approved
methods.

3.16 Workmanship - All machined surfaces shall have a smooth finish and all
details of manufacture, including the preparation of parts and accessories,
shall be in accordance with the best practice for high quality electrical
equipment. Particular attention shall be given to neatness and thoroughness
of soldering, wiring, impregnation of coils, marking af parts, plating, lac-
quering, riveting, clearance between soldered connections, and ruggedness.

*. 330
-da

". .. . . """"
. .. - ÷'"" '>:""*"""•"'"
. ." " "; " "" " " ".. "-:L-."•_i
4.. QUALITY ASSURANCE PROVISIONS

4.1 Responsibility for in3pection - Unless otherwise specified in the contract


or purchase order, the supplier is responsible for the performance of all
inspection requirements as specified herein. Except as otherwise specified in
the contract or order, the supplier may use his own or any other facilities
suitable for the performance of the inspection requirements specified herein,
unless disapproved by the Government. The Government reserves the right to
perform any of the inspections set forth in the specification where such
inspections are deemed necessary to assure supplies and services conform to
prescribed requirements.

4.1.1 Test equipment and inspection facilities - Test and measuring equipment
and inspection facilities of sufficient accuracy, quality, anJ quantity to
permit performance of the required inspection shall be established and
maintained by the inspection facility. The establishment and maintenance of
a calibration system to control the accuracy of the measuring and test equip-
•..-. ment shall be in accordance with MIL-C-45662.

4.2 Classification of inspection - The inspections specified herein are


classified as follows:

a. Materials inspection (see 4.3).


b. Qualification inspection (see 4.5).
c. Quality conformance inspection (see 4.6).

4.3 Materials inspection - Materials inspection shall consist of certifica-


tion supported by verifying data that the materials listed in table Gl used
in fabricating the power source, are in accordance with the applicable
referenced specifications or requirements prior to such fabrication.

4.4 Inspection conditions - Unless otherwise specified herein, all inspections


shall be performed in accordance with the test conditions specified in the
"GENERAL REQUIREMENTS" of MIL-STD-202, MIL-STD-454 and MIL-E-54WO.

331

44*-..
. . -. . ,,.-... . .
-,*, .. ..... . ..-
TABLE G1. Materials Inspection

REQUIREMENT
MATERIALS PARAGRAPH APPLICABLE SPECIFICATION

Insulating material:
Laminated phenolic 3.3.2.1 MIL-P-997, L-P-513,
MIL-P-15037, or MIL-P-15047

Molded phenolic or
melamine - 3.3.2.2 MIL-M-14

Ceramic (external use) - 3.3.2.3 MIL-I-lO

Laminated Plastic Sheet - 3.3.2.4 MIL-P-18177

Coolants 3.3.2.5.1 MIL-L-7818

!nsulating gases 3.3.2.6 BB-S-1419

Dissimilar Metals 3.3.3.4 MS 33586

Solder and solder flux 3.3.3.5 QQ-S-571 or MIL-F-14256

Wire:Insulated wire 3.3.8.1 MIL-W-76, MIL-W-16878, or


MIL-W-81381

Wire supports 3.3.8.2 Hlah Voltage Cable Assembly


Cr erla Document, Appendix A

Fastener 3.3.10 MIL-F-5591

7.,
S.. ,'7•• •',;• •":•'," ,".",,•-"-'," - ' , • , t ,". ."',- , ,"." "•" " -- ••• ,"•" .•

S 332
4.4.1 Test frequency. When an ac power source frequency is specified
herein, the frequency shall be within +2 percent of the nominal value. The test
frequency shall be the geometric mean of the specified frequency range or a lower
value selected by the manufacturer.

4.4.2 Test voltage. When the rated input voltages are specified with a
tolerance (see 3.1), the test voltage shall be rated voltage (e.g., 5,000 + 100
volts shall be tested at 5,000 v.,'ts). For dielectric withstanding voltage
tests, the peak of the voltage applied shall not exceed by more than 160 percent
the peak of the pure sine voltage.

4.5 Qualification inspection. Qualification inspection shall be performed


at a laboratory acceptable to the Government (see 6.3) on a sample unit produced
with equipment and procedures normally used in production.

4.5.1 Sample size. A sample of one unit shall be comprised of a power


source and shall be submitted for inspection.

4.5.2 Insp:ection routine. The sample unit shall be subjected to the


inspections specified in Table G2 in the order shown.

4.5.3 Failure. One or more failures of the specified qualification inspec-


tion tests listed in Table G2 shall be cause for refusal to grant qualification
aproval.

4.5.4 Test reports. Samples shall be accompanied with certified test


reports in accordance with MIL-STD-831, including a statement that the samples
have been subjected to the tests and comply with this specification. Photographs
of oscilloscope or instrument displays of ripple voltage shall be submitted (see
4.8.2.1). Samples shall also be accompanied with two copies of outline and
detail assembly drawings thereof and two copies of sample instructions with
illustrations and diagrams, if necessary, covering the installation of the power
source.

333
Table G2. Qualification Inspection

REQUI REMENT METHOD


EXAMINATION OR TEST PARAGRAPH PARAGRAPH

Visual and mechanical examination 3.1, 3.3.1.3, 3.3.1.4,


3.3.3.6, 3.3.3.7, 3.4.3,
3.4.3.15, 3.4.3.18.1,
3.4.3.18.2, 3.4.3.19,
3.4.3.19.1, 3.4.3.19.2,
3.4.3.20, 3.4.3.22,
3.4.4.3, 3.7.1 through
3.7.7.,*3.8.1 through
3.8.4, 3.8.7, 3.8.10 and
3.11 through 3.16
Gas filled units 3.3.2.6.1 4.12.1.2
Pressure vacuum transducer 3.3.2.6.2 4.12.2
Liquid temperature transducer 3.3.2.6.3 4.12.2
Pressure-vacuum bleeder 3.3.2.6.4 4.12.2.2
Tanks 7 3.2.6.5 4.12.3
Fans, pumps, and control 3.3.2.6.6 4.12.2.3
ALTERNATING CURRENT GENERATOR

Speed range 3.4.3.1 4.9.2


Load 3.4.3.2 4.9.1
Continuous load 3.4t3.2.1 4.9.1
Overload 3.4.3.2.2 4.9.3
Short Circuit 3.4.3.2.3 4.9.4
Symimetry of construction 3.4.3.3 4.9.5
Efficiency 3.4.3.4 4.9.5
Useful life 3.4.3.5.1 4.9.6
Transient voltage characteristics 3.4.3.6 4.9.4
Voltage buildup 3.4.3.7 4.9.1
Voltage recovery time 3.4.3.8 4.9.2
Voltage regulation 3.4.3.9 4.9.1,4.9.2

Starting performance 3.4.3.11 4.9.7


Exciter 3.4.3.12 4.9.1,4.9.2

Generator field control and 3.4.3.14.1 4.9.1


indication
Anti-cycling and lockout control 3.4.3.14.2 4.9.8

Power ready control 3.4.3.14.3 4.9.1


Underpeed trip circuit 3.4.3.14,4 4.9.1,4.9.2
Overspeed/underspeed 3,4,3.14.5 4.9.1,4.9.2
Charge pressure switch 3.4.3.14.6 4.12.2
Oil, gas and other coolant filtration 3.4.3.16.1 4.12.2

334
.,.,•,',•',-•w'.w',.•,r,.,•.".w..,,•N.,.....,.................-..,..............."....-..............-.....-..+
-•+.,.•t,.•,o+-,.•+ -
- - - •- -. _o. ... ... ,

Table G2." Qualification Inspection (Cont'd)


REQUIREMENT METHOD
EXAMINATION OR TEST PARAGRAPH PARAGRAPH

Seals 3.4.3.16.2 4.12.1


Reservoir 3.4.3.16.3 4.12.3
Helium 3.4.3.17 4.9.9
Detectors 3.4.3.17.1 4.9.9.1
Voltage regulator 3.4.4.4 4.9.10
Useful life 3.4.4.4.6 4.9.6
MAGNETOHYDRODYNAMIC GENERATOR
Continuous load 3.5.3.1.1 4.10.1
Overload 3.4.3.1.2 4.10.2
Short circuit and open circuit 3.5.3.1.3 4.10.3
Efficiency 3.5.3.2 4.10.4
Useful life 3.5.3.3.1 4.10.5
Voltage requirement 3.5.3.4 4.10.1
Voltage 3.5.3.4.1 4.10.1
Voltage recovery time 3.5.3.4.2 4.10.2
Transient voltage characteristics 3.5,3.4.3 A.iO.2
Starting performance 3.5r.3.5 10.1
Magnet 3.5.3.6 10.6
Seals 3.5.3.6.2 12.1
Exhaust gas 3.5.3.6.3 .10.1
Magnet start and stop 3.5.3.6.4 4.10.6
Shielding 3.5.3.6.5 4.13.5
Retention of magnetism 3.5.3.6.6 4.10.6
Tankage and storage 3.5.3.7 4.12.3
Pressure-vacuum bleeder 3.5.3.7.2 4.12.2.2
Monitor 3.5.3.7.3 4.10.1
Cooling air 3.5.3.8 4.10.1
flHD system control 3.5.4.1.1 4.10.1
Magnetic field protection 3.5.4.1.2 4.10.1
Fault isolation control 3.5.4.1.3 4.10.2
Power ready control 3.5.4.1.4 4.10.1
Cooling 3.5.5 4.10.1
Helium 3.5.6 4.9.9
MHD processing and control unit 3.5.7 4.10.1
Monitor and display unit 3.5.8 4.10.1
Exhaust gases 3.5.9 4.10.1

ENVIRONMENTAL TESTS

Tempereture and altitude 3.6.1 4.11.1,4.11.2


Humidity 3.6.2 4.11.3
Sand and dust 3.6.3 4.11.4
Salt spray 3.6.4 4.11.5

335

ýx. 211
Table G2. Qualification Inspection (Cont'd)

REQUIREMENT METHOD
EXAMINATION PARAGRAFH PARAGRAPH

Fungus 3.6.5 4.11.6


3.6.6 4.11.7
Shock
Vibration airplane 3.6.7.1 4.11.8
generator 3.6.7.2 4.11.8.3
Flammability 3.6.8 4.11.9
Nuclear radiation 3.6.9 4.11.10

ELECTRICAL

Bushings 3.8.3.4 4.12.6


Solderabililty 3.8.5 4.12.7
Resistance to soldering heat 3.8.6 4.12.8

GroundinS 3.8.8 1.12.9


3.8.9 4.12.10
Surge arrestors

HIGH VOLTAGE

3.9.1 4.13.1
Insulation resist~nce
3.9.2 4.13.2
Dielectric withstanding voltage
3.9.3 4.13.3
Partial discharges
3.9.4 4.13.4
Pulse
3.9.5 4.13.5
Electromagnetic compatibility

en7

336
.8 *,'•,..,* ,- -, •. ....-. ,.'..,, '.. . .*,. .-..-.-.-- ,..--- -. ,.-.... ~.
...-. . -.. ,,.-.***''a.h.-... 4". . , , ,
.1

r ' ~.
*4.5.5 Rejection and retest of qualification and quality conformance units -

Units which have been rejected or returned to the manufacturer for any reason
during qualification or quality conformance tests may be reworked or have parts
replaced to correct defects. Before resubmitting the unit, full particulars
concerning the reJection and corrective action taken by the manufacturer must
be submitted in writing by the manufacturer to the tezt activity and to the
procuring activity. Tests shall not be resumed until such a report is received.
Where qualification tests are conducted under the auspices of the manufacturer,
the procuring activity shall be advised upon failure of a qualification sample
and of the action taken by the manufacturer with regard to the failure.

4.5.6 Retention of qualification - To retain qualification, the supplier


shall meet the requirements of 4.5.2 every 36 months. The qualifying activity
shall be notified in advance before action is initiated for retention of
qualification. The supplier shall also forward at 12-month intervals to the
qualifyng activity a summary of the results of the tests performed for
inspection of product for delivery, groups A and B, indicating as a minimum
the number of lots that have passed and the number that failed. The results
of tests of all rework lots shall be identified and accounted for. Group A
products shiall be for alternating current generators; group B products shall be
for MHD generators.

4.6 Quality conformance inspection

4.6.1 Inspection of product for delivery - Inspection of the product for


delivery shall consist of the inspections and tests specified in Table G3.

All deliverable high voltage, high power - power sources shall be subjected
to the inspections specified in Table G3.

337

- '. - * *.-: -. ...... .. *. *... ..-.-.. ° ...- **.. .... -....... .....
. .........
q.

Table G3. Quality Conformance Inspection

REQUI REMENT METHOD


EXAMINATION OR TEST PARAGRAPH PARAGRAPH
Visual and mechanical examination 3.1, 3.3.2.6.1 through
3.3.2.6.6, 3.4.3.15
through 3.4.3.21,
3.4.4.2 through
3.4.4.4.6, 3.5.3.6
through 3.5.7, 3.5.9,
3.7 through 3.7.7, 3.8
through 3.8.10, 3.11
through 3.17

ALTERNATING CURRENT GENERATOR

Load 3.4.3.2 4.9.1


Short circuit and open circuit 3.4.3.2.3 4.9.4
Efficiency 3.4.3.4 4.9.5
Voltage 3.4,3.7 4.9.1
Seals 3.4.3.16.2 4.12.1
Helium 3.4.3.17 4.9.9
MAGNETOHYDRODYNAMIC GENERATOR
Continuous load 3.5.3.1.1 4.10.1
Short circuit 3.5.3.1.3 4.10.3
Efficiency 3.5.3.2 4.10.4
Vo!',l, 4. buildup 3.5.3.4.1 4.10.1
Seals 3.5.3.6.2 4.12.1
Monitor and display unit 3.5.7 4.10.1

HIGH VOLTAGE TESTS

Inslation resistance 3.9.1 4.13.1


Dialectric withstanding voltage 3.9.2 4.13.2
Partial discharges 3.9.3 4.13.3
Electromagnetic compatibility 3.9.5 4.13.5

338

•-'•••%
•; •%-• .-. • ..... ,.*. * -: " .,,.. ,.. " . ..... , -- -, . ... " .. ,
4.6.1.1 Insoection lot - Inspection shall be for a completely assembled power
source of the same family, type, and class having similar electrical character-
istics, manufactured under essentially the same conditions, and having similar
construction and mat-rials. (Similar construction and materials shall be
construed to include differences that will not affect test results.)

4.6.1.2 Rejected lots - If an inspection article is rejected, the supplier


may rework it to correct the defects, or screen out the defective components
and resubmit for reinspection. Resubmitted lots shall be inspected using
tightened inspection. Such articles shall be separate from new articles and
shall be clearly identified as reinspected articles.

4.6.1.3 Disposition of units - Units which have passed inspection may be


delivered on the contract or purchase order,only if the units are accepted and
are still within specified electrical tolerances, and if the terminals of
the sample units are clean and smooth.

4.6.2 Inspection of preparation for delivery- The inspection of the


preservation-packaging and interior package marking F1:1i be in accordance
with the quality conformance inspection requirements of MIL-P-116. The
inspection of the packing and marking for shipment and storage shall be in
accordance with the quality assurance provisions of the applicable container
specification and the marking requirements of MIL-STD-129.

4.7 Methods of examination and test

4.7.1 Visual and mechanical examination - Visual and mechanical exaw.,nations


shall apply to group A and group B power sources.

4.7.1.1 External - The power source shall be examin, to verify that the
materials, external design and construction, physical dimensions, weight,
marking, and workmanship are in accordance with the applicable requirements
(see 3.1, 3.2, 3.3, 3.4.3.22, 3.5.3, 3.7 through 3.7.7, 3.8 through 3.8.10,
3.1., 3.15 and 3.16).

339
"-" '-•"•""
" "°"'"
" "' "-•"' " """*""" "*"." "" '" ."' .",""" "-"*" "* """ " " *." .' . *.. " . • .•i * . ... _: " -...
4.7.1.2 Internal - The internal parts of the power source shall be examined
"to verify that the materials, internal design and construction, physical
dimensions, marking, and workmanship are in accordance with the applicable
requirements (see 3.1, 3.3.2 through 3.3.8.2, 3.3.10 through 3.3.10.3,
3.4.3.14 through 3.4.3.22, 3.5.3.6.2, 3.5.3.7, 3.5.4 through 3.5.8, 3.7, 3.8
through 3.8.7, 3.8.9, 3.8.10, 3.14, 3.15 and 3.16). Internal design,
construction, and workmanship will include inspection for:

a. Dirt and debris.


b. Loose ends on wire bundling lacing and ties.
c. Rough surfaces on corona shields.
d. Correct spacing of high voltage wiring.
e. Burns, scratches, foreign deposits, and delamination of insulating boards.
f. Grease, oil, or water leaks.
g. Seals
h. Cooling-ducts and tubing
i. Cryogenic line and auxiliary coupling mechanisms
j. Overboard venting apparatus
k. Sensors and monitor connections and installation

4.7.1.3 Post-test - Power sources shall be examined to verify that the pro-
tective coating, filling material, and case construction are in accordance with
the applicable requirements (see 4.3).

4.8 Electrical performance test conditions

4.8.1 Altitude and temperature - The steady state output characteristics tests
shall be conducted at an ambient temperature of 200C + 100C and an ambient
altitude of-1000 feet to +5000 feet.

4.8.2 Instrumentation - All instruments used to measure time, voltage, and


current shall have an accuracy of 1 percent or less. Instruments shall have
been calibrated within 30 days of the date on which the tests described in
paragraphs 4.8 are conducted unless the instrument history records provide

340
-''''-''-'";"'. : .. '' .:- -" ". .- : - . A*.. .. . - .
sufficient evidence to support longer periods between calibration. All meter
indications shall be equal to or within the tolerance range specified within
this drawing.

4.8.3 Electrical measurements - Steady state electrical measurements of volts,


amperes, ohms, and watts shall be made with laboratory type instruments having
an accuracy of 0.75 percent of full scale.

All photographs of oscilloscope traces shall show the sweep time, vertical
defl--ction sensitivity, rise time of the scope, and amplifier, where applic-
able, and frequency response at the 3 db point.

All oscillograph recordings shall show a calibration trace, and the calculated
values of instantaneous voltage, current, and power from the recordings shall
be accurate to +5 percent. The frequency response of all recording instru-
ments and oscillographs uset! in the tests shall be included in the test data.

*-: •Measurements of frequency shall have an accuracy of +1 Hz.

4.8.4 Temperature measurements - The accuracy of the temperature measurements


shall be +20C.

4.9 Alternating current generator electrical performance - The ability of the


unit to deliver rated power at rated speed for a period of 5 minutes shall be
demonstrated. The generator shall be properly mounted to a prime mover
qualified to bring the generator from standstill to full speed and full load
in the period as defined in the detailed specification. The prime mover and
generator shall be subjected to the electrical, mechanical and environmental
":3 tests required by the specification and listed in table G2.

4.9.1 Continuous load - The power source assembly shall be started,-brought


to full 1.0 + 0.05 P.U. rpm and 1.0 P.U. MW and operated for five minutes.
During this test the following parameters shall be monitored:

.* . . . C . C C* . - .* C. .
C -- C

341
a. Coolant inlet and outlet temperature
b. Room ambient air temperature
c. Cryogenic helium consumption
d. Cryogenic temperature ýincludes cooling time)
e. Machine critical hot-spot temperature
f. Phase-to-neutral and line-to-line voltages and currents
g. Power output
h. Fuel consumption
i. Exciter output voltage and current
j. Control relay operation
k. Sensor inputs to the monitor
1. Display
m. Helium gas ducting system
n. Heliumleakage

Time to cool cryogenic components to operating temperature shall be recorded.


Quantity of helium used shall be measured and recorded. During the start up
and stopping period, the operation of the power ready control, underspeed/
overspeed protection, generator field control, and frequency controls shall be.
monitored for proper function. The generator field control shall be monitored
by monitoring generator output modulation.

4.9.2 Speed range - The generator shall be brought up to speed and stabilized
at 1.0 + 0.05 PU rpm for 10 seconds minimum with 1.0 + 0.05 PU MW output from
the qenerator. The prime mover speed control shall be adjusted to operate from
1.0 + 0.05 PU rpm to 1.15 + 0.05 PU rpm to 0.9 + 0.05 PU rpm to 1.0 + 0.05 PU rpm
in 2 minutes time. The exciter and control system shall hold the output at
1.0 + 0.05 MW during this test. The overspeadfunderspeed frequency control relays,
shall be adjusted to accept this speed range without.shutting off the prime mover
or generator output.

4.9.3 Overload - The power source assembly shall be brought to 1.0 + 0.05 PU
rpm and 1.0 + 0.05 PU MW. After 10 seconds minimum, the load shall be changed to
accept 1.25 PU MW load for 10 seconds and 1.5 PU MW load for 1 second at

342
.. ,•.-o...°.oo......•.o ... o o. .. ...... . o .. . .. . .
•- • °. • ° - ,•° . °.° • , • % . % •° , , . ° '% ° . °o. o° °• , ° ° °. o . -
which time the unit load shall be reduced to full load for 10 seconds and
turned off. Measured parameters shall include:

a. An oscillcgraph or a magnetic tape reproduction of the monitor olitput of


generator voltage, current, speed, power voltage modulation. Likewise
recordings of the exciter and control system shall be made.

b. Parameters a through n of paragraph 4.9.1 shall be recorded.

4.9.4 Short circuit - the power source assembly shall be brought to 1.0 +
0.05 PU rpm and 1.0 + 0.05 PU MW output and stabilized at full
load for 10 seconds. A short circuit shall be applied to the output. The
fault isolation control shall operate to limit the fault current to less than
1.5 PU MW and the control unit shall ramp the exciter toward zero output. No
damage or overstress shall be caused by this test. Measured parameters shall
include items a through n of paragraph 4.9.1. Permanent recordings of the
generator, exciter and fault isolation control relay shall be made during
this test. Phase output voltages shall be within + 0.2 PU volts of nominal
output voltage during the fault.

4.9.5 Efficiency and symmetry of construction - The system electrical


efficiency and the generator symmetry of construction shall be calculated
from the data of paragraph 4.9.1.

4.9.6 Useful life - Useful life shall be verified by test. The qualification
model shall be operated at 1.0 + 0.05 PU MW at 1.0 + 0.05 PU rpm for 2.5
minutes per hour for 30 days for a total of 30 hours operation. During
this testcontrol adjustments and resupply of fuel and coolants are
permitted.

Each machine built to the same specification and drawings as the qualification
model shall be tested for 10 cycles of 2.5 minutes per hour at full load and
normal operating speed; i.e., 1.0 + 0.05 PU MW and 1.0 + 0.05 PU rpm.

4
4
343
•.•.•..'.'.."y.'• . .-....... ,..'......- ..-.. ........ . .......
. .-.. .-.,-.•.......
.... -.. -..... • .... . ..
• " ." . ; . " -" ' ,. .' '..,' ',. -. .- ..' - ,' '. - ,',-.'.
', - - -. , " ,., .- .. -" -" ." -"- -" .- " -- - -"-,-' ' -" °. " '--. ', , '
4.9.7 Temperature (see 3.4.3.12) - The test of paragraph 4.11.1 shall apply.
Temperature shall be stabilized to the extent that all required heaters and
non-heated parts are thermally stabilized internally and externally. The
test shall be complete after the machine has successfully passed 10 cycles
"of 2.5 minutes per hour in one 24 hour period. This test may be considered
part of the useful life test of paragraph 4.9.6.

4.9.8 Anticycling control - The control system shall be operated in a manner


to simulate faults (power outages) of the airplane power system, the
emergency power system, and the generator output. The anticycling and lockout
control relay shall operate to properly keep continuous power to the other
control relays.

4.9.9 Helium - Helium shall be of technical grade as defined in Federal


Specification BB-H-1168. Dewar, lines, and filters shall be free of lint,
dirt and foreign materials such as water and gases. Tanks and equipment
shall be evacuated as specified in 4.12.3.2.

4.9.9.1 Helium detector - Helium detectors installed in the power supply


assembly and the assembly area shall be tested at least three times during
qualification. No damage to the equipment or sensor shall result from these
tests.

4.9.10 Voltage regulator - The voltage regulator shall be tested as part of


"the power source assembly. The exciter shall meet all the requirements of
paragraph 4.9.1 through 4.9.7.

4.10 Magnetohydrodynamic generator electrical performance - The ability of the


unit to deliver rated power for 5 minutes shall be demonstrated. The generator
shall be properly mounted on a test platform with all ancillary equipment
attached, including regulator coolant loops, fuel and coolant supplies,
monitor and control, displays and test instrumentation.

344

• . "°o . -. ". • • .
w - .'• - • . ,• °• .. .• ° . - . - . •
4.10.1 Load - The MHD generator assembly shall be started, brought to full

j '..: load 1.0 + 0.05 PU MW1 in one second, ane operated for five minutes. The
following parameters shall be measured and monitored during the test:

a. Room ambient air temperature


b. Coolant irilet and outlet temperature
c. Cryogenic helium consumption
d. Helium temperature inlet and exhaust
e. MHD channel temperatures
. Fuel consumption - fuel and seed
g. Helium gas ducting system
h. Helium leak detector
i. Exhaust temperature
j. Exhaust signature
k. Power output
1. Voltage
n. Control relay operation
n. Sensor operation to the processor and monitor subassemblies
o. Display
p. Monitor

Time and quantity of helium to cool the cryogenic subassemblies shall be recorded.
The operation of all control relays shall be observed and monitored for proper
function during the test.

After five minutes operation the MHD generator shall be shut down. Oscillograph
or magnetic tape repruduction of the monitor inputs and outputs shall be
obtained during start and stop. Included shall be voltage, current, power, and
voltage modulation for the 5 minute run.

4.10.2 Overload - The MHD generator assembly shall be brought up to full power
output in one second. The measurements and load applications of paragraph 4.9.3
shall apply.

345

42,•
. • 7 "•2 - "'. " . - • , ' • -" . " -"• .." . - -"-
." a-" - ". ." ~.
". . "• " . . " . . ." . " . " ."' . . " - -" . "-. a" -.
-. Z .77

4.10.3 Short circuit - The MHK generator assembly shall be brought up to


1.0 ±0.05 PU MW in one second and stabilized for 10 seconds. A short circuit
shall be applied to the output terminals. The fault isolation control shall
operate and shut down the generator by limiting the current to less than 1.5
PU amperes. No damage or overstress shall be caused by the short circuit to
any subassembly or part. Measured parameters shall include items a through p
of 4.10.1. Oscillograph and/or magnetic tape reproduction of the start through
complete stopping of the equipment shall be made during the test.

4.10.4 Efficiency - MHiD generator assembly efficiency shall be calculated


from the data obtained during the load test, 4.10.1.

4.10.5 Useful life - Useful life shall be verified by test. The qualification
assembly shall be subjected to 2.5 minutes per hour at full load (1.0 ±0.05 PU
MW) for 30 days t24 hours per day). During this test, control adjustment and
resupply of coolants and fuels is permitted. Parts and subassembly changes are
cause for failure.

Each production model built to the same specification and drawings or the
qualificatiorn model shall be tested for 20 hours at 2.5 minutes per hour, at
full load, as an acceptance test.

4.10.6 Magnet - The magnet, magnet control circuit, and helium coolant subsystem
for the MHD generator assembly shall meet the performance rcquiremenVt of
paragraphs 3.5.3.1 through 3.5.3.5. The magnet shield shall be sufficient for
the MHD generator assembly to meet the performance of 4.13.5.

The magnet inputs and outputs shall be detennined at the beginning and end of
the life test. No perceptible degradation of magnetic properties shall be noted.

346

- - - -.. -~ -
4.11 Environmental tests

4.11.1 Thei'mal shock (see 3.4.3.1) - The test article shall be tested in
accordance with method 107 of MIL-STD-202. The temperature for step 3 shall
be the maximum operating temperature for the class. lhe following details
and exceptions shall apply:

a. Test condition - A, 20 hours, for qualification

b. After cycling - The test article shall be examined for evidence of


leakage and other visible damage.

4.' .2 Altitude - Altitude tests are not required for hermetically sealed
pressurized subassemblies. Parts such as cables and connectors on sealed or
pressurized units, and unpressurized, unsealed units which are designed for
operation above 10,000 feet altitude shall be tested in accordance with
method 105 of MIL-STD-202. The test articles shall operate at normal voltage
at the altitude specified in the detailed specification. The power supply
* assembly will not be tested in an altitude chamber. All subassemblies with
open cases (unpressurized) with operating voltages greater than 150 volts,
peak shall be altitude tested.

4.11.3 Humidity - The unit shall be subjected to the humidity test, Method
103B, of Specification MIL-STD-202. Immediately following this test the unit
shall pass the full load test of either 4.9.1 or 4.10.1 as applicable at
nominal input conditions and ambient temperature.

4.11.4 Sand and dust - This týst is not applicable for hermetically sealed
or pressurized subassemblies. Unpressurized or unsealed units shall be tested
in accordance with method 11OA, or MIL-STD-202. The test articles shall be
non-operating during the test.

4.11.5 Salt spray (corrosion). When specified .(see 3.2) - The test article
shall be tested in accordance witri method 101 of MIL-STD-202.

347
.......... . . . .. ,, ... .. .. ............... . •.... ............
!,.
a. Test condition - B.

b. Salt solution concentration - 5 percent.

c. Examination after exposure - The test article shall be thoroughly washed.


The temperature shall not exceed 38°C. The test article shall be placed
in an oven maintained at 500C + 30 C for a period of 24 + 4 hours. At the
end of this period, the test article shall be removed from the oven and
examined for corrosion.

4.11.6 F.'jgus - Unless certification is provided, the test article shall be


tested in accordance with method 508 of MIL-STD-810 (see 3.2).

4.11.7 Shock - The test article shall be tested in accordance with 4.11.7.1,
or when specified (see 3.2), in accordance with 4.11.7.2.

4.11.7.1 Specified pulse - The test article shall be tested in accordance


with method 213 of MIL-STD-202. The following details and exceptions shall
apply:

a. Test condition - I, unless otherwise specified.

b. Examinations after shock - The test article shall be examined for evi-
dence of leakage and physical damage.

4.11.7.2 High-impact - The test article shall be tested in accordance with


method 207 of MIL-STD-202. The following detail and exception shall apply:

a. Mounting fixtures - Figure "Standard mounting fixtures for electrical


controller parts" of method 207.

b. Examinations after shock - As specified in 4.11.7.1(b).

4.11.8 Vibration - The test article shall be tested in accordance with


4.11.8.1 or 4.11.8.2, as applicable.

3483

348
- 4.11.8.1 Vibration, low frequency - The test article shall be tested in
accordance with method 201 of MIL-STD-202. The following details and
exceptions shall apply:

a. Test and measurements prior to vibrating - Not applicable.

b. Method of mounting - The test article shall be rigidly mounted by its


normal mounting means.

c. Procedure - When specified (see 3.2) the test article shall be placed
in a test chamber and preheated to the specified maximum ambient
temperature for the class (see 3.2) plus one-half the allowable
temperature rise. Vibration in each plane shall begin 5 minutes after
removal from the test chamber.

d. Apparatus - The sequence of vibration shall be as follows: First


vertically, and then hori:ontally in two mutually perpendicular direc-
tions. Two machines may be used (one vibrating horizontally and one
vibrating vertically), or a single machine may be used which provides
for both vertici" and horizontal table motion, or a vertical vibrating
machine, at the option of the supplier.

"e. Examinations after vibration - The test article shall be examined for
evidence of leakage and physical damage.

4.11.8.2 Vibration, high frequency (when specified -see 3.2)- The test article
shall be tested in accordance with method 204 of MIL-STD-202. The following details
and exception shall apply:

a. Mounting of specimens - As specified in 4.11.8.1(b).

b. Test-condition - D, unless otherwise specified.

c. Airplane vibration magnitudes defined in the detailed specification


4'. •shall apply (see 3.2).
t'4

341
•L .Q %V'.. .. 4 . . *,,.*,,
. .
... .;.'• ......
• •,:,-. .-. .* -a' ."".".".."....
-g '. , "" ., . •. , . ."". .... . "-......
. ."."""""
".' .....
".".. "".. "
d. Examinations after vibration - As specified in 4.11.8.1(e).

4.11.8.3 Assembly vibration - The test assembly shall not exceed the vibration
limits defined in the detailed specification, when operated at full load for
five minutes.

4,11.9 Flammability (grade 5) - The test article shall be tested in accord-


ance with method 111 of MIL-STD-202. The following details and exception
shall apply:

a. Point of impingement of applied flame - One of the lower free corners,


so that the flame is just in contact with the test article. The free
corners of the '":st article are those corners which are the greatest
distance from the mounting brackets. However, the flame shall be applied
so that it will impinge upon the corner or area containing the encapsulat-
ing compound.

b. Allowable time for burning of visible flame on specimen - 3 minutes


maximum.

c. Examinations during and after test - The test article shall be examined
for evidence of violent burning which results in an explosive-type fire,
dripping of flaming material, and visible burning which continues beyond
the allowdble duration after removal of the applied flame.

4.1.10 Nuclear radiation - When specified by the detail specification, a

nuclear radiation exposure test shall be conducted in accordance with


Standard MIL-ST.-446. When required, the unit shall pass the full load test
of 4.8.2 after completion of the radiation exposure.

350

* *..*. ~z
4.12 Mechanical and electrical tests

4.12.1 Sea! - The test article shall be tested in accordance with 4.12.1.1,
4.12.1.2, or 4.12.1.3, as applicable. Any unit or subassembly which shows
evidence of leakage may be given remedial treatment. After completion of
the treatment, the seal test shall be repeated as evidence that such remedial
treatment is adequate. All other units in the lot which have been given similar
satisfactory remedial treatment shall be acceptable.

4.12.1.1 Liquid-filled units - The test article shall be heated in an oven


maintained at a temperature equal to or not more than 50 C greater than the
sum of the specified maximum ambient temperature and the allowable tempera-
ture rise (see 3.2), for not less than 6 hours.

4.12.1.2 Gas-filled units - The test article shall be tested in accordance


with me'thod 112 of MIL-STD-202. The following details shall apply:

a. Te.st condition - C.

b. Leakage-rate sensitivity - 10-3 Pascal-cubic centimeter/second.

c. Procedure IV, as specified (see 3.1 and 6.1.2), test for gross leaks
as specified in 4.12.2.

351

* .R.. . **.
4.12.2 Auxiliary components - Auxiliary components include pressure and tem-
perature transducers and switches, fans, pumps, and controls. These units
shall be tested at least three times during qualification. No damage to the
test assembly or device shall result from these tests.

4.12.2.1 Transducers - Pressure-vacuum transducer and liquid temperature


transducers shall be tested at least three times during qualification. No
damage to the test assembly or sensor shall result from these tests.

4.12.2.2 Pressure vacuum bleeder - The pressure vacuum bleeder valve shall
be tested at least three times during qualification. No damage to the test
assembly or sensors shall result from these tests.

4.12.2.3 Motors - Fan, pump, and control motors shall be tested for electrical
continuity. Fan and pump motors shall function, without failure, during the
life test.

4.12.3 Tank design proof pressure - Proof pressure cycle tests shall be con-
ducted in accordance with MIL-STD-1540. The temperature of the test shall be
stabilized and maintained at a temperature of 71 0 C throughout the test.

As an alternative, the test may be conducted at room temperature if the test


pressure is suitably adjusted to account for temperature effects on strength
and fracture toughness.

Proof pressure cycles shall consist of raisiwr the tank piping, fittings or
hose internal pressure to 1.5 times the maximum operating pressure specified
in the detai'led specification, maintaining this pressurc for 5 minutes and
then decreasing the pressure to 0 psig. There shall be no evidence of leakage
during the test.

The following test cycle shall be performed:


Test Cycle
Acceptance 1
Qualification 3

"352

. o .'.S . , - -. .o.-. o o - .~ .-o . -- . . -- -- 5. , °. . . • . .


" .- At the conclusion of the test there shall be no evidence of yielding of the
tank mat,.rial. The volumetric change shall be determined and recorded.
Permanent volumetric change shall not exceed 0.2%.

4.12.3.1 Tank design, burst - Design burst pressure test shall be conducted
i - in accordance with MIL-STD-1540. The temperature of the test shall be
stabilized and maintaineo at a temperature of 710 C throughout the test.
--.9
,.

As an alternative, the test may be conducted at room temDerature if the pres-


sure is suitably adjusted to account for temperature effects on strength and
fracture toughness.

Burst pressure tests shall consist of raising the tank pressure to 4 times
the maximum operating pressure specified in the detailed specification and
maintaining this pressure to verify that the design burst pressure is met or
exceeded. The internal pressure shall be applied at a uniform rate such that
stresses are not imposed due to shock loading.

4.12.3.2 Internal vacuum - The tank shall be evacuated to an absolute


pressure of 100 pascals, maximum, internal pressure for 15-minutes duration
"while exposed to ambient pressure externally. No permanent deforration shall
be sustained.

4.12.4 Cooling - This test shall be performed during the steady state confo,-
mance operating time tests of paragraph 4.9.1 or 4.10 as applicable. The test
shall be performed with coolant temperatures and equipment temperatures stabi-
lized at ambient temperature of 23 + 5°C. During the test, coolant inlet and
outlet temperatures shall be recorded for test and standby conditions. Coolant
system efficiency shall be determinret for each stage of the test. Data on heat
rejection (defined as the differenca between input and output power expressed
in kilowatts) shall be furnished for the above tests. The power source shall
conform to the specified requirements of paragraph 3.4.3.16 or 3.5.5.

353
The coolant system shall be tested in accordance with paragraphs 4.12.3 and
* 4.12.3.1. There shall be no evidence of leakage during the test.

4.12.5 Terminal strength - The article subassemblies shall be tested as


, specified in 4.12.5.1 through 4.12.5.2.2 inclusive, as applicable. After
each test, the te'-ninals shall be examined for loosening arid rupturing and
other mechanical damage. Unless otherwise specified, all terminals on each
test sample shall be subjected to the following tests, up to a maximum of
four identical terminals per sample.

4.12.5.1 Pull

4.12.5.1.1 Solid-wire and insulated wire lead terminals - The test article
subassemblies and auxiliary components, such as sensors and motors, shall be
tested in accordance with Method 211 of MIL-STD-202. The following details
shall apply:
a. Test condition - A.
b. Points of measurement - A force shall be applied in the airection of the
axis of termination and shall be inrreased gradually until the magnitude
specified in table IV is reached and shall be maintained for a period
of 5 to 10 seconds.

4.12.5.1.2 Solder terminals - Auxiliary components shall be tested in accor-


dance with Method 211 of MIL-STD-202. The followi:. details shall apply:
a. Test condition - A.
b. Points of measirement - A force as specified in table G4 shall be applied
to each terminal at the point where the lead front the external circuit
connects to it. The force shall be applied in the weakest direction of
the terminal and shall be increased gradually to the specified magnitude
and shall be maintained at that value for a period of 5 to 10 seconds.

354
. *~O°o°* . *,* - * .*. * . . ' . * .
"C:- :::~:TABLE G4. Pull.

Cross-sectional area of electrode at its


smallest point at which lead from Force
external circuit connects

Circular mIls Pounds

S 2,000 ------------------------------ 2.0


> 2,000 ------------------------------ 5.0

"4.12.5.2 Twist or bend

4.12.5.2.1 Sclid-wire lead terminals (other than printed circuit terminals) -


Following the test specified in 4.12.5.1.1, the article subassembly terminals
.* shall be tested in accordance with Method 211 of MIL-STD-202. The following
detail and exception shall apply:
a. Test condition - D.
b. Application of torsion - The body of the component part or the clamped
terminal shall be rotated through 360 degrees about the original axis
of the bent terminal, in alternating directions, for a total of five
rotations, at the rate of approximately 3 seconds per rotation.

4.12.5.2.2 Flat solder terminals - Any terminal that shows permanent deforma-
tion greater than 15 degrees of the metal portioq of the terminal in the
terminal-pull test specified in 4.12.5.1.2 shall be tested in accordance with
Method 211 of MIL-STD-202. This test does not apply to terminals which show
permanent deformation but are not designed to be bent 45 degrees. The
following detail and exception shall apply:
a. Test condition - B.
b. Number of bending operations - Five times through an argle of 90 degrees
(45 degrees each side of center).

355
"" 4.12.6 BushingsThe basic insulation level
- (pulse test) of bushlings
shall be twice rated voltage. Bushings shall be given dielectric withstanding
voltage tests of 1.6 times rated voltage.

4.12.7 Solderability
Solder connections for the power source shall be
-

tested in accordance with 4.12.7.1 or 4.12.7.2, as applicable. The method in


4.12.7.1 is preferred and shall be specified whenever practicable, otherwise
the method in 4.12.7.2 shall be used.

4.12.7.1 Solder bath method - Solder connections shall be tested in accor-


dance with Method 208 of MIL-STD-202. The following details shall apply:

a. Special preparation of specimen-Sample components shall not have been


soldered during any of the previous tests.
b. Number of terminations of each part to be tested - A minimum of two of
each type of terminal.

4.12.7.2 Soldering iron method - The test shal l be performed on solder


terminations, attached to the power source parts. The solder shall conform
to type S, composition Sn60, of QQ-S-571. The flux shall conform to type A or
W, as applicable, of MIL-F-14256. The temperature of the bit shall be 300" -
350*C. The iron and solder shall be applied to the termination for 10 seconds.
The solder shall be applied for the first 2 secoads. Tinning, as evidenced by
the free flowing of the s3lder with proper wetting of the U.rmination, shall
be completed within the fi, o two seconds. The part under test shall remain
under standard atmospheric conditions for recovery for fifteen minutes, before
final measurements are made.

a. Special preparation of specimen - The surface shall be smooth and


properly tinned and the solder terminations shall not have been soldered
during any preiious test.
b. Number of terminations - in accordance with 4.12.7.1.
c. Examinations of terminations - in accordance with Method 208 of
MIL-STD-202.

356
-.-. -,..,-.. ,•, .. --......... '...
•. 4 IL•-m. < --. . •• -•-
• •,: • -• ° S....•. -;, .4 .• -t• • - ° .- ---- ;---r'
. -•- L . -. • • .°°.

.V7

d. Soldering irons - The soldering iron shall have one of the following
bit sizes:
(1) 0.3 inch diameter, 1.25 inch exposed length reduced to a wedge
shape, over a length of approximately 0.4 inch.
(2) 0.125 inch diameter, 0.5 inch exposed length, reduced to a wedge
shape. over a length of approximately 0.2 inch.
e. Point of application of soldering iron - 1/4 inch from the nearest
insulating material or to one-half the exposed length of the terminal,
whichever point is closer to the insulating material. -

4.12.8 Resistance to soldering heat - Power source parts shall be tested in


accordance with 4.12.8.1 or 4.12.8.2, as applicable. The method in 4.12.8.1
is preferred and specified whenever practical, otherwise the method in 4.12.8.2
shall be used. These tests.shall apply to conductors and magnetic devices only.

4.12.8.1 Solder bath method - Power source parts shall be tested in accordance
with Method 210 of MIL-STD-202. The following details shall apply:
a. Special preparation of specimen - Sample units shall not have been
soldered durinag any of the previous tests.
b. Depth of immersion in the molten solder - To a point 1/4 inch from the
nearest insulating material or to one-half the exposed length of the
terminal, whichever point is closer to the insulating material.
c. Test condition - A (350 + 1OC; +0 seconds).
-- in~nersion, 3 --
d. Examination after test - The parts shall be viF ily examined and there
shall be no seepage of the impregnant, loosenir,q of the terminals, or

other mechanical damage. The parts shall be checked for continuity.

4.12.8.2 Soldering iron method - The test shal' be performed on all solder
terminations, attached to the power source parts. The solder shall conform to
type S, cumpositlon of Sn60 of QQ-S-571. The flux shall conform to type A or
W, as applicable, of MIL-F-14256. The temperature of the bit shall be 3000 -
350°C. 1,.e iron and sclder shall be applied to the termination for 10 seconds.

357
I
i4

Fhe solder shall be applied for the first 2 seconds. Tinning, as evidenced by
the free flowing of the solder with proper wetting of the termination, shall
be completed within the first two seconds. The parts under test shall remain
under standard atmospheric conditions for recovery for fifteen minutes, before
final measurements are made.
a. Special preparation of specimen - The surface shall be smooth and properly
tinned and the solder terminations shall not have been soldered during any
previous test.
b. Examinations after test - in accordance with 4.12.8.1.
c. Soldering irons - The soldering iron shall have one of the following bit
sizes:
(1) 0.3 inch diameter, 1.25 inch exposed length reduced to a wedge
shape, over a length of approximately 0.4 inch.
(2) 0.125 inch diameter, 0.5 inch exposed length reduced to a wedge
shape, over a length of approximately 0.2 inch.
d. Point of application of soldering iron - 1/4 inch from the nearest
insulating material or to one-half the exposed length of the terminal,
whichever point is closer to the insulating material.

4.12.9 Grounding and bonding - Resistance measurements shall be conducted on


at least two subassembly grounds, representative of the power source. Visual
inspection shall be conducted in all power source subassembly and assembly
grounds and bonds to the airplane structure. Bonds and grounds between the
power source assembly and subassembly parts shall be in accordance with
MIL-B-5087.

4.12.9.1 Grounding The bonds selected shall be tested with a direct current
-

source. The measured impedance with average transient current passing through
the joint shall be less than 2.5 milliohms, maximum, between the power source
assembly or subassembly and the airplane structure.

4.12.9.2 Lightning and electromagnetic pulse susceptibility test - A tran-


sient generator similar to that shown in Figure G5ashall be used. The voltage
source, capacitor C, and resistor R shall be adjusted to obtain transient "X"
in Figure G5bfor ground potential transient susceptibility test, and "Y" for
interwire induced transient susceptibility test.

358

" """"" " " " ....-" ".. .. . . . . . . ...


. ..
a. Ground potential transient susceptibility test. With the transient
. generator output connected between ground and all the ground leads of
the power source assembly bunched together, and the system operating
under full load conditions, ten positive and ten negative ground
potential tri .-.tents (Figure G5b, transient X) shall be applied suc-
cessively. There shall be no failure of components or impairment of
subsequent performance as a result of the test.

4.12.10 Surge arresters. Surge arrestors shall be disconnected during


pulse testing and dielectric withstanding voltage tests. Surge arrestors shall
be tested by applying pulses in accordance with IEEE Std 28-1974/ANSI C62.1-1975.

359
4.13 H.V. Evaluation tests ,, Power source assemblies and subassemblies with
output voltages greater than 500 volts peak, shall be tested as specified in
the following paragraphs.

* 4.,3.1 Insulation resistance - The power source assembly and subassemblies


shall be tested in accordance with Method 302 of MIL-STD-202. The following
details and exceptions shall apply:

a. Test condition - B for qualification inspection; and dc test potentials


from 500 volts to 10,000 volts for quality conformance inspection.
However, for quality conformance inspection, rejection shall be based
on measurements made at 500 volts.

b. The measurements shall be made at ambient room temperature, humidity,


but rejections shall be based on measurements made at 25°C +100 and at
:-5oc
a relative humidity not greater than 80 percent. Insulation resistance
shall be greater than 100 megohms.

4.13.2 Dielectric withstanding voltage - Power source assemblies and sub-


assemblies shall be tested in accordance with 4.13.2.1 and 4.13.2.2, when
applicable.

4.13.2.1 Atmospheric pressure - Power source subassemblies shall be


tested in accordance with method 301 of MIL-STD-202. The following details
and exceptions shall apply:

a. Magnitude of test voltage shall be 160% of working, voltage.

b. Nature of potential - ac or dc, as applicable.

c. Duration of application of specified test voltage - Minimum of 60 t5


seconds for quality conformance inspection, 1 minute for qualification
inspection.

360
.. S° -.
Sm
%-*'
. • .• . •
*. *-• *.• .\°.•
.• • ' • ' ....
•F..
*.~
.
*- °
.
.' ".
.- .

••
.
°
...
"
°.. .. " .
• •
•.. ...
• • •
•°
•o
o
"••"
. ."

.° ,
°••°. .-. .•,•• "
, d. Points of application of test voltage:

1. Input leads - Between input leads and case or ground. Sensors and
control circuits connected between the input and ground shall be

disconnected.

2. Output and ground - Between output leads and case or ground. Sensors
and control circuits connected to the high voltage output shall be
disconnected;
3. Circuits with direct current rated capacitors shall be tested with
dc of the proper polarity.

4. Neutral lead shall be disconnected during test.

e. Examination during and after test - The assembly and subassemblies shall be
examined for evidence of arcing, flashover, breakdown of insulation, and
damage.

4.13.2.2 Altitude - Power source assemblies and subassemblies designed for


oi .. ation above 10,000 feet shall be tested as specified in 4.13.2.1 dnd in
accordance with method lOb of MIL-STD-202. The following detail and exceptions
shall apply:

a. Test condition or altitude in feet if below 30,000 feet - As specified


(see 3.2).

b. Magnitude of test voltage shall be 160% working voltage, ac or dc, as


applicable, with polarity in accordance with tested parts.

-• c. Examination during and after test - Power source assemblies arid subassemblies
shall be examined for evidence of arcing, flashover, breakdown of insulation,
.t. and damage.

•-3

* .- 361

w '•.%~
*.Z 4 •--' ,% **..'t.b •.- '*_ 4.4'•, q." .• -' ,-'-'.,°' .~- .. " " .. .4" ._'- . .' ." ."•.- " • .. .. 4 ." -
4. 13.2.3 Special applications. High voltage coils and coil assemblies shall be tested
individually to the voltage levels specified in paragraph 4/.13.2.2b.

4.13.2.4€ At reduced voltage. Power source assemblies after qualification shall be


subject to the dhcllectric-wj'.hstanding voltage tests specified in 4•.13.2.1, except that the
test voltages siiall be 125% of the working voltage and shall be applied for a period of 60
seconds.

4.13.3 Partial discharges. When specified (see 3.2), power source subassemblies
shall be tested in accordance with 4.13.3.1 or 4.13.3.2, or 4.13.3.13, as applicable. The
detector used for this test shall have the sensitivity of one picocoulomb or less and shall
have a reasonably uniform response up to 500 kilohertz. Partial discharge peak
magnitudes shall be as defined in the detailed specification for a 3-minute test at rated
voltage.

4.13.3.1 Input circuits. When specified (see 3.2), the generator high voltage
auxiliary equipment input circuits shall be tested for partial discharges. Partial discharge
peak magnitudes shall be less than 13 px:/kV or as defined in the detailed specification,
during a 3-minute test at rated input voltage.

4.13.3.2 Output circuits. When specified, (see 3.2), the high voltage output circuit
shall be tested for partial discharges. Partial discharge peak magnitudes shall !5e less than
500 picocoulombs during a 3-minute test at rated output voltage.

4•.13.3.3 Operational. When specified (see 3.2), the partial discharge dete•ctor shall
be connected to the power source high voltage output circuit and the unit shall be tested
for partial discharges. The partial discharge test shall be started 10 seconds after rated
voltage is stabi~lized. The output voltage shall be at rated voltage. Partial discharges
shall not exceed the following limits

Voltage Limit Counts/iMinute Not to Exceed


KV PC/KV Over Limit Pn'..,j".Y
AC 15 6 30

4.13.4 _Puls_.e. When pulse tests on line terminals are specified (see 3.2), there shall
be no momentary or intermittent arcing or other indication of breakdown or flashover, nor 7
shall there be any visible evidence of damage,

362
Sr•
• . • . 4• . . -• • °• •- • • - • . • - -
4.13.4.1 Connections for pulse tests. In general, the tests shall be applied to each
high voltage terminal, one at a time.

4.13.4.2 Terminals not being tested. Neutral terminals shall be solidly grounded
except in the case of low impedance windings. Line terminals shall be either solidly
grounded or else grounded through a resistor with an ohmic value not in excess of the
following values:

Nominal System
Voltage Resistance
(kV) (Ohms)
345 & below 500
500 400
700 300

4.13.4.3 Wave to be used for pulse tests. A nominal 1.2 x 50 microsecond wave
shall be used for pulse tests.
Positive or negative waves may be used. The polarity shall be in accordance with the
Sr.circuit polarity.

The time to crest shall not exceed 2.5 microseconds, except for circuits having large
capacitance.

4.13.4.4 Voltage. The basic insulation voltage level to which the power source shall be
tested is 200 percent rated peak voltage, or as defined in the detailed specification.

4.13.5 Electromagnetic interference. At no load or minimum load point, as applicable,


half rated load, and rated load, radiated interference, and both the input and output
conducted interference shall be measured using the test procedures and applicable
instruments specified in Specification MIL-STD-462 per the requirements set forth in the
detailed specification and MIL-STD-461.

363
4. '
5. PREPARATION FOR DELIVERY

5.1 Preservation-packaging - Preservation-packaging shall be level A or C, as


.. ,pecified.

5,1.1 Level A

5.1.1.1 Cleaning- Power source assemblies and subassemblies shall be cleaned


in accordance with MIL-P-116, process C-i.

5.1.1.2 Drying- Subassemblies shall be dried in accordance with MIL-P-116.

5.1.1.3 PresermD:itive application - Preservatives shall not be used.

5.1.1.4 Unit packaging - Power source assemblies and subassemblies shall be


individually packaged in accordance with the unit packaging requirements of
table G5 herein and MIL-P-116, insuring compliance with the general paragraph
under methods of preservation (unit prottction) and the physical protection
requirements paragraph therein.

5.1.1.5 Intermediate packaging - Not required.

5.1.2 Level C - Assemblies and subassemblies shall be clean, dry, and indi-
vidually packaged in a manner that will afford adequate protection against
corrosion, dete:rioration, and physical damage during shipment from the supply
snurce to the first receiving activity.

5.2 Packing - Packing shall be level A, B, or C, as specified,

5.2.1 Level A - the packaged assemblies and subassemblies shall be packed in


accordance with the level A packing requirements of table G5. Boxes conforming
to PPP-B-636 shall have all seams, corners, and manufacturer's joint sealed with

tape, two inches minimum width, conforming to PPP-T-60, class 1, or PPP-T-76.

364
"5,t
E -. ,-: . . .

AloAC Cq ca;

o0r.3 0 0

C4 02 mh (a D- • " -

5. C~~ ~ 02C, 2~U

*~~ to CC
0 COc
U~ 0 00 c o= . R
R,'-
A. -* *•. ' -f •e -

044 04 4

4,.. --.

S.. • . mr!Z
Co
Q2
02 02k

o54) co
54)
2
' cr C) 1 .. =, -= _ =.. c.-
UztJPo

ad A4 r-t 04 04 *i P4

.?. F)2 , 02
6.02Co 1.21 1 .0 R -

Q2
ci
02
_ _ _ _ _ _ 4 Q__
j U ~ 0 . ~ U

0 bOeZ

cm toU (n C).)

00: U3~ 2

U4 124 0 a
~04 a4.~ A.
0 CA

: • . ,: , . . U,.,>
.. I*~04
. . . .. .. -,-..
. . .. .. . . . .
. A40 0

C: 25 - 01a3:

02B

.40 C i4 0

*~46
i...02

365
The closure, water-proofing, and banding requirements for the other level A
shipping containers shown in table G5 shall be in accordance with the appli-
cable box specification. Banding (reinforcement requirements) for ,ll fiber-
board containers (PPP-B-636 and PPP-B-640) shall be applied in accordance
with the applicable appendix using non-metallic or tape banding only.

5.2.2 Level B - The packaged assemblies and subassemblies shall be packed as


specified in 5.2.1, except that the containers shall conform to the level B
packing requirements of table G5. Box closure shall be in accordance with the
applicable box specification.

5.2.3 Level C - The packaged assemblies and subassemblies shall be packed in


shipping containers in a manner that will afford adequate protection against
damage during direct shipment from the supply source to the first receiving
activity. These packs shall conform to the applicable carrier rules and
requlations.

5.2.4 Unitized loads - Unitized loads, commensurate with the level of packing
specified in the contract or order, shall be used whenever total quantities
for shipment to one destination equal 40 cubic feet or more. Quantities less
than 40 cubic feet need not be unitized. Unitized loads shall be uniform in
size and quantities to the greatest extent practicable.

5.2.4.1 Level A - Assemblies and subassemblies, packed as specified in 5.2.1,


shall be unitized on pallets in conformance with MIL-STD-147, load type I, with
a fiberboard cap (storage aid 4) positioned over the load.

5.2.4.2 Level B - Assemblies and subassemblies, packed as specified in 5.2.2,


shall be unitized as specified in 5.2.4.1 except that the fiberboards caps
shall be class domestic.

5.2.4.3 Level C - Assemblies and subassemblies, packed as specified in 5.2.3,


shall be unitized with pallets and caps of the type, size, and kind commonly
used for the purpose and shall conform to the applicable carrier rules and
regulations.

366
i•
. . .. . .. . . . . .. . .... . .. • • .. . .. .. - .- .. . . . * .. .- .-. .o . - .
5.3 Mark i- In addition to any special mrking required by the contract or
order, each unit package, supplementary and exterior container and unitized
load shall be marked in accordance with MIL-STD-129.

5.4 General

5.4.1 Exterior contaitners - Exterior containers (see 5.2.1, 5.2.2 and 5.2.3)
shall be of a minimum tare and cube consistent with the protection required and
shall contain equal quantities of identical stock numbered items to the greatest
extent practicable.

5.4.2 U.S. Air Force reqiirements-For U.S. Air Force requirem.nts submethods
IC-3 and IC-2 with supplementary container conforming to PPP-B-636, class weather
resistant, special requirements shall be used in lieu of submethods IA-8 and
IA-14, respectively (see table G5).

-36.

,367

r"::zQ1 i.~.__2_____
o..

6. NOTES

6.1 Intended use - This specification covers power sources, which are intended
to supply either alternating current into a high voltaa high power converter
or direct current into a high voltage high power converter.

6.2 Ordering data - Procurement documents should specify the following:

a. Title, number, and date of applicable detail specification.

b. NS Part number of the desired converter.

c. Accessories to be detached fron,the power source (see 3.4.3.13 through


3.4.3.17 and 3.5.3.7 through 3.5.7'

d. Mounting principle to be employed (see d.tailed specification)

e. !.ocation of main power terminals, monitor and display cable connector


(see 3.8)

f. Weight, size al configo'-;tion (sec 3.8.11)

9. Whether shock design analysis is required (see 3.6.6)

h. Special vibraticn tests (see 3.6.7)

. Responsibility for pr-paring final manuals, quantity, date required,


and distributior- final t-Nitical manuals

j. Drawing list

k. Final drawings

'. Requirement for thermal and souind insulation (see 3.3.13)

368
.M. Requirements for inspection tests (see 4.4)

n. Level of packaging and packing required (see 5.1)

o. Reinspection date marking required (see 5.3)

6.3 Qualification - With respect to pioducts requirlng qualification, awards


will be made only for products which are at the time set for opening of bids,
qualified for nc? ;sion in the applicable qualified products list, whether or
" not such products har-• actually been so listed by that date. The attention of
the suppliers is called to this requirement, and manufacturers are urged to
arrar.•e to have the products that they propose to offer to the Federal Govern-
ment tested for qualificatltin in order ttio they my be eligible to be awarded
contracts or orders for the pm-uicts covaed.by this specification. Infomation
pertaining to qualification or products my be obtained from the Defense
"Electronics Supply Center (DESC-E),,•ayton, Ohlio 45444 (see 3.2).

6.3.1 Sultisisun of drawinig - Upon notification of qualification approval,


the w•aufacturer should provide two reproducible copies of outkine and detail
assembly drawings. Any changes i n the reproducible copies from those submitted
with the qualification sampls should be in4~cated in detail.

6.3.2 Failure of sasples - In case of failure of the sample or samples sub-


mitted, consideration will be given tW the request of the manufacturer for
additional tests only after it has been clearly shown that changes have been
made in the product which the activity respowsible for the qualification
considers sufficient to warrant additional tests.

6.4 Service test - Ser-ice tests mey be corducted v the procuring activity
and will not subject t , unit to conditions beyond the requirements of this
specification. The tests will be conducted on new units to be provided by
the procuring activity.

• %

369
6.5 Definition - All ac voltages used in this specification should be rms
values.

Notice: When Government drawings, specification, or other data are


used for any purpose other than in connection with a definit-ly related
Government procurement operation, the United States Governmnew' thereby
incurs no responsibility nor any obligation whatsoever; and the fact
that the Government may have fonwrlated, furnished, or in an, way
supplied the said drawings, specifications, or other data is not to
be regarded by implication or otherwise as in any manner licensing
the holder or any other person or corporation, or conveying any rights
:;r permission to manufacture, use, or sell any patented invention that
i.- any way be related thereto.

370
;, ._.:•
•.• ;.j • ui•.
." V
," • ,." €:.•.•
;• ,i •, --_ j.;.. .•:
•;; ,; ;, ;; ,;-•--,'- •, • ••' ,• 4"• "• •'4 --°... r• .. ,. o .. *r . ,.--. . - - ..

["-.4

4,

APPENDIX H

-. HIGH VOLTAGE TRANSFORMER AND INDUCTORS CRITERIA DOCUMENT

.4•

-4'

S~371

:•• - .- -. ".".". ." -. ".. . .. .. .. ., ...


. 4 . - . -. " "- ' .""2 . '" ' ." "' "• "". •"•.. • .'" "i 4
HIGH VOLTAGE TRANSFORMER AND INDUCTOR
CRITERIA DWCIU1ENT

This specification is approved for use by all Depart-


ments and Agencies of the Department of Defense.

1. SCOPE
1.1 Scope. This specification covers the general requirements for high voltage ,high
power and high power pulse transformers and inductors for use in airborne equipment.
This specification covers minimum weight and volume transformers and inductors
having root-mean-square (rms) test-voltage ratings of 150,000 volts or less,'and also
high power pulse transformers where the peak pulse power is greater than
10 kilowatts and the average pulse power it.greater than one kilowatt. Transformer
and inductor assemblies incorporating any other active or passive components do not
come within the scope of this specification.

1.2 Classification.

1.2.1 Type designation. The type designation shall be in the following form, and
as specified (see 3.1 and 6.1):
TF 8 R 03 HV 203

Component TIi I Frlly Envelope Identi ficatOn


(1.2.1.1) (1.2.1.2) (1.2.1.3) (1.2.1.4) and munting numb%,
dimensions (1.2.1.6)
(1.2.1.5)
1.2.1.1 Comport Transformers and inductors are identified by the two-letter
symbol "TF".

1.2.1.2 Grade. The grade is identified by a single digit denoting metal encased
or encapsulated construction, and the abilit", of the transformers or inductors
to withstand the enviromental tests of Table HI.

1.2.1.2.1 These units are sealed, metal encased with either


Grades 7, 9, 10.
separately fabricated headers or terminal!l or both. This grade does not include
units which are encapsulated in a metal shell with an opening in either end or side
of the shell, or wi-'h insulated lead wires extending through the metal shell.

372

- .
1.2.1.2.2 Grade 8. These units are encapsulated, including molded or embedded
"constructions, and units with a metal shell, open at one or both ends and filled
with encapsulant material.

TABLE Hi. GRADE

Grade 7 Grade 8 Grade 9 Grade 10


metal encap- liquid gas
Test encased sulated filled pressurized
Seal X X X X
Thermal Shock X X X X
Immersion X X X X
Moisture resistance X X X X
Vibration X X X X
Shock X X X X
Flammabil.ty --- X X ---
Salt spray (when specified) X X X X

1.2.1.3 Class. The class is identified by a single letter in accordance with Table
H2, and denotes the maximum operating temperature (temperature rise (see 4.8.11.19)
plus maximum ambient temperature) (see 6.14.2.1 and 6.14.2.3).

TABLE H2. CLASS


Symbol Maximum Ope'rating Temperature
CC

Q 85
R 105
S 130
V 155
T 170
U------------ >170, as specified (see 3.1)

1.2.1.4 Family (see 6.1). The family is identified b;, a twe-digit symbol in
acccrdance with table H3.

TABLE H3. Families,


S03
- Power transformer
04 - Power inductor
37 - Charging inductor

373
4-::: . .- .. .; ,-, .:,,: , , .. . .. , .. ...... •.. ..... . . ... . :. .. . . . : . .
1.2.1.5 Envelope and mounting dimensions. The envelope and mounting dimensions
shall be specified in the detailed specification for configuration designated HV.

1.2.1.6 Identification number. The number identifies a specific transformer or


inductor. This number will be assigned by the cognizant procurement agency when
a coordinated specification sheet is approved.
1.2.2 Connections. The winding identification and numberiri,. shall be assigned to
identify the number of phases and connections as shown in Figure Hl for examples of
three-phase and six-phase transformers.

374'

..
.....
At
THREE-PHASE TRANSFORMERS WITHOUT TAPS

0H2 X2 H2 X2
Group 1Il~~X
Angular
Displacement H1 3X 3 HI o H3 X1 X3
00
Fig. HIl-1 Fig. H14-.2

H12 X2 H2 X2
Group ~
Angular xi 0x
Dispinacement13Hi H
30X3 X3

Fig. H113 Fig. 141-4

SIX-PHASE TRANISFORMERiS WITHOUT TAPS

H12 X3 112 X3

Angular
IMaplacement K
05 X1
X3 X6

Fig, HI-S Fig. H141

[H12 34r H\ H3
X2

7
X3g

H3 X
X2 X3

4' 375
CL7 -7

2. APPLICABLE DOCUMENTS

2.1 The following documents, of the issue in effect on date of invitation for
bids or request for proposal, form a part of this specification to the extent
specified herein.

SPECIFICATIONS

FEDERAL

J-W-1f77 - Wire, Magnet, Electrical.


L-P-513 - Plastic Sheet, Laminated, Thermosetting, Paper-Base, Phenolic
Resin.
NN-P-71 - Pallets, Material Handling, Wood, Double Faced, Stringer
Construction.
QQ-S-571 - Solder, Tin Alloy; Tin-Lead Alloy; and Lead Alloy.
QQ-S-781 - Strapping, Steel, Flat and Seals.
PPP-B-566 - Boxes, Folding, Paperboard.
PPP-B-585 - Boxes, Wood, Wirebound.
PPP-l-601 - Boxes, Wood, Cleated-Plywood.
PPP-B-621 - Boxes, Wood, Nailed And Lock-Corner.
PPP-B-636 - Boxes, Shipping, Fiberboard.
PPP-B-640 - Boxes, Fiberboard, Corrugated, Triple-Wall.
PPP-B-676 - Boxes, Setup.
PPP-T-60 - Tape: Packaging, Waterproof.
PPP-T-76 - Tape, Pressure-Sensitive Adhesive Paper, (For Carton Sealing).

MILITARY

MIL-I-lO - Insulating Materials, Electrical, Ceramic, Class L.


MIL-M-14 - Molding Plastics and Molded Plastic Parts, Thermosetting.
MIL-W-76 - Wire and Cable, Hookup, Electrical, Insulated.
MIL-P-116 - Preservation-Packaging, Methods of.
MIL-W-583 - Wire, Magnet, Electrical.
MIL-P-997 - Plastic Material, Laminated, Thermosetting, Electrical
Insulation: Sheets, Glass Cloth, Silicone Resin.
MIL-F-14256 - Flux, Soldering, Liquid (Rosin Base).
MIL-P-15337 - Plastic Sheet, Laminated, Thermosetting, Glass-Cloth,
Melamine-Resin.

376

. -,•.: .... o..._ ... .-............ ,..... . .... ..--.. -. ....- ... . .-.. ..
MIL-P-15047 - Plastic-Material, Laminated Thermosetting,
,-"Sheets, Nylon Fabric Base, Phenolic-Resin
MIL-E-15090 - Enamel, Equipment, Light-Gray (Formula No.
111).

MIL-W-16878 - Wir Electrical, Insulated, High Temperature.


MIL-P-18177 - Plastic Sheet, Laminated, Thermosetting, Glass
Fiber-Base, Epoxy Resin,
MIL-B-43014 - Boxes: Water Resistant Paperboard; Folding,
Set-Up, and Metal-Stayed.
MIL-C-45662 - Calibration System Requirements.
(See supplement 1 for list of associated specification sheets (or military
standards.)

STANDARDS

MILITARY

MIL-STD-129 - Marking for Shipment and Storage.


MIL-STD-147 - Palletized Unit Loads on 40" x 48w Pallets.
MIL-STD-202 - Test Methcls for Electronic and Electrical
Component Parts.
MIL-STD-454 - Standard, General Requirements for Electronic
Equipment.
MIL-STD-461 - Electromagnetic Interference Characteristics
Requirements for Equipment.
MIL-STD-810 - Environmental Test Methods.
MIL-ST06-1285 - Marking of Electrical and Electronic Parts.

(Copies of specifications, stadards, drawings, and publications requi;,ed by


suppliers in connctton with specific procurement functions should be obtained
from the procuring activity or as directed by the contracting officer.)

2.2 3ther pulications. The following document forms a part of this


specification to the exzcnt specified herein. Unless otherwise indicated, the
issue in effect oii date of invitation for bids or r'ew.st for proposal shall
apply.

37-

t . . . . . . • . t . - . . - ° . . o . . . . . . . - - ..-- .1 .-
"NEMA Publication No. 109 - IEEE-EEI-NEMA Standard Basic Insulation Level.

ASTM D1868 - Detection and Measurement of Discharge (Corona) in


Evaluation of insulation Systems.

ASTM D3382-75 Measurement of Energy ant4 Integrated Charge


Transfer Due to Partial Discharges (Corona) Using
Bridge Techniques.

ASTM D3426 Die.:..tric Breakdown Voltage and Dielectr=z


Strength of Solid Electrical Insulating Materials using
Impulse Waves.

Institute of Electrical and Electronic Engineer-


IEEE STD-4, IEEE Standard Techniques for High Voltage Testing
IEEE ý.TD-28,1975 Surge Arresters for Alternating Current Power Circuits

American National Standard - C57.12.00-1973 - General '" quirements for


Distribution, Power, and R-egulating Transformers.

APPENDIX A - High Voltage Cable Criteria Document


APPENDIX B - High Voltage Cable Assembly Criieria Document
APPEN4DIX D - High Voltage Connector Criteria Document
APPENDIX F - High Voltage Power Characteristics Criteria
Document

NATIONAL BUREAU OF STANDARDS

Handbook. H28 - Screw-Threads Standmds for Federal Services

(Application for copies should be addressed to tle Superintendent of Documer.ts,


Governmenf Prin'ing Office, Washington, D.C. 20402.)

37

.• 378
-,•. - ,. : ' ' . - , .. ., - - , . - ., . ,,. ., ' . . , .. . - . . ,1 ' ' - , - - .
3. REQUIREMENTS

• •3.1 Specification sheets.


The individual part requirements shall be as specified
herein and in accordance with the applicable detailed specification sheets. In
the event of any conflict between this specification and the detailed specification
sheet, the latter shall govern (see 6.1).

3.2 Qualification. Transformers and inductors covered by specification sheets


furnished under this specification shall be products which are qualified for
listing on the applicable qualified products list at the time set for the opening
of bids (see 4.5 and 6.2). When there are no products listed or approved for
listing on the qualified products list, the qualification requirement is waived
only by the preparing activity; and procuring activities shall invoke first
article inspection.
3.3 First article. Transformers and inductors not covered by specification

sheets shall be as specified In the applicable complementary document (see 6.1.2).


These products shall have been tested and passed first article inspection in 4.6
and 6.3. This inspection consists of meeting all of the qualification tescs of
..:::.. 4.5 through 4.5.1.3, inclusive and table H5.

3.3.1 Information to be furnished with first article sample. The appli,'able


information outlined in 6 1.2 shall be furnished with the first article sample,
together with any other pertinent information as required by the Government.

3.4 Materials. The materials shall be as specified herein; however, when a


definite material is nct specified, a material shall be used which will enable
the transformers and inductors to meet the performance requiremE'its of this
specification. Acceptance or approval of any constituent material shall not
be construed as a guaranty of the acceptance of the finished product.

3.4.1 Substitution of materials. If the supplier desires to substitute another


material for a specified material or fabricated part, he shall submit a statement
to the Government describing the proposed substitution, together with evidence
to substantiate his claims that such substitute is suitable. At the discretion
of the Government, test samples may be required to prove the suitabi"ity of the
proposed substitute. Before such substitutions are made, approval for each
substitution shall be obtained in writing from the Government.

379
S..... ~~.. . . • .-. . - • "- -" •.*• -
.•,,., ,,,......
.,, ,,,~~~~~.. ,...... ...- ,.--..........-......... . ..-. .- :'........:...:...:.
3.4.2 Flanmmable materials. Insofar as practicable, materials used in the construc-
tion of transformers and inductors shall be nonflammable and nonexplosive.

3.4.3 Corrosive materials.Corrosive materials used in any of the manufacturing


processvfs shall be removed or neutralized so that no corrosion will result from
such use. Insofar as practicable, materials used ini the construction of trans-
formers and inductors shall be noncorrosive.

3.4.4 Insulating materials.

* 3.4.4.1 Laminated phenolic. Laminated phenolic materials shall conform to


.*. MIL-P-997, L-P-513, MIL-P-15037, or MIL-P-15047. When electrical characteristics
are involved, only natural uncolored materials shall be used.

3.4.4.2 Molded phenolic or nelamine. Molded phenolic or melamine materials shall


conform to MIL-M-14.

3.4.4.3 Ceramic (external use). Cerar c materials shall conform to MIL-I-l0.

3.4.4.4 Laminated plastic sheet. Laminated plastic sheet, epoxy, shall conform
to MIL-P-18177.

3.4.5 Wire. Irternal v-iring of a transformer or iiliuctor is considered to be all the


interconnectitig wiring beyond the point where the pov.r supply enters the enclosure.

3.4.5.! Magnet wire. Magnet wire shall conform to and be of the types and sizes
specified in Federal specification J-W-1177 and MIL-W-58Z Goyernment approval
shall be required when other t.)es and sizes of magnet wire an? used.

3.4.5.2 Insulated wire. When insulated wire is used as wire terminals, the wire
shall be of the types and sizes covered in MIL-W-76, MIL-W-16878 or the H.V. cable
criteria document. Government approval shall be required when other types and
sizes of insulated wire are used as terminals.

3.4.5.3 Wire support. All wire, cable and buses shall be supported and arranged
so they will withstand abrasion, flexing, and vibration. Clamping shall be such
that it will n(ic damage the insulation.

3.4.6 Solder and soldering flux. Solder, when used, shall be in accordance with
QQ-S-571. Soldering flux shall be in accordance with MIL-F-14256.

380
3.4.7 Screws, nuts, bolts, and washers. All mounting and terminal screws, nuts,
bolts, and washers shall be of corrosion-resistant material or shall be protected
against corrosion.

3.5 Design and construction.

3.5.1 Mounting and terminal screws and mounting inserts. Screw threads shall be I
Class 2A or 2B, as applicable (see 3.1), in accordance with Handbook H28. External
screw threads, class 2 fit, shall, after receiving a finish,,be capable of
accepting a nut of class 2B fit and internal screw threads, class 2 fit, shall,
after receiving a finish, be capable of accepting a screw of class 2A fit.
Maximum installation torque shall be as specified in the detailed specification.
Nuts shall rin down to within two threads of mounting surface or washer surface.

3.5.2 Terminals (see 3.1 and 6.1.2).

3.5.2.1 Solder terminals (see 4.8.2.2). Solder terminals may be of any shape
and shall be capable of complying with solderability requirements of this speci-
*: fication. The height of the solder terminal shall be considered as the maximum
distance from the terminal mounting surface to the highest point, including the
additional height obtained if semiflexible terminals are straightened. It is
not intended that the "hook" in the hook-type terminal be straightened from its
normal hooked position. The type of terminal and the maximum size of wire which
the terminal will accept externally shall be as specified in the detailed speci-
fication (see 3.1 and 6.1.2).
3.5.2.2 Case as terminal. When the case is used as a terminal, any protective
coating applied to the mounting surfaces shall be such as to provide a direct
conducting path for an electric current from the case to the surface on which it
is mounted.

3.5.2.3 Bushings. The basic insulation level of line bushings shall be as


specified in paragraph 4.8.13.7.

3.5.2.4 Terminal insulators. Terminal insulators shall be glass or ceramic.

3.5.2.5 Connectors. Connectors shall be hermetically sealed, circular threaded,


as specified in the high voltage criteria document, Appendix D.

381
3.5.2.6 Screw terminals. When . 3cified (see 3.1, 6.1.1 and 6.1.2), external
screw terminals shall be supplied with two nuts, two flat washers, and one lock-
washer. For cased units, the height of the terminal assembly shall be the distance
from the free end of the screw to the terminal mounting surface. The type of

terminal, size of screw thread, and the exposed length of threads +.062 inch shall
be as specified (e.g.. screw,O.164-32 UNC xO.375. (see 3.1 and 6.1.2).

3.5.2.7 Corona protected bushing insulator.


When specified (see 3.1 and 6.1.2),
terminals shall be supplied with a corona suppressor where the terminal and
terminal hardware are shielded by an angle of at least 30 degrees by corona
suppressor cavity. Terminal hardware shall consist of two nuts, one flat washer

and one lock washer,or shall consist of one flat washer, one lock washer and one
cap screw. The terminal post shall not have external threads below the corona
suppressor in the bushing. Terminal pcst finish shall be 100 microns or smoother.
The height of the terminal assembly shall be the distance from the top of the
corona suppressor to tV- 'erminal mounting surface. The type of terminal shall
be specified (see 3.1 and 6.1.2).

3.5.3 Lifting, moving, and jacking facilities.

3.5.3.1 Safety Factor.


Lifing, moving, and jacking facilities shall be designed
to provide a safety factor of 5. This safety factor is the ratio of the ultimate
stress of the material used to the working stress. The working stress is the
maximum combined stress developed in the lifting facilities by the static load
of the component being lifted.

3.5.3.2 Lifting facilities. Lifting facilities shall be provided for lifting


the cover separately, and also for lifting the core and coil assembly from the
housing using one to four lifting cables.
Facilities for lifting the complete transformer (with the cover securely fastened
in place) shall be provided. Lifting facilities shall be designed for lifting with
one to four slings at a maximum angle of 30 degrees with respect to the vertical.

The bearing surfaces of the lifting facilities shall be free from sharp edges and
shall be provided with a hole having a minimum diameter of 13/16 inch (20.6 mm)
for guying purposes.

382
3.5.3.3 Moving facilities. The base of the transformer shall be of heavy
plate or have members forming a rectangle that will permit rolling in the direc-
tions of the centerlines of the segments. IV

3.5.3.4 Jacking facilities. Jacking facilities shall be located near the


extreme ends of the corners of the case.

3.5.3.5 Mounting. The points of support shall be so that the inductive unit
will withstand the variable orientation of the airplane.

3.5.3.6 Mounting studs. When specified (see 3.1, 6.1.1 and 6.1.2), external
mounting studs shall be provided with a flat washer and locknut, or with a
Flat washer, lockwasher, and a nut.

3.5.4 Internal wire leads. Internal wire leads shall be attached to ihe coils,
bushings, and other internal components and terminals or case by soldering,
welding, brazing, or other method (e.g., lead-sweating, nylon-coated wires
or bolts) in such a manner as to provide adequate electrical connection and
mechanical strength. Where soft solder is used to provide the electrical con-
nection, wire leads shall be anchored mechanically.

3.5.5 Cores and coils shall be secured rigidly to


Core and coil mounting.
prevent any permanent change in the relative position of the parts. The means
of securing the core and coil to the devices for mounting the transformer or
inductor in the equipment (e.g., studs, lugs, inserts, brackets, etc.) shall
not depend on soft solder alone for mechanical strength, nor shall the trans-
mission of the mechanical load of the core to the mounting device depend only
on soft solder. When specified (see 3.1 and 6.1.2), the core shall be grounded
to the case or shall be electrically accessible.

3.5.6 Paint composition and color. When a paint finish is specified (see
3.1 and 6.1.2), the color of the paint shall be light gray, semigloss, formula
No./1111 as specified in MIL-E-15090 or as specified in the detailed specifi-
cation. Unless otherwise specified (see 3.1 and 6.1.2), the manufacturer shall
omit paint from the mounting area surface.

3.5.7 Potting, filling, or encapsulating material. The amount and coverage


of potting, filling, or encapsulating material used shall be essentially the
same for all units of a specific design. Potting, filling, or encapsulating
material shall not flow from the case of the transformer or inductor during
any of the a*•* able tests.
383
3.6 Solderability. When transformers and inductors are tested as specified
in 4.8.2, they shall meet the applicable criteria for terminal evaluation in the
test method.

3.7 Resistance to solvents. When transformers and inductors are tested as


specified in 4.8.3, there shall be no evidence of mechanical damage and the
markings shall remain legible. The paint or exterior finish shall not soften,,
peel or show other signs of deterioration.

3.8 Thermal shock. P'hen transformers and inductors are tested as specified
in 4.8.4, there shall be no leakage of filling material, no evidence of other
physical damage such as cracks, bursting, or bulging of the case or coi*rosion
affecting the mechanical or electrical operation.

3.9 Resistance to soldering heat. When transformers and inductors are tested
as specified in 4.8.5, there shall be no softening of the insulation or loosening
of the windings or terminals.

3.10 Terminal strength. When transformers and inductors are tested as specified
in 4.8.6, there shall be no evidence of loosening or rupturing of the terminals,
or other mechanical damage. Bends shall not be considered as damage unless
usu-face cracking is evident. Except for flexible leads, there shall be no
rotation of the terminals. Rotation of the external portion of the metallic
portion of a "hook" type terminal of less than 10 degrees shall not con-
stitute a failure.

3.11 Seal (see 4.8.7).

3.11.1 Liquid-filled units. When transformers and inductors are tested as


specified in 4.8.7.1, there shall be no evidence of liquid leakage.

3.11.2 Gas-filled units. When transformers and inductors are tested as


specified in 4.8.7.2, the leak rate shall not exceed IxlO- 8 standard atmosphere
cubic centimeter per second (atm cm3 /s).

3.11.3 Pressure-vacuum transducer. A pressure-vacuum transducer shall be fur-


nished for transformers of the sealed-tank and gas-oil-seal constructions.

384
v7 5-

3.11.4 Liquid temperature transducer. A liquid temperature transducer shall


be furnished for trarsformers of the sealed tank liquid filled construction. F

3.11.5 Pressure-.vacuum bleeder. A pressure-vacuum bleeder device shall be


set to operate at the iroximum operating pressure (positive and negative)
indicated on the nameplate. Transformer effluent gases/liquids
shall be ported overboard the aircraft.

3.11.6 Tanks. Tanks shalh be designed for vacuum filling in the field.
A pressure relief device shall be provided on the cover. Maximum operating
pressures (positive and negative) for which the transformer is to be operated
shall be indicated on the nameplate.

3.11.7 Fans, pumps and control. The equipment for automatic control of fans "
or pumps for forced air cooled or liquid cooled transformers shall be thermally
controlled with a manual override switch in parallel with the automatic control.
Contacts and sensors shall be enclosed inside the transformer tank.

3.11.8 Surge Arestors. When specified, a surge arrestor ground pod consisting
of a tank ground pod, mounted near the high voltage terminals shall be available
for surge protection.

3.11.9 All other units. When transformers and inductors are tested as specified
in 4.8.7.3, there shall be no continuous flow of air bubbles or leakage of
compound from the body of the units. When the coil is individually encapsulated, j
bubbles from the space between the coil and laminations shall not be considered
a failure provided the seal of the coil has been previously tested.

3.12 Dielectric withstanding voltage. When transformers and inductors are


tested as specified in 4.8.8, there shall be no evidence of arcing, flashover,
breakdown of insulation, or damage Jetermined by visual inspection and reduced
insulation resistance and increased partial discharge magnitudes.

3,13 Induced voltage. When transformers and inductors are tested as specified
in 4.8.9, there shall be no evidence of continuing arcing or breakdown of
insulation, nor shall there be any ahrupt changes in the input current, or Q, as
'V
applicable.

385
*.... .7 Wi. .. I
.1

3.14 Insulation resistance. When measured as specified in 4.8.10, the minimum


insulation resistance shall be greater than the value specified for the insulation
•system
* in the applicable specification.

'3.15 Electrical characteristics. When transformers and inductors are tested as


specified in 4.8.11, the applicable electrical characteristics and tolerances
shall be as specified (see 3.1 and 6.1.2).

." 3.15.1 Polarity. Transformer winding polarity shall be determined as


*. specified in 4.8.11.9, or as specified (See 3.1 or 6.1.2).

3.15.2 Turns ratio. When a transformer has taps or multiple windings, the
turns ratio shall be determined for all taps as well as for the full windings
as outlined in 4.8.11.12 or as specified (see 3.1 and 6.1.2).

3.15.3 D.C. resistance and resistive unbalance. When transformers and inductors
are tested as specified in 4.8.11.3, the d.c. resistance shall be measured at
or corrected to 20°C. The resistive unbalance of center tapped windinns in
percent (Rl - R2 ) shall be computed.

- 3.15.4 Primary impedance. When transformers are tested as specified in 4.8.11.6,the


primary winding impedance shall be measured with secondaries loaded to normally
loaded impedance, including d.c. currents flowing in the windings.

3.15.5 Core loss. When transformers are tested as specified in 4.8.11.14,


excitation losses consisting principally of the transformer core losses shall
be measured or as specified (see 3.1 and 6.1.2).

3.15.6 Insulation power loss. Winding insulation losses for transformers and
inductors shall be tested as specified in 4.8.11.15, or as specified (see 3.1
and 6.1.2).

3.15.7 Bushings. When tests are required on bushings separately from the
transformers, the tests shall be as specified in 4.8.11.16.

3.15.8 No load. When transformers are tested under no load conditions,


measurements shall be made with the secondary windings open circuited, as outlined
in 4.8.11.1 or as specified (see 3.1 and 6.1.2).

* . . . . 386
*4.
F

3.15.9 Efficiency and regulation. When transformers and inductors are tested
as specified in 4.8.11.2 efficiency and regulation shall be measured at 50%
load ,full load and 125% load. Load impedance shall include but not be limited
to power factors of 1.0, 0.8 lag and 0.9 lead. The exact regulation is given
r_+_p)2 +_x+_2_-Iforlaggingloads
h(r + p) 2 + (x + q) 2 -I for lagging loads
r
4(r + p)2 + (x - q _
-l for leading loads
where
p = power factor of load
q +-/1
x = leakage reactance of the transformer
r = dc resistance of the transformer
3.15.10 Short circuit. Short circuit leakage impedance, primary to secondary

and half-winding to half-winding shall be measured as outlined in 4.8.11.13,


or as specified (see 3.1 or 6.1.2).

3.15.11 Inductance and inductive unbalance. Inductance and inductive unbalance


of transformers and inductors shall be calculated or measured at operating
frequency with the specified d.c. current applied, as specified in 4.8.11.4,
or as specified (see 3.1 or 6.1.2).

3.15.12 Harmonic distortion. When transformers or inductors are tested as


specified in 4.8.11.5, the harmonic distortion shall be measured or computed,
or as specified (see 3.1 and 6.1.2).

3.15.13 Self-resonant frequency. The self resonant frequency of transformers


and inductors shall be measured as specified in 4.8.11.7, or as specified
(see 3.1 or 6.1.2).

3.15.14 Storage factor. When inductors are tested as specified in 4.8.11.10,

the energy storage factor shall be measured or computed, or as specified


(see 3.1 or 6.1.2).

3.15.15 Wave shape. Transformers or inductors having non-sinusoidal wave


h-. shapes shall be tested as specified in 4.8.11.11, or as specified (see 3.1 or
6.1.2).

387

" " = , " ."• ,


.* ° . .°5-
. - S , ° . * -°
" -"""•°° • * - , S - S
3.16 Temperature rise. When transformers and inductors are tested as speci-
fied in 4.8.11.19, the temperature rise of any windirng above the specified
maximum ambient temperature (see 3.1 and 6.1.2) shall not exceed the value
specified (see 3.1 and 6.1.2), and there shall be no evidence of ph; "'al
damage.

3.17 Partial discharges (when specified, see 3.1 and 6.1.2). When transformers
and inductors are tested as outlined in 4.8.12 or as specified (see 3.1 and
6.1.2), the partial discharge maximum magnitudes shall rot exceed the following
limits as rated voltage.

Voltage Limit Counts/Minute Not to Exceed


KV PC/KV Over Limit PC/KV

DC 1 1 5
AC 2 10 5

3.18 Pulse. When transformers and inductors are tested as outlined in 4.8.13 or as
specified (see 3.1 and 6.1.2), the pulse voltage shall have a wave shape as defined in
4.8.13. Pulse tests shall be made without excitation. .

3.18.1 Thermals not being tested. Neutral windings, low voltage windings and
instrumentation and control equipment shall be grounded during pulse tests.

3.19 Electromagnetic compatibility. When transformers or inductors are tested as


specified in 4.8.11.8, the assembly shall have a shielding e .fectiveness of 15 dB minimum,
and electrical field effectiveness of 45 dB minimum.

3.20 Altitude. When tested as specified in 4.8.8.2, the transiormer or inductor shall meet
the partial discharge and voltage breakdown requirements (see 3.12 and 3.17). Any

evidence of dielectric breakdown, arcing, or flashover within the transformer envelope


shall be cause for rejection.

3.21 Salt spray (corrosion) (when specified, see 3.1 and 6.1.2). When transformers and
inductors are tested as specified in 4.814, there shall be no evidence of corrosion as
exhibited by any visible degradation of the surfaces that can be attributed to flaking,
pitting, blistering or otherwise loosened protective coating or metal surface.

-BB

Sq388 S
3.22 Vibration. When transformers and inductors are tested as specified
in 4.8.15, there shall be no leakage of filling material, no evidence of
orier physical damage such as cracks, bursting, or bulging of the case.

3.23 Shock. When transformers and inductors are tested as specified in


4.8.16, there shall be no leakagu of filling material, no evidence of other
physical damage such as cracks, bursting, or bulging of the case.

3.24 Vitiding continuity. When transformers and inductors are tested as


spec:.ied in 4.8.17, all windings shall be electrically continuous.

3.25 Immersion. When transformers and inductors are tested as specified


in 4.8. 1 j, there shall be no lea:ýtge of filling material, no evidence of
other physical da'.age such as cracks, bursting, or bulging of the case or
corrosien affecting the mechanical or electrical operation.
.2r Moisture resistance. When transformers and inductors are tested as
,'2(;ied in 4.8.19, there shall be no leakage of filling material, no
:dence of other physical damage such as cracks, bursting, or bulging of
the case or corrosion affecting the mechanical or electrical operation. W"

3.27 Overload. When transformers and inductors are tested as specified


in 4.8.20, there shall be no leakage uc filling material, no evidence of
other physical damage such as crac;,s, bursting, or bulging of the case.

3.28 Visual and machanical examination (post test). When transformers and
inductors are examined as specified in 4.8.1.1.1, not more than 10 percent of
the surface shall have peeling, flaking, chipping, cracking, crazing, or other
inoairment of the protective coating. There shall be no leakage of the filling
material, no evidence of other physical damage, such as cracks, bursting,
or bulging of the case or corrosion affecting the mechanical or electrical

operation of the units.

3.29 Flammability (grade 5). When transformers and inductors are tested as
specified in 4.8.21, there shall be no evidence of violent burning which results
in an explosive-type fire, and the coating material used on the transformers and
inductors shall be self-extinguishing. A transformer or inductor shall not be
be

389

°o-' "•
* •. . ". . . . .°+"%. . . - ° . . o+ . - + . . ,. .,.
considered to have failed, in the event that it is consumed by the applied
flame, unless dripping of flaming material or an explosive-type flame has
occurred. A trdnsformer or inductor shall be considered to have failed only
if an explosion of dripping of flaming material occurs, an explosive-type
flame is produced, or if visible burning continues beyond the allowable
duration of 3 minutes after removal of the applied flame. Material will be
considered self-extinguishing if the following conditions are met: r
(a) The duration of visible flame does not exceed 3 minutes after removal
of the applied flame.
(b) There is no explosion, nor any violent burning which results in an
explosive-type flame.
(c) Ihere is no dripping of flaming material from the transformer or
inductor under test.

3.30 Life.
When transformers and inductors are tested as specified in 4.8.22, -"
there shall be no evidence of physical or electrical damage as indicated by
an open circuit (a break in the continuity of any electrical circuit within the
transformer or inductor being tested) or short circuit occurring within the
transformer or inductor (such as shorted turns or faulty insulation between r -

layers, between turns, between windings, between windings and case or core,
or between windings and shield). In addition, transformers and inductors shall
meet the following requirements:
(a) Insulation resistance - Shall be as specified in 3.14.
(b) Dielectric withstanding voltage (at atmospheric pressure) - Shall be
as specified in 3.12.
(c) Induced voltage - Shall be as specified in 3.13.

The electrical characteristics shall remain within the limits detailed in the -4-
detailed specification. All transformers and inductors furnished under this
specification shall have a life expectancy as specifieo in the detailed specification.

3.31 Fungus. All external materials shall be nonnutrient to fungus growth o


or shall be suitably treated to retard fungus growth. The manufacturer shall
certify that all external materials are fungus resistant (see 4.8.23) or shall
parform the test specified in 4.8.23. There shall be no evidence of fungus
growth on the external surfaces. t

390

t*.*, *~ -. - *.-*
. * - ....
........... *
3.32 Marking. Transformers and inductors shall be marked with the military
part number, manufacturer's part number, manufacturer's code symbol, terminal
identification and date code and lot symbols in accordance with method I,
MIL-STD-1285 (see 3.29.1 through 3.29.6). Markings shall remain legible
after all tests. Any markings of a classified nature shall not be included.
Unless otherwise specified (see 3.1 and 6.1.2), the following additional
information as applicable to the individual families, shall be ^
included.

3.32.1 Family 03. Rated voltage and frequency of primary, rated voltages and
currents of secondaries, working voltages to ground for each winding, working
voltages between windings whenever they exceed any of the applicable working
voltages to ground, and the altitude if greater than 10,000 feet.

3.32.2 Families 04, 37. Rated inductance at nominal frequency and voltage,
ac voltage and frequency, dc current, dc resistance, working voltages to ground,
working voltages between windings whenever they exceed any of the applicable
working voltages to ground, and the altitude if greater than 10,000 feet.

SWi3.32.3 Families 40 and 41. Maximum control current, impedance, impedance


variation, rated voltages and frequency (as applicable), maximum feedback current
(if any), bias current (if any), operating power level, working voltages to
ground, and working voltages between windings whenever they exceed any of the
applicable working voltages to ground, and the altitude if greater than S
10,000 feet.

3.32.4 Terminal identification. Unless otherwise specified (see 3.1 and 6.1.2),
terminals shall be identified by appropriate numbers as shown in Figure HI.

3.32.5 Serial Number. Each transformer and inductor shall have a serial number.
All design and test data shall be traceable to the serial number.

3.33 Transformers and indUctors shall be processed in such a


Workmanship.
of 3.3, 3.4
manner as to be uniform in quality and shall meet the requirements
and 3.5 as applicable, and shall be free of defects that will affect life
serviceability or appearance.

391
4. QUALITY ASSURANCE PROVISIONS

4.1 Responsibility for inspection. Unless otherwise specified in the contract or


purchase order, the supplier i . (:asible for the performance of all inspection
requirements as specified herein. Except as otherwise specified in the contract or
order, the supplier may use his own or any other facilities suitabe for the per-
formance of the inspection requirements specified herein, unless disapproved by the
Government. The Government reserves the right to perform any of the inspections
set forth in the specification where such inspections are deemed necessary to assure
supplies and services conform to prescribed requirements.

" 4.1.1 Test equipment and inspection facilities. Test and measuring equipment and
inspection facilities of sufficient accuracy, quality and quantity to permit per-
formance of the required inspection shall be established and maintained by the
inspection facility. The establishment and maintenance of a calibration system to
control the accuracy of the measuring and test equipment shall be in accordance
with MIL-C-45662.

4.2 Classification of inspections. The inspections specified herein are classified


as follows:
(a) Materials inspection (see 4.3).
(b) Qualification inspection (see 4.5).
(c) First article inspection (see 4.6).
(d) Quality conformance inspection (see 4.7).

4.3 Materials inspection. Materials inspection shall consist of certification


supported by verifying data that the materials listed in table H4 used in fabricating
the transformers and inductors, are in accordance with the applicable referenced
specifications or requirements prior to such fabrication.

TABLE H4. Materials inspection.


Requirement
Materials paragraph Applicable specification
Insulating material:
Laminated phenolic 3.4.4.1 MIL-P-997, L-P-513,
MIL-P-15037, or MIL-P-15047
Molded phenolic or melamine- 3.4.4.2 MIL-M-14

Ceramic (external use)- - - 3.4.4.3 MIL-I-IO


Laminated Plastic Sheet- - 3.4.4.4 MIL-P-18177
Wire:
Magnet wire ----------- 3.4.5.1 J-W-1177
Insulated wire
--- --- --- -- 3.4.5.2 MIL-W-76 or MIL-W-16878
wir ,
**;* .: : .. * * * **
4.4 Inspection conditions. Unless otherwise specified herein, all inspections
shall be performed in accordance with the test conditions specified in the "GENERAL
REQUIREMENTS" of MIL-STD-202 and MIL-STD-454.

4.4.1 Test frequency.


When a test frequency is specified herein, the frequency
used shall be within +2 percent of the nominal value. The test frequency of trans-
formers and inductors shall be the geometric mean of the specified frequency range
or a lower value selected by the manufacturer.

4.4.2 Test voltage. For transformers and inductors, the rated rms voltage at the
minimum frequency of the specified frequency range shall be applied at the rated duty
cycle (e.g., transformers rated at 50/60 Hertz (Hz) shall be tested at 50 Hz; trans-
- formers and inductors rated at 60 Hz +10 percent shall be tested at 60 Hz). When
rated primary voltages are specified with a tolerance (see 3.1 and 6.1.2), the test
voltage shall be the rated vol•age (e.g., 115 +10 volts shall be tested at 115 volts).
For two terminal primary windings where the rated primary voltage is specified as a
range, the test voltage shall be the arithmetic mean of the range. For multitap
primary windings where a range of voltages are specified, the test voltage shall be
applied to the highest voltage in the range and applied to the appropriate terminals
Ii •(e.g., 105 to 125 volts shall be tested at 125 volts). For dielectric withstanding
voltage tests, the peak of the voltage applied shall not exceed by more than 5 per-
cent the peak of the pure sine voltage.

4.5 Qualification inspection. Qualification inspection shall be performed at a


laboratory acceptable to the Government (see 6.2) on sample units produced with
equipment and procedures normally used in production.

4.5.1 Qualification of transformers and iniductors based on complete testing.

4.5.1.1 Sample size, A sample of one unit shall be comprised of a high voltage
transformer or inductor and shall be submitted for inspection.

4.5.1.2 Inspection routine. The sample units shall be subjected to the inspections
specified in table K5, in the order shown and as specified in paragraph 20to this
specification.

4.5.1.3 Failure.
One or mcre failures of the specified qualification inspection
tests listed in Table H5 shall be ca'se for ,efusal to grant qualification approval.

39
S393 w

** * * . . * . * -. . _.* ... * :. * * *
5°.
°U

4.5.2 Qualification inspection of transformers and inductors based on similarity.


Qualification inspection shall be performed only on those transformers and in-
ductors which meet the requirements of 20.2 of the appendix.

4.5.2.1 Sample size. A sample of one unit shall be comprised of a high voltage
transformer- or inductor and shall be submitted for inspection.

4.5.2.2 Inspection routine. Sample units shall be subjected to the qualification


inspection in table H6, in the order shown.

- 4.5.2.3 Failure.
One or more failures of the specified qualification inspection
*: for transforners and inductors similar to transformers and inductors that have been
qualified in tests listed in Table H6 shall be cause for refusal to grant qualifi-
cation approval
TABLE H5. Qualification inspection.
Grade Requirement Method
Examination or test 7 8 9 10 paragraph paragraph
Group I
Solderability 1/ X X X X 3.6 4.8.2
Resistance to solvents X X X X 3.7 4.8.3
Group II
Thermal shock (when specified) V
(25 cycles) X X X X 3.8 4.8.4
Visual and mechanical examina-
tion (external) X X X X 3.1, 3.4 to 3.4.4.4 incl., 4.8.1
3.5 to 3.5.2.7 incl., 3.5.3,
3.5.7, 3.32 and 3.33 4
Resistance to soldering heat X X X X 3.9 4.8.5
Terminal strength X X X X 3.10 4.8.6
Seal X X 3.11 to 3.11.2 incl.4.8.7
Pressure vacuum transducer X X 3.11.3 4.8.7.3.1
Liquid temperature transducer X 3.11.4 4.8.7.3.1
Pressure vacuum bleeder X X 3.11.5 4.8.7.3
Tanks X X 3.11.6 4.8.7.3
Fans, Pumps and Control X X X X 3.11.7 4.8.7.3.2
Surge arrestors X X X X 3.11,8 4.8.7.3.3
Diel ectric withstanding voltage:
At atmospheric pressure X X X X 3.12 4.8.8.1
At altitude X X X X 3.12 4.8.8.2
Induced voltage X Y X X 3.13 4.8.9
Insulation resistance X X X X 3.14 4.8.10
Polarity X X X X 3.15.1 4.8.11.9
Turns ratio X X X X 3.15.2 4.8.11.12
DC resistance and X X X X 3.15.3 4.8.11.3
resistance unbalance

394'
TABLE H5. Qualification inspection (cont.).
Grade Requirement Method
Examination or test 7 8 9 10 paragraph paragraph

"Primary impedance X X X X 3.15.4 4.8.11.6


Core loss X X X X 3.15.5 4.8.11.14
Insulation power loss X X X X 3.15.6 4.8.11.15
Bushings X X X X 3.15.7 4.8.11.16
No load X X X X 3.15.8 4.8.11.1
Efficiency and regulation X X X X 3.15.9 4.8.11.2
Short circuit X X X X 3.15.10 4.8.11.13
Inductance and inductance X X X X 3.15.11 4.8.11.4
unbalance
Harmonic distortion X X X X 3.15.12 4.8.11.5
Self resonant frequency X X X X 3.15.13 4.8.11.7
Storage factor X X X X 3.15.14 4.8.11.10
Wave Shape X X X X 3.15.15 4.8.11.11
Temperature rise X X X X 3.16 4.8.11.19
* Partial discharge X X X X 3.17 4.8.12
"Pulse X X X X 3.18 4.8.13
Terminals not being tested X X X X 3.18.1 4.8.11.17
"Electromec-netic compatibility X X X X 3.19 4.8.11.8
Al tituc., X X X X 3.20 4.8.11.18

Group III

Salt spray (when specified) X X X X 3 21 4.8.14


Vibration X X X X 3.22 4.8.15
Shock X X X X 3.23 4.8.16
Dielectric withstanding voltage:
At reduced voltage X X X X 3.12 4.8.8.3
Thermal shock (10 cycles) X X X X 3.8 4.8.4
Imriersion X X 3.25 4.8.18
Moisture resistance X X X X 3.26 4.8.19
Dielectric withstanding voltage:
At reduced voltage X X X X 3.12 4.8.8.3
Overload X X X X 3.27 4.8.20
Dielectric withstanding voltage:
At reduced voltage X X X X 3.12 4.8.8.3
Visual and mechanical examin-
ation (internal) X X X X 3.1, 3.4 to 3.4.4.4 incl. 4.8.1.2
Flammabil ity X 3.5.3, 3.5.4.23.5.6 & 3.32 4.8.21
Group IV

Life X X X X 3.30 4.8.22


Dielectric withstanding voltage:
At reduced voltage X X X X 3.12 4.8.8.3
* Insulation resistance X X X X 3.14(c) 4.8.10
Induced voltage X X X X 3.13 4.8.9
Partial discharge X X X X 3.17 4.8.12
Visual and mechanical examin-
• ation (external) X X X X 3.1, 3.4 to 3.4.4.4 incl., 4.8.1.1
"3.5 to 3.5.2.7 incl. 3.5.3,
3.5.7, 3.32 and 3.33

395 w
"TABLE H5. Qualification inspection (cont.)
Grade Requirement Method
Examination or test 7 8 9 10 paragraph paragraph

Group V
Fungus 2/ X X X 3.31 4.8.23 r
I/ Solderable type terminals only: If the soldering iron method (4.8.2.2) of the
solderability test is performed, then the resistance to soldering heat test
(4.8.5.2) need not be performed.
21/ Test shall not be performed if the manufacturer provides certification that all r
external materials are fungus resistant.

TABLE H6. Qualification inspection for transformers and inductors similar


to transformers and inductors that have been qualified.
Requirement Method
Examination or test paragraph paragraph
Visual and mechanical examination 3.1, 3.4 to 3.4.4.4 4.8.1.1
(external) incl., 3.5 to 3.5.2.7
incl., 3.5.3, 3.5.7,
3.11.1 to 3.11.8 incl.
3.32 and 3.33
Dielectric withstanding voltage
At atmospheric pressure 3.12 4.8.8.1
At barometric pressure (when applicable) 3.12 4.8.8.2 V
Induced voltage 3.13 4.8.9
Insulation resistance 3.14 4.8.10
Electrical characteristics 8.'8" 0
S20
Polarity 3.15.1 4.8.1.9
Turns ratio 3.15.2 4.8.11.12
DC resistance and resistance unbalance 3.15.3 4.8.11.3
Primary impedance 3.15.4 4.8.11.6
Core loss 3.15.5 4.8.11.14
Insulation power loss 3.15.6 4.8.11.15
Bushings 3.15.7 4.8.11.16
No load 3.15.8 4.8.11.1
Efficiency and regulation 3.15.9 4.8.11.2
Short circuit 3.15.10 4,8.11 .13
Inductance and inductance unbalance 3.15.11 4.8.11.4
Harmonic distortion 3.15.12 4.8.11.5
Wave shape 3.15.15 4.8.11.11
Temperature rise 3.16 4.8.11.19
Partial discharge 3.17 4.8.12
Pulse 3.18 4.8.13
Terminals not being tested 3.18.1 4.8.11.17
Electromagnetic compatibility 3.19 4.8.11.8
Overload 3.27 4.8.20
Dielectric withstanding voltage:
At reduced voltage 3.12 4.8.8.$
Induced voltage 3.13 4.8.9
Insulation resistance 3.14 4.8.10

396
°•%•° • •,-• °.,-°°°° ° .°°°-° ° -° ° ,° ,° . ° ",
- . . - - - - -, ]
TABLE H6. Qualification inspection for transformers and inductors similar
to transformers and inductors that have been qualified (cont.)
Requirement Method
Examination or test paragraph paragrapih

Corona 3.17 4.8.12

Visual and mechanical examination 3.1, 3.4 to 3.4.4.4 4.8.1.1


(external) incl., 3.5 to 3.5.2.7
incl., 3.5.3, 3.5.7,
3.32 and 3.33

4.5.3 Retention of qualification. To retain qualification, the supplier shall meet


the requirer.ents of 4.5.1 every 36 months. The qualifying activity shall be notified
in advance before action is initiated for retention of qualification. The test
samples shall be selected from items produced within a orevious 6-month production
period. However, if this production period cannot be met, the qualifying activity
shall determine which items are to be selected for qualification inspection. The
supplier shall also forward at 12 month interval. to the qualifying activity a summary
of the results of the tests performed for inspection of product for delivery, groups
A and B, indicating as a minimum the number of lots that have passed and the number
that have failed. The results of tests of all reworked lots shall be identified
and accounted for.

4.6 First article inspection. This inspection consists of meeting all of the quali-
fication tests of 4.5 through 4.5.1.3 inclusive and table H5. Procuring activities
may require contractors to furnish first article samples of these transformer or
inductor units that they propose to supply for government inspection and contractual
approval. First article approval is valid only on the contract under which it is
granted, unless extended by the government to another contract. If a supplier
desires to have his first article test data also considered for qualification, he
must notify the cognizant government agency immediately upon award of contract and
prior to the start of testing (see 6.2).

4.7 Quality conformance inspection.

4.7.1 Inspection of product for delivery. Inspection of product for delivery shall
consist of groups A and B inspections. All deliverable high voltage high power
transformers and inductors shall be subjected to Group A and B inspections

4.7.1.1 Inspection lot. Inspection shall be for completely assembled transformers


or inductors of the same grade, class, family and electrical characteristics, manu-
- factured under essentially the same conditions and having similar construction and
materials. (Similar construction and materials shall be construcd to include
differences that will not affect test results).
397

. .-..•* .:'• i . .*. *";i


.• .T -*: ".* " .- ? • :* -.- " "
::i~i• L*
:•i•--:•-;
4.7.1.2 Group A inspection. Group A inspection shall consist of the examinations
and tests specified in table H7 in the order shown.

TABLE H7. Group A inspection

Requirement Method
Examination or test paragraph paragraph

Visual and mechanical examination


(external) 3.1, 3.4 to 3.4.4.4 4.8.1.1 p..
incl., 3.5 to 3.5.2.7
incl., 3.5.3, 3.5.7,
3.11.1 to 3.11.8 incl.
3.32 and 3.33
"Seal (grades 4 and 5) 3.11 4.8.7
Dielectric withstanding voltage l 3.12 4.8.8.1 r
Partial Discharge 3.17 4.8.12
"Induced voltage 3.13 4.8.9
* Insulation resistance 3.14 4.8.10
* Electrical characteristics 2/ 3.15 4.8.11
DC resistance and resistive
unbalance 3.15.3 4.8.11.3
Inductance and inductive
unbalance 3.15.11 4.8.11.4
Turns ratio 3.15.2 4.8.11.12
Polarity 3.15.1 4.8.11.9
No load 3.15.8 4.8.11.1
l/ The Government may witness this test prior to performance of group A inspection
in which event 4.8.8.3 will apply (see 6.6).
2/ As applicable (see 3.1).
4.7.1.2.1 Group B inspection. Group B inspection shall consist of the tests
specified in table H8 in the order shown and shall be made on units which have
been subjected to and have passed the group A tests.

I.
.3.

S~398 "

. . . ..... . . . ",
TABLE H8. Group B inspection.

Test Requirement Method


paragraph paragraph
Electrical characteristics: l_ 3.15 4.8.11
Efficiency and regulation at rated load 3.15.9 4.8.11.2
Harmonic distortion 3.15.12 4.8.11.5
Electrostatic shielding 3.19 4.8.11.8.1
Magnetic shielding 3.19 4.8.11.8.2
Storage factor 3.15.14 4.8.11.10
Wave shape 3.15.15 4.8.11.11
Dielectric withstanding voltage at reduced
vwltaqe 3.12 4.8.8.3
Partial discharge 3.17 4.8.12

1/ As applicable (see 3.1). The actual circuit may be used for the
electrical inspection tests in lieu of the test circuits specified
herein.

4.7.1.2.2 Rejected lots. If an inspection article is rejected, the supplier may


rework it to correct the defects, or screen out the defective components and resub-
mit for reinspection. Resubmitted lots shall be inspected using tightened inspection.
Such articles shall be separate from new articles and shall be clearly identified
as reinspected articles.
4.7.1.2.3 Disposition of units. Units which have passed all the group B inspec-
tion may be delivered on the contract or purchase order, if the units are accepted
and are still within specified electrical tolerances, and if the terminals of the
sample units are clean and smooth.

4.7.2 Inspection of preparation for delivery. The inspection of the preservation-


packaging and interior package marking shall be in accordance with the group A and B
quality conformance inspection requirements of MIL-P-116. The inspection of the
packing and marking for shipment and storage shall be in accordance with the quality
assurance provisions of the applicable container specification and the marking
requirements of MIL-STD-129.

4.8 Methods of examination and test.

4.8.1 Visual and mechanical examination.

399
4.8.1.1 Transformers and inductors shall be examined to verify that
External.
the materials, external design and construction, physical dimensions, weight,
marking and workmanship are in accordance with the applicable requirements (see 3.1,
3.4 to 3.4.4.4 inclusive, 3.5 to 3.5.2.7 inclusive, 3.5.3, 3.5.7, 3.32 and 3.33).

4.8.1.1.1 Post-test. Transformers and inductors shall be examined to verify that the
protective coating, filling material and case construction are in accordance with
the applicable requirements (see 3.28).

4.8.1.2 Transformer and inductor inspection covers shall be removed


Internal.
to verify that the materials, internal lead wires, internal mounting, impregnating,
potting and workmanship are in accordance with the applicable requirements (see 3.1,
3.4 to 3.4.4.4 inclusive, 3.5.4, 3.5.5 and 3.5.7 and 3.33).

4.8.2 Solderability (see 3.6). Transformers and inductors shall be tested in


accordance with 4.8.2.1 or 4.8.2.2, as applicable. The method in 4.8.2.1 is pre-
ferred and shall be specified whenever practicable, otherwise the method in 4.8.2.2
shall be used.

4.8.2.1 Solder bath method. Transformers and inductors shall be tested in accordance
with method 208 of MIL-STD-202. The following details shall apply: V.-

(a) Special preparation of specimen - Sample components shall not have been
soldered during any of the previous tests.
(b) Number of terminations of each part to be tested - A minimum of two of each
type of terminal.

4.8.2.2 Soldering iron method. The test shall be performed on solder terminations,
attached to the transformer, inductor or auxiliary part thereof. The solder shall con-
form to type S, composition Sn60, of QQ-S-571. The flux shall conform to type A
or Was applicable of MIL-F-14256. The temperature of the bit shall be 3000 - 350 0 C.
The iron and solder shall be applied to the termination for 10 seconds. The solder
shall be applied for the first 2 second-. Tinning, as evidenced by the free flowing
of the solder with proper wetting of the termination, shall be completed within the
first two seconds. The transformer or inductor under test shall remain under
standard atmospheric conditions for recovery for fifteen minutes, before final
measurements are made.

400
"(a) Special preparation of specimen The surface shall be smooth and
properly tinned and the solder terminations shall not have been
soldered during any previous test.
(b) Number of terminations - in accordance with 4.8.2.1.
(c) Examinations of terminations - in accordance with method 208 of
MIL-STD-202.
(d) Soldering irons - The soldering iron shall have one of the following
bit sizes:
(1) 0.3 inch diameter, 1.25 inch exposed length reduced to a wedge
shape, over a length of approximately 0.4 inch.
(2) 0.125 inch diameter, 0.5 inch exposed length, reduced to a wedge
shape, over a length of approximately 0.2 inch.
(e) Point of application of soldering iron -1/4 inch from the nearest insulating
material or to one-half the exposed length of the terminal, whichever
point is closer to the insulating material.

4.8.3 Resistance to solvents (see 3.7). Transformers and inductors shall be tested
in accordance with method 215 of MIL-STD-202. The following details shall apply:
(a) The ,narked portion of the trapsformer and inductor shall be brushed.
(b) The number of samnple units shall be as specified in 4.5.1.1-
(c) Mechanical deformation, corrosion, or etching shall be cause for rejection.

4.8.4 Thermal shock (see 3.8). Transformers and inductors shall be tested in accor-
dance with method 107 of MIL-STD-202. The temperature for step 3 shall be the max-
imum operating temperature for the class. The following details and exceptions
shall apply:

(a) Test condition - A, 10 cycles, for qualification (group III, table H5).
(b) Test condition - A-1 (when specified) for qualification (group II,
table H5) and group A (subgroup I).
(c) After cycling - Transformers and inductors shall be examined for
evidence of leakage and other visible damage.

4.8.5 Resistance to soldering heat (see 3.9). Transformers and inductors shall be
tested in accordance with 4.8.5.1 or 4.8.5.2, as applicable. The method in 4.8.5.1
is preferred and specified whenever practical, otherwise the method in 4.8.5.2 shall
be used.

401
.*
S....*
'." S ° " ° * .• S "
. . . " " . . " " ° • ". . ° .
4.8.5.1 Solder bath methodi. Transformers and inductors shall be tested in accor-
dance with method 210 ot MIL-STD-202. The following details shall apply:

(a) Special preparation of specimen - Sample units shall not have been
soldered during any of the previous tests.
(b) Depth of immersion in the molten solder - To a point 1/4 inch from the
nearest insulating material or to one-half the exposed length of the
terminal, whichever point is closer to the insulating material.
(c) Test condition - A (350 +1_00; immersion, 3 +1/2 seconds).
-0
(d) Examination after test - The transformers and inductors shall be visually
examined and there shall be no seepage of the impregnant, loosening of
the terminals or other mechanical damage. The windings of transformers
or inductors shall be checked for continuity.

4.8.5.2 Soldering iron method. The test shall be performed on all solder termina-
tions, attached to the transformer or inductor. The solder shall conform to type S,
composition of Sn60 of QQ-S-571. The flux shall conform to type A or W as applic-
able of MIL-F-14256. The temperature of the bit shall be 300o - 350&C. The iron
and solder shall be applied to the termination for 10 seconds. The solder shall
be applied for the first 2 seconds. Tinning, as evidenced by the free flowing of
the solder with proper wetting of the termination, shall be completed within the
first two seconds. The transformer or inductor under test shall remain under
standard atmospheric conditions for recovery for fifteen minutes, before final
measurements are made.

(a) Special pre arat on of specimen - The surface shall be smooth and
properly tinned and the solder terminations shall not have .een soldered
during any previous test.
(b) Examinations after test - in accordance with 4.8.5.1.
(c) Soldering irons - The soldering iron shall have one of the following
bit sizes:

(1) 0.3 inch diameter, 1.25 inch exposed length reduced to a wedge
shape, over a length of approximately 0.4 inch.
(2) 0.125 inch diameter, 0.5 inch exposed length reduced to a wedge
shape, over a length of approximately 0.2 inch.
(d) Point of application of soldering iron - 1/4 inch from the nearest insulating
material or to one-half the exposed length of the terminal whichever point
is closer to the insulating material.

402 p
4.8.6 Terminal strength (see 3.10). Transformers and inductors shall be tested
as specified in 4.8.6.1 to 4.8.6.3.2 inclusive, as applicable. After each test,
the terminals shall be examined for loosening and rupturing and other mechanical
damage. Unless otherwise specified, all terminals on each test sample shall be
subjected to the following tests, up to a maximum of four identical terminals per
sample.

4.8.6.1 Pull.

4.8.6.1.1 Solid-wire and insulated wire lead terminals. Transformers and inductors
and auxiliary components , such as sensors and motors, shall be tested in accordance
with Method 211 of MIL-STD-202. The following details shall apply:
(a) Test condition - A.
(b) Po' ts of measurement - A force shall be applied in the direction
of the axis of termination and shall be increased gradually until
the magnitude specified in table H9 is reached and shall be main-
tained for a period of 5 to 10 seconds.

4.8.6.1.2 Solder terminals.Transformers, inductors and auxiliary components shall


be tested in accordance with method 211 of MIL-STD-202. The following details
shall apply:

(a) Test condition - A.


(b) Points of measurement A force as specified in table IX shall be
-

applied to each terminal at the point where the lead from the
external circuit connects to it. The force shall be applied in
the weakest direction of the terminal and shall be increased
gradually to the specified magnitude and shall be maintained at
that value for a period of 5 to 10 seconds.

TABLE H9. Pull.


Cross-sectional area of electrode at its
smallest point at which lead from Force
external circuit connects
Circular mils Pounds
< 2,000 ---------- --- --- --- --- 2.0
> 2,000 ---------------- ------- 5.0

403

" . I -- . . . .
4.8.6.2 Twist or be:,d.

4.8.6.2.1 Solid-wire lead terminals (other than printed circuit terminals).


Following the test specified in 4.8.6.1.1, transformers and inductors shall be tested
in accordance with method 211 of MIL-STD-202. The following detail and exception shall V
"" apply:

(a) Test condition - D.


(b) Application of torsion - The body of the component part or the
clamped terninal shall be rotated through 360 degrees about the
original axis of the bent terminal, in alternating directions, for
a total of five rotations, at the rate of approximately 3 seconds
per rotation.

4.8.6.2.2 Flat solder terminals. Any terminal that shows permanent deformation
greater than 15 degrees of the metal portion of the terminal in the terminal-pull
test specified in 4.8.6.1.2 shall be tested in accordance with method 211 of
MIL..STD-202. This test does not apply to terminals which show permanent deformation r
but are not designed to be bent 45 degrees. The following detail and exception shall
apply:

(a) Test condition - B. 0 . 6


(b) Number of bending operations - Five times through an angle
if 90 degrees (45 degrees each side of center).

4.8.6.3 Transformers and inductors shall be tested in accordance with


Torque.
. method 211 of MIL-STD-202, test condition - E. Torque for 5/16 inch, 3/8 inch and
-' ½ inch screw thread terminals shall be 40, 48 and 64 pound-inches, respectively.

4.8.7 Seal (see 3.11 and 6.15.13). Transformers and inductors shall be tested
in accordance with 4.8.7.1, 4.8.7.2, or 4.8.7.3, as applicable. Any transformer or
inductor which shows evidence of leakage may be given remedial treatment. After
completion of the treatment, the seal test shall be repeated as evidence that such
remedial treatment is adequate. All other units in the lot which have been given
similar satisfactory remedial treatment shall be acceptable.

4.8.7.1 Liquid-filled units. Transformers and inductors shall be heated in an oven


maintained at a temperature equal to or not more than 5°C greater than the sum of
the specified maximum ambient temperature and the allowable temperature rise (see 3.1
and 6.1.2), for not less than 6 hours.

"404
""
- 4.8.7.2 Gas-filled units. Transformers and inductors shall be tested in accor-
dance with method 112 of MIL-STD-202. The following details shall apply:

(a) Test condition letter - C.


(b) Leakage-rate sensitivity - 10-6 a cm33,n
/s.
(c) Procedure IV, as specified (see 3.1 and 6.1.2), test for gross
leaks as specified in 4.8.7.3.

4.8.7.3 Auxiliary components. Auxiliary components include pressure and temperature


transducers, fans, pumps and controls.

4.8.7.3.1 Transducers. Pressure-vacuum transducer and liquid temperature transducers


shall be tested at least three times during qualification. No damage to the trans-
former or sensor shall result from these tests.

* 4.8.7.3.2 Motors. Fan, pump and control motors shall be tested for electrical
continuity. Fan and pump motors shall function, without failure, during the life test.

4.8.7.3.3 Surge Arresters. Surge arresters shall be disconnected during pulse


. testing and dielectric withstanding voltage tests. Surge arresters shall be tested by
applying pulkes in accordance with IEEE STD 28-1975/ANSI C62.1-1975.

4.8.8 Dielectric withstanding voltage (see 3.12 and 6.14). Transformers and in-
ductors shall be tested in accordance with 4.8.8.1 and 4.8.8.2 when applicable.

4.8.8.1 At atmospheric pressure. Transformers and inductors shall be tested in


accordance with method 301 of MIL-STD-202. The follo !ing details and exceptions
shall apply:

(a) Magnitude of te-. voltage shall be 160% working voltage.


R() Winding-to winding - Winding to winding voltage shall
be calculated. The test voltage shall not exceed 160% peak
working voltage.
(2) Winding-to-shield/ground - The winding to shield/ground voltage
"shall be calculated.
Test voltage shail be 160% maximum calculated
voltage. Test voltages shall be applied gradually at a rate
not exceeding 500 volts rms per second.
(b) Nature of potential - AC.

405

Z• '. ,-- ... ,,, °. . , ....*-• .. .,, *. ,... . . . .. *-. . ,* .., . . ,.. , *.. , , . ,- . . . .*, . , .
(c) Duration of application of specified test voltage -60 -5
seconds for quality conformance inspection, C • seconds for
i ~~qualification inspection. •i

(d) Points of application of test voltage:


(1) Winding to case or core - Between each winding and the case or
core with all windings not under test grounded to t;;z case (if
cased) or to the normal mounting means (if uncased) and to the
core (if accessible). (See 6.18.)
(2) Between windings - The voltage shall be applied between each
winding and each of the other windings with all windings not under
test grounded to the case (if cased' or to the normal mounting
means (if uncased) and to the core (if accessible). These A-
tests need not be made if the winding-to-case or-core test
voltage of either winding under consideration is equal to, or
greater than, the winding-to-winding test voltage. The method
used to perform the between-windings dielectric-withstanding
voltage test shall consist of one source of test voltage, so
that the winding-to-winding test voltage shall be according
to (a). One terminal of the source shall be grouided to the
case (if cased), or the normal mounting means (if uncased), or
and to the core (if accessible). The test voltage applied
shall not exceed the test voltage required fo- each of the
windings to ground, and shall be applied so that the required
test voltage appears between the windings. Multiple-section
windings designed for operation only in series or parallel
shall be considered as a single winding. In no case shall the
test voltage applied between the windings exceed the sum of the
rated voltage for each of these windings to the case (if cased)
or to the normal mountijig means (if uncased), and to the core
(if accessible).
(e) The high voltage source shall have a minimum of 5 kilovolt-amperes
capacity.
(f) Examination during and after test - Transformers and inductors shall
be examined for evidence of arcing, flashover, breakdown of insulation,
and damage.

406
4.8.8.1.1 For special designs. Transformer windings internally grounded or having
any part of the winding designed for operation at or near ground potential shall be
subjected to the induced-voltage test or a combination of the dc dielectric-with-
standing voltage on the low-voltage terminal together with induced voltage, as
applicable (see 4.8.9). Windings with special dielectric features (e.g., graded
insulation) shall be subjected to the test voltage specified (see 3.1 and 6.1.2),
or to the induced-voltage test (see 4.8.9). Dielectric-withstanding voltage tests
for pulse transformers shall be as specified (see 3.1 and 6.1.2).

4.8.8.2 Altitude. Transformers and ir-ductors designed for operation Above 10,000
feet shall be tested as specified in 4.8.8.1 and in accordance with method 105 of
MIL-STD-202. The following detail and exceptions shall apply:

(a) Test condition or altitude in feet if below 30,000 feet - As specified


(see 3.1 and 6.1.2).
(b) MagnitudP of test voltage shall be 160% working voltage.
(c) Examination during and after test - Transformers and inductors shall
be examined for evidence of arcing, flashover, breakdown of insulation
and damage.

* 4.8.8.3 At reduced voltage. Transformers and inductors shall be subjected to the


dielectric-withstanding voltage tests specified in 4.8.8.1, except tha. the test
voltages shall be 125% Dercent of the working voltage and shall be apphiee for a
period of 60 seconds.

4.8.9 Transformers and inductors shall be subjected


Induced voltage (see 3.10).
to the tests specified in 4.8.9.1 through 4.8.9.3 as applicable (see 6.7). During
this test, the transformers and inductors shall be examined for evidence of continu-
ous arcing,'breakdown of insulation and abrupt changes in the input current. Means
shall be provided to indicate fluctuations of input current.

4.8.9.1 All transformers and inductors (see 3.1 and 6.1.2). Transformers and induc-
tors shall be subjected to a voltage sufficient to cause 140 percent the rated voltage
to appear across any winding. The test voltage shall be applied to any winding. .w

Windings should be grounded as they would be in service. The test frequency shall
be as selected by the manufacturer and shall be remote from any resonant frequency.
The test potential shall be applied for 7,200 +200 cycles, or 5 +1/2 seconds, which-
* .. ever is greater.

407
4.8.9.2 Pulse transformers and inductors. A test pulse voltage shall be
applied for 1 minute to any wind"-ng at the specified rated repetition rate
(see 3.1 and 6.1.2) sufficient to induce a voltage across any winding between i
25 and 50 percent of the rated pulse width, in accordance with table HIO,
and shall be performed in Jr. This test shall be repeated for units rated at greater than
10,000 volts at 125 percent rated peak voltage with the transformer or inductor terminals
Sunder oil. At thz option of the manufacturer, the test in air for transformers and r
inductors may be made at 125 percent the rated peak voltage, in which case the second
test under oil will not be required. During the test, the transformer and inductor shall be
"loadedas specified and fitted with specif".ed current protective devices (see 3.1 and 6.1.2).
The operation of any specified protective device shall not be a cause for failure.

TABLE HIO. Induced voltage for pulse


transformers and inductors

Max voltage rating )n


input voltage winding induced voltage -.

10,000 1.25 x rated voltage


10,000 to 20,000 incl 1.25 x rated voltage
20,000 to 35,500 incl 1.25 x rated voltage
v '..

4.8.9.3 Saturating core power transformers. Saturating core power transformers should
be tested at the limit of their linear characteristics, using sine wave power sources at 140
percent norrnmil opcr~ating frequency. The test voltage shall be applied to any winding
sufficient to cause 140 percent the normal peak-to-peak voltage appear across any
winding.

4.8.10 Insulation resistance (see 3.14). Transformers and inductors shall be tested in
accordance with method 302 of MIL-STD-202. The following details and exceptions shall
apply:

(a) Test condition - B for qualification inspection; and dc test potentials from 500
I
volts to 1,000 volts for quality conformance inspection. However, for quality
conformance inspection, rejection shall be based on measurements made at
500 volts.
(b) Points of measurement:
(1) Wir.'ing to case or core - The potential shall be applied between

408

. , - . * ..
L
(2) Between windings - The potential shall be applied between each
winding and all other windings connected together.

The measurements shall be made at any temperature above 20 0 C and at


ambieAt room husidity, but rejections shall be based on measurements
made at 250 -+100•C and at a relative humidity not greater than 80 percent.

4.8.11 Electricdl characteristics (see 3.15). The electrical characteristics shall


be retermined by the tests specified herein, as applicable (see 3.1, 6.1 and 6.1.2).
Electrical tests included herein do not embrace all of the electrical tests that
may be requested.

4.8.11.1 No load.
Rated voltage at the frequency or frequencies specified (see 3.1
and 6.1.2) shall be applied to the primary with the secondary or secondaries
unloaded (windings shall not float). The following shall be determined:

(a) No-load rms current (Inl).


(b) No-load power (P
(c) Primary tap and secondary rms voltages.
(d) Center-tap voltage unbalance in percent = (VI - V2 ) X 100
. V1
The voltage unbalance shall be computed: V1 and V2 are the voltages
of each part of the winding, and V1 > V2 .
4.8.11.2 Efficiency and Regulation
4.8.11.2.1 Unrectified outputs. Unrectified output secondary voltages shall be
measured with the transformer primary ex(:ited with rated voltage at the specified
frequency (see 3.1 and 6.1.2), and with -ated rms load currents flowing in the
* secondary windings.

4.8.11.2.2 Rectified outputs. Rms voltages at the seco; iary terminals shall be
measured with the transformer primary excited at rated voltage at the specified
frequency, and with rated dc current floving from a specified rectifier and filter
into a resistive load (see 3.1 and 6.1.2).

4.8.11.2.3 Efficiency, Input power and output power shall be measured with the
transformer primary excited at rated voltage at the specified frequency and with
rated currents flowing in the secondary windings. Measurements shall be taken at
½ rated output load, rated load and 1 "5 rated load at unity power factor. Efficiency
shall be calculated using the formula:

Efficiency = output (watts) input - losses = output


input (watts) input Output + losses
.. .. . .. Output..
40ý
4.8.11.2.4 Regulation, Regulation shall be determined by measurement or
calculation.

4.8.11.2.4.1 Measurement.
Secondary voltages shall be measured with the primary
Fully excited with rated voltage at the specified frequency. Primary and secondary
voltage measurements shall be taken at no load and ht rated load with unity power factor, :1
0.8 lagging power factor, and 0.9 leading power factor. Regulation shall be deter-
mined by the formula:
V V
Regulation = N - L
VN
where: VN = no load, secondary output voltage
V1 = rated load, secondary output voltage

4.8.11.2.4.2 Determination of Transformer Regulation. The regulation of a trans-


former shall be determined by calculation based on the measured values of impedance

voltage and impedance power corrected to the winding maximum operating temperature
rise. •

The exact regulation is given by:

.(r + p)' + (x + q)2 -1 for laggtng loads

V(r + p7 + (x - q -1 for leading loads


where
p = power factor of load
q = +, F_ 7

x = leakage reactance of transformer


r = dc resistance of transformer windings

The quantities p and q, x, and r are on a per unit basis so that the result is to
be multiplied by 100 to get the regulation in percent.

The approximate regulation is given by:

pr + qx + x2 2
pr - qr)2 for lagging loads
2
2
*pr - qx + (P + gr)- for leading lcads

The terms are on a per-unit basis as indicated above, and the result is to be
multiplied by 100 to express the regulation in percent.

410

* * * *. * * *
IV
This approximation gives results very close to the exact method.

A general expression for the calculation of transformer regulation which permits


calculations to any degree of precision justified by the supporting data is:
23452 5216 633 7
reg = a - ½ a + ½ a- 5/8 a + 7/8 a- a6 + .a
where
reg = regulation on a per-unit basis
a = a quantity depending upon the angle and magnitude of the transformer im-
pedance, the power factor of the load, and the number of windings in the
transformer

4.8.11.2.4.3 Two-Winding Transformers. The quantity a for use in Equation


for the calculation of the per-unit regulation of a two-winding transformer is
determined as follows:
2
a z co s( + )

where
impedance loss
r = r,•sistance factor = (in kilowatts)
rated kVA
impedance kVA
z = impedance = rated kVA

x = reactance +Ii2 r2
0 impedance angle of transformer impedanLe

cos 0 r
z
p =power factor of load =cos 9
9 =phase angle of load current
positive for leading current V

negative for lagging current

4.8.11.2.4.4 Three-Winding Transformers. Unless some simplifying assumptions are


made, it is extremely difficult to calculate the regulation of a three-winding
transformer. The following assumptions are made:,-
(1) The current in the secondary winding not being considered shall be assumed
as remaining constant even though its voltage actually does change.

4111
(2)
The phase angle of the currents in both secondaries shall be taken as
given in reference to the voltage of the secondary winding being considered.

In the calculation of the regulation of a three-winding transformer it is customary r


to utilize the equivalent impedance of each individual winding.

The mutual impedance between the secondary and tertiary windings is the same in
magnitude and phase angle as the individual equivalent impedance of the primary
winding, as determined by use of Equations in 4.8.11.2.4.2.

The regulation is calculated from the primary winding to each of the secondary
windings separately.

The quantity a for use in the Equation of 4.8.11.2.4.2 for the calculation of the
per-unit regulation of a three-winding transformer is determined as follows:

(1) For the per-unit regulation from primary to secondary, a = a1 2

2 mt2

12 12 cos mtcos (0m + t


212+9s)+2 2

+ z 1 2 mt cos (012 + 0 ms
m- 9
t

where
Z = per-unit impedance factor, primary to secondary winding, on basis of
secondary load
r
012 = impedance angle of primary to secondary impedance, zl 2

s= phase angle of secondary load current


positive for leading current
negative for lagging current
mt = per-unit mutual impedance factor, tertiary to secondary winding, on basis
of tertiary load current

Om = impedance angle
mt of mutual impedance, tertiary to secondary, mt
AQt = phase angle of tertiary load current; positive for leading current;
negative for lagging current

412

. . .
4.8.11.3 DC resistance and resistive unbalance, The dc resistance of the windings
shall be measured at or corrected to 200 C. The resistive unbalance of center-tapped
"windings in percent 11R
Rl R2 ) x 100 shall be computed.
- R1 and R are the resistances

of each part of the winding, and R, LR 2 . For resistances under 1 ohm, measure-
ments shall be made with a Kelvin bridge or equivalent.

4.8.11.4 Inductance and inductive unbalance. The inductance of the windings shall
be measured at the specified test voltage and frequency with the specified dc current
applied (see 3.1 and 6.1.2). The inductive unbalance of center-tapped windings in
percent L1 - L2 ) x 100 shall be computed. L, and L2 are inductances of each part
L1

of the winding, and L1 > L2 .

4.8.11.5 Harmonic distortion.The transformer shall be terminated in its proper


source arhd load impedance. A sine-wave voltage of specified frequency shall be
applied such that the specified output conditions are achieved and the total
harmonic distortion shall then be computed or measured (see 3.1 and 6.1.2).

4.8.11.6 Primary impedance (for qualification and first article inspection only).
Transformer primary impedance shall be measured with all normally loaded secondaries
loaded with their specified impedances, and with specified dc currents flowing in
the windings. The resistance and reactance looking into the primary shall be measured
at the specified input frequency and voltage by a bridge or equivalent method approved
by the Government (see 3.1).

4.8.11.7 Self-resonant frequency CSRF). Unless otherwise specified (see 3.1 and 6.1.2),
the self-resonant frequency shall be determined as follows, using the test circuit
shown on Figure H2. Starting at the lowest frequency within the specified frequency
range, the frequency shall be increased and the voltmeter or equivalent observed
for voltage dip. The frequency at which the minimum dip occurs shall be recorded
as the self-resonant frequency.

4.8.11.8 Electromagnetic compatibility. Electromagnetic compatibility shall be


determined by measuring the electrostatic and electromagnetic shielding effective-
ness in accordance with MIL STD 461.

413
I"-:

•IV

SIGNAL
SOURCE Es PRIMARY SECONDAR i (NO LOAD)

R 5

FigureH2: "ltasurementof.SRF

.I
",•
I I
T I
II

I I

4 SIGNAL I.DETECTOR
. . . .*:.-*
-.
. .' ;
. .". ..- . .

Figure H3. Electrostatic-shiieding Circuit

414
4.8.11.8.1 Electrostatic shielding; With all windings short-circuited and those
* •on the same side of the electrostatic shield connected together, using the circuit
shown on Figure H3, the voltage of the signal generator at the specified frequency
(see 3.1 and 6.1.2) shall be set to give a definite indication on the detector, with
switch "S" open. With switch "S" closed, the generator voltage shall be increased
so as to yield the same indication on the detector, and the ratio of the generator 2.
voltages shall be computed. The detector shall have a minimum input impedance of
1 megohm.

4.8.11.8.2 Magnetic shielding.


The transformer or inductor shall be placed in the
approximate center of a Helmholtz structure (see 6.8), consisting of two test coils
placed coaxially 1 foot apart and connected in series aiding, but at least 3 inches
from the transformer envelope. Each coil shall consist of 1,500 turns of 0.00795-
inch diameter (AWG size 32) wire, wound on a coil form having a radius of 1 foot and
a length of 1 inch. A 115-volt, 60 Hz alternating voltage shall be applied across
the series-connected coils; the transformer or inductor shall be rotated until the
voltage across the highest voltage or highest impedance winding is a maximum, and
this value shall be noted. The detector shall have a minimum impedance of 1 megohm.

4.8.11.8.3 Alternate test. The specimen under test shall be energized and the
external field shall be measured by a suitable probe.

4.8.11.9 Polarity.
With the transformer primary and secondary windings connected
in series as specified (see 3.1 and 6.1.2), and with a voltage applied to one of
the windings, comparison shall be made between the sum of the voltages across in-
dividual windings and the voltage across the series of windings. Any other suitable
method of determining polarity is permissible.

4.8.11.9.1 Alternate methods. Two alternate methods are in common use for testing
the polarity and checking the lead marking. They are: 1) inductive kick with direct
current, and 2) alternating-voltage test.

4.8.11.9.2 Polarity by Inductive Kick. Polarity of transformers with leads arranged


as in Figures H4-1 or H4-2 may be determined at the time of making the resistance
measurements as follows:
(1) With direct current passing through the high-voltage winding, connect a
high-voltage, dc voltmeter across the outlet terminals of the same windings
so as to get a small positive deflection of the pointer.

415
. - - - .. * . * . . , . .1 7.
0 0

*0

Fig. H14-1 Fig. H4-2


Subtractive Polarity Additive Polarity
Fig. 114 Leads

i Fi.

VV

A.
PT

AV0U V AV
A F

CT-
A P

Fig. H6-1 Fig. H16-2


Without Instrument Transformers With Instrument Tlransformers
Fig. li-6
Connections for the Excitation Test of a Single-
Phase Transformer
AV Average-Volt~ax Voltmeter

416
each winding and the case or core with all windings not under
test grounded to the case.
(2) Then transfer the two voltmeter leads directly across the
transformer to the adjacent low-voltage leads, respectively.
(3) The direct-current excitation is then broken, thereby inducing
a voltage in the low-voltage winding (inductive kick) which
will cause a deflection in the veltmeter.
(4) If the pointer swings in the same direction as before (positive),
the polarity is additive.
(5) If the pointer swings in a negative direction, the polarity
is subtractive.

4.8.11.9.3 Polarity by Alternating-Voltage Test. Connect the adjacent left-


hand high-voltage and low-voltage outlet leads together facing the low-voltage
side of the transformers (such as H1 and X, in Figure H5).

Apply any convenient value of alternating voltage to the full high-voltage


winding and take readings of the applied voltage and the voltage between
the right-hand adjacent high-voltage and low-voltage leads.

If the latter reading is greater than the former, the polarity is additive.

If the latter voltage reading is less than the former (indicating the approxi-
"mate difference in voltage between that of the high-voltage and low-voltage

windings), the polarity is subtractive.

This method is practically limited to transformers in which the ratio of


transformation is 30 to 1, or less, since otherwise the difference between
the two readings will not be very marked.

4.8.11.9.4 Polarity Test on Three-Phase Transformer. A phase-relationship


for three-phase units shall be determined.

417

77 . ...
4.8.11.10 Storage factor. Storage factor (Q) shall be measured under the condi-
tions specified (see 3.1 and 6.1.2).

4.8.11.11 Wave shape. With the source and load conditions as specified (see 3.1
and 6.1.2), the wave shape of the output shall be determined.

4.8.11.12 Turns ratio or voltage ratio (as specified). The ratio shall be deter-
mined by the voltmeter method or any other suitable means.

4.8.11.13 Short-circuit test (for qualification or first article inspection only).


With the secondary windings shorted in turn, the voltage applied to the primary
. shall be adjusted until the secondary is carrying rated current. The primary power
in watts shall then be measured.

4.8.11.13.1 Overload short circuit. With all secondary windings short circuited,
the voltage applied to the primary shall be adjusted until the high power secondary
winding is carrying 3 per unit rated current for 1 second. The transformer shall
not fail.
4.8.11.14 Core Loss. The core loss or excitation loss shall be determined with a
sine wave voltage, unless a different wave form is inherent in the operation of the
transformer. The average absolute voltage reading voltmeter shall be used for
correcting the measured excitation losses to a sine-wave voltage basis. The average
-voltage voltmeter method, therefore, utilizes an average-voltage indicating volt-
meter consisting of a d'Arsonval voltmeter having in series with itself a full-
wave rectifier.

Figure H6-1 shows the necessary equipment and connections when no instrument
transformers are needed; Figure H6-2, when they are needed, which is the general
case. As indicated in Figure H6-1, the voltmeter should be connected nearest to
the load, the ammeter nearest to the supDly, and the wattmeter between the two
with its potential coil on the load side of the current coil.

When transformers are used for measuring excitation losses, they shall be instrument
transformers.

418 w
Low power-factor wattmeters shall be used to obtain accurate results.

Either the high- or low-voltage winding of the transformer under test may be
used, but it is generally more convenient to make this test using the low-voltage
winding. The full winding (not merely a portion of the winding) shall be used.

Adjust the frequency to the desired value as indicated by the frequency meter,
and the voltage to the desired value by the average-voltage voltmeter. Record .
the simultaneous values of frequency, rms voltage, power, average-voltage and
current readings. Then disconnect the transformer under test and read the tare
on the wattmeter which represents the losses of the connected instruments (and
potential transformer if used), and which is to be subtracted from the earlier
wattmeter reading to obtain t::e excitation loss of the transformer under test.

The eddy-current loss in the core varies with the square of the rms value of the
excitation voltage. When the test voltage is held at rated voltage with the
average-voltage voltmeter, the actual rns value of the test voltage may not be
the rated vitlue, and the eddy-current loss in the test will be related to the
correct eddy-current loss at rated voltage by Equation lb.

The correct total excitation loss of the transformer shall be determined from
the measured value by means of equation la:
Pm
PeP +kP (Eq la)

where
P = excitation loss at voltage Ea, corrected to a sine-wave basis
Pm = excitation loss measured in test
P1 = per unit hysteresis loss, referred to Pm
P2 = per unit eddy-current loss, referred to Pm

k r (Eq 1b)

Er = test voltage measured by rms voltmeter


Ea = equivalent sine-wave voltage, rms measured by average-voltage voltmeter.

*
o . . . *°.

419
- L' -,.;
. • . .. - - ~ . -. . -. . ,. , -- • , . • • . .• • • • . .=-° - . .I

4.8.11.14.1 Excitation Loss of Three-Phase Transformers. The methods described


above for single-phase units shall apply also to three-phase units, with the
following additions and modifications:

(1) In measuring the core loss of three-phase transformers with two


wattmeters, three entirely separate sets of readings shall be taken
by using each of the three lines in succession as zhe cc.wmon line.
The average value of the three sets of readings shall be recorded as
the true no-load loss.
(2) In using the two wattmeter method the wattmeters must be read accurately.
Because of the low power factor, the reading of one wattmeter will be
negative and must be subtracted from the other. The two readings may
be of the same general order of magnitude, so that slight inaccuracies
in their values may lead to large percentage errors in their small
difference. Under such difficult conditions greater accuracy may be
obtained by the following alternative procedure.
(3) Measurements may be made with three wattmeters, each potential circuit
being connected from one line to the three-phase neutral, when available.
The three readings are added to obtain the excitation loss. -:•* •

(4) If the three-phase neutral is not available, an artifical neutral may


be derived. If potential transformers are necessary, the
open d *":-connection should be used to supply the Y-connected wattmeters.

4.8.11.15 Insulation Power Loss. The dc insulation power loss shall be calculated
using values obtained in 4.8.10 Power shall be calculated by proportioning the dc
test voltage to the rated voltage of the windings.

4.8.11.16 Bushings.
The insulation level of bushings shall be twice rated voltage.
Bushings shall be given dielectric withstanding voltage tests and impulse tests.

4.8.11.17 Terminals not being tested. Terminals and auxiliary wiring not being
tested shall be grounded or short circuited in a manner that dc:s not interfere
with the test article or generate excessive voltages within the non-tested circuit.

4.8.11.18 Altitude. Transformers and inductors housed in metal, sealed, pressurized


or liquid filled cases having coaxial shielded output leads or sealed coaxial r
shielded leads are exempt from altitude tests. - ,

420

:------------------------------"--------------------------"-----"-"-""---"
4.8.11.19 Temperature rise (see 3.16). Unless otherwise specified (see
"3.1 and 6.1.2), the temperature-rise test shall be performed on transformers
and on inductors. The temperature rise of each winding shall be based on
the change-in-resistance method and shall be computed by the following formula:

T - R-r (t + 234.5) - (T-t)

Where

T = Temperature rise (in °C) above specified maximum ambient


temperature (see 3.1 and 6.1.2),,
R = Resistance of winding (in ohms) at temperature (T + T).
r = Resistance of winding (in ohms) at temperature (t).
t = Specified initial ambient temperature (in °C).
T = Maximum ambient temperature (in °C) at time of power
shutoff. (T) shall not differ frem (t) by more than
0
5 C.

At least three potential hot spots in the transformer or inductor shall be


measured. The transformers shall be conditioned for at least 2 hours prior
to test with the normal cooling systems operating before resistance (r) is
measured. For transformers, rated voltage shall be applied to ti.j primary
with the specified loads across the secondaries (see 3.1 and 6.1.2). For
inductors, rated dc and ac current shall be applied to the windings. Trans-
formers or inductors shall be operated until two consecutive resistance readings
on the highest resistance winding are the same. If the coolant power is
required to be shut off, the resistance measurements (R) shall be made as
soon as possible. The transformers and inductors shall then be examined
for evidence of physical damage. At the option of the supplier, the test
may be performed at 60 Hz for transformers rated at 50/60 Hz provided that
the primary voltage is increased to 1.2 times the rated voltage and the second-
ary currents are maintained at rated current.

4.8.11.20 Pulse Transformer Electrical Characteristics. Waveform parameters


shell be measured as specified in 4.8.11.20.1 and 4.8.11.20.4 inclusive.

421
Unless otherwise specified (see 3.1), the network shown on figure H7 shall
be used to determine the parameters. For parameters not listed, means of
measurement shall be as specified (see 3.1). Ir

TRANSFORMWR Uf•DER TEST

Z,2

PULSE L

GENERATOR INU
C:2

.1€

Zg = Source impedance
Zs= Shunt impedance
Z= Current limit and balance impedance
ZL = Load impedance

"FigureH7: Network for Testing and Determining Waveform Parameters

"4.8.11.20.1 Pulse rise time. The method of measurement for the pulse rise
time (see figure HS) shall be as follows:

Wa) Obtain a calibrated (time and amplitude) picture of the waveform

including the pulse. Delineate the pulse by excluding those portions


of the waveform determined to be unwanted or nonpertinent.
(b) Draw the zero axis of the pulse.
(c) Find the peak pulse amplitude.

422
(d) Draw two lines parallel to the zero axis and spaced on each side
of the zero axis by 90 percent, or other specified fraction (see
3.1), of the peak pulse amplitule and two parallel lines spaced
on each side of the zero axis bf 10 percent, or other specified
fraction 'see 3.1), of the peak pulse amplitude. The time interval
between the first point of intersection of the pulse trace and
either 10 percent line and the first point of intersection of the
pulse trace and either 90 perceoit line is the pulse rise time.

-TEPLEEXCLUDED PORTION OF
\THIE WAVEFORMd
E-TH
PULSE1

Axis AI
- O- .PULSE RISE ULSE RISE ' r PULSE rISE
TIME TI'E TIME

FigureH8: Examples of Pulse-Rie-Time Determination

4.8.11.20.2 Pulse duration. The method of measurement for the pulse duration
(see figure ;!9) shall be as follows:

(a) Obtain a calibrated (time and amplitude) picture of the waveform


including the pulse. Delineate the pulse by excluding those portions -
of the waveform determined to be unwanted or nonpertinent.
\o) Draw 'he zero axis of the pulse.
(c) Find the peak pulse amplitude.
(d) Draw two lines parallel to the zero axis spaced on each side of
the zero v.:is at 50 percent, or other specified fraction (see 3.1),
of the peak pulse amplitude. The time interval between the first
and last points of intersection of the pulse trace and either line
is the pulse duration,

423
~THE
PLSE-~ EXCLUDED PORTIONi
II 1~OF THE WAVEFORM 5
ZEROZEO
AXIS -A ,I TT Iý ZEIIO
t-PULSE PULSE PULSE
DU'RATION DURATION DUATION

Figure H9. Examples of Pulse-Duration Detormination

4.8.11.20.3 Peak pulse amplitude. The method of measurement for the peak
pulse amplitude (see figure H10) shall be as follows:

(a) Obtain a calibrated (time and amplitude) picture of the waveform


including the pulse. Delineate the pulse by excluding those portions
of the waveform determined to be unwanted or nonpertinent.
* (M Draw the zero axis of the pulse.
(c) Find -:he maximum departure of the pulse trace from the zero axis
(regardless of polarity sign). This departure is the peak pulse
amplitude.F

EXCLUDED "PORTION
OF T"E VsAVEFORM
PEAk PULSE
'AWIJfTUOE

PEAK PU4.SE
ZERO ZERO~E ZERO
AXS- ~ AXIS AXIS
AMPLITUDE

Figure 1110., Examples of Peak-Pulse Amplitude Deteni~hadon

* 424
"4.8.11.20.4 Pulse decay time. The method of measurement for the pulse decay
time (see fig. H1l) shall be as follows:

(a) Obtain a calibrated (time and amplitude) picture of the waveform including
the pulse. Delineate the pulse by excluding those portions of the wave-
form determined to be unwanted or nonpertinent.
(b) Draw the zero axis of the pulse. V-
(c) Find the peak pulse amplitude.
(d) Draw two lines parallel to the zero axis spaced on each side of zero
axis by 10 percent or other specified fraction (see 3.1), of the peak
pulse amplitude. The time interval between the last point of the inter-
section of the pulse trace and0either 90 percent line and the last point
of intersection of the pulse trace and 90
either percent line is the

pulse decay time.

EXCLUDED PORTION
THE \OF THE WAVEFORM

zZERO ZERO ZERO


AXIS AXIS AXIS
PuLsE DECA, TIME • "- E ---PULSE
S'IM
.,
DECAY TIME
r- PULSE DECAY TIME

Figure HI 1: Example of Pulse-Decay. 77m Deterination

42

425 '

* .° . . .- o ......
o.
. . ° ° o °. t
4.8.12 Partial discharges (see 3.17). When specified (see 3.1 and 6.1.2),
transformers and inductors shall be tested in accordance with 4.8.12.1 or
4.8.12.2 as applicable. The detector used for this test shall have the sensi-
tivity of one picocoulomb or less and -hall have a reasonably uniform response
up to 500 kilohertz. A liquid-filled .,dt may be tested at any angle of
"inclinationunless an angle is specified (see 3.1 and 6.1.2). Partial dis.-
S..charge peak magnitudes shall not exceed the following limits when tested
at rated voltage.

Voltage Limit Counts/Minute Not to Exceed


KV PC/KV Over Limit PC/KV

DC 1 5
AC 2 10 5

4.8.12.1 Intrawinding insulation. When specified (see 3.1 and 6.1.2), transformers and
inductors shall be tested using circuit I of figure H12. The partial discharge test voltage
shall be applied under pressures equivalent to pressures ranging from. sea level to the
altitude specified (see 3.1 and 6.1.2). Partial discharge peak magnitudes shall be as
defined in 4.8.12 during a 3 minute test at normal operating voltage. High voltage S-

winding shall have a ground reference.

4.8.12.2 Interwinding insulation. When specified (see 3.1 and 6.1.2), transformers and
inductors shall be tested using circuit 2 or 3 of figure H12, as applicable. The test
voltages shall be applied under pressures equivalent to pressures ranging from sea level to
the altitude specified (see 3.1 and 6.1.2), in the same manner as specified for the
dielectric-withstanding voltage test (see 4.8.5). Partial discharges shall not exceed the
foliowing limits when tested at rated voltage.

Voltage Limit Counter/Minute Not to Exceed


KV PC/KV Over Limit PC/KV

DC 1 1 5
AC 2 10 5

426 W"

._.. o,- .
.. o. . °. . , • o . . . . .
- r * .* -;-.

ir

IuI

0
>r

00

C4 8 r

zkw. IL
_ _ _ _ _ _

LUXL

vi-

40 quDNIONLIM DANONIM

AMMd~d 05

0744
* * * .*."--- .. -,--.- . .

4.8.13 Pulse. When pulse tests between winding and core are specified (see 3.1 and 6.1.2),
there shall be no momentary or intet mittent arcing or other indication of breakdown or
fIlashover, nor shall there be any visible evidence of damage. r
4.8.13.1 Connections for Pulse Tests. In general, the tests shall be applied to each
terirninal, one at a time.

ir
4.8.13.2 Terminals Not Being Tested. Neutral terminals shall be solidly grounded except
in the case of low impedance windings. Line terminals, including those of
autotransformers and regulating transformers, shall be either solidly grounded or else 7

grounded through a resistor with ohmic value not in excess of the following values:

Nominal System
Voltage Resistance
(kV) (Ohms)

345 & below 500 r


500 400
700 300

4.8.13.3 Wave To Be Used for Pulse Tests. A nominal 1.2 x 50 microsecond wave shall be
used for pulse tests.

Positive or negative waves may be used for other than front-of-wave test, which shall be
negative.

Waves of negative polarity of oil-immersed transformers .nd of positive polarity for dry-
type or compound-filled transformers are recommended.

If in testing oil-immersed transformers the atmospheric conditions at the time ol test are
such that the bushings will not withstand the specified polarity wave, then a wave of the
opposite po!arity may be used on the particular terminal involved.

P.
The time to crest shall not exceed 2.5 microseconds except for windings with large
parasitic capacitance (low voltage, high kVA and some high voltage, high kVA windings).

4.8.13.4 VoltMe. The peak basic insulation voltage level to which the transformer or
inductor shall be tested is 200 percent peak rated voltage.

428

"• . . . . . . ~ . ~ ~.. .. *-.*,- .* ° ~


.- o- ,* - . . -.
. -*.°.- . *o,.*.Io- k-o ° ° ' , % o -°o % % o,.o -. ° - . " o . , , , . o - " - , - ---.... . .....--
4.8.14 Salt spray (corrosion) (see 3.21). When specified (see 3.1 and 6.1.2.)
Transformers or inductors shall be tested in accordance with method 101 of MIL-STD-202.
"(a) Test condition - B.
(b) Salt solution concentration - 5 percent.
"(c) Examination after exposure - Transformers and inductors shall be thoroughly
washed. The temperature shall not exceed 380 C. The transformer or inductor
shall be placed in an oven maintained at 500 +30 C for a period of 24
+4 hours. At the end of this period, the transformers and inductors
shall be removed from the oven and examined for corrosion.

4.8.15 Vibration (see 3.22). Transformers and inductors shall be tested in accor-
dance with 4.8.15.1 or 4.8.15.2, as applicable.

4.8.15.1 Vibration, low frequency. Transformers and inductors shall be tested


in accordance with method 201 of MIL-STD-202. The following details and exceptions
shall apply:
(a) Tests and measurements prior to vibration - Not applicable.
(b) Method of mounting - Transformers and inductors shall be rigidly mounted by
their normal mounting means.
SC(c) Procedure - When specified (see 3.1 and 6.1.2), transformers and inductors
shall be placed in a test chamber and preheated to the specified maximum
ambient temperature for the class (see 3.1 and 6.1.2) plus one-half the
"alle-abletemperature rise. Vibration in each plane shall begin 5 minutes
after removal from the test chamber.
(d) Apparatus - For transformers and inductors weighing more than 10 pounds,
the sequence of vibration shall be as follows: First vertically, and
then horizontally in two mutually perpendicular directions. Two machines
may be used (one vibrating horizontally and one vibrating vertically), or
a single machine may be used which provides for both vertical and horizontal
table motion, or a vertical vibrating machine, at the option of the supplier.
(e) Examinations after vibration - Transformers and inductors shall be examined
for evidence of leakaqe and physical damage.

4.8.15.2 Vibration, high frequency (when specified). Transformers and inductors


shall be tested in accordance with method 204 of MIL-STD-202. The following details
and exception shall apply:
-- (Ca) Mounting of specimens - As specified in 4.8.15.1(b).
(b) Test-condition - D, unless otherwise specified.
(c) Examinations after vibration - As specified in 4.8.15.1(e).

429
r- r r- -r . -C . . i. >. w .. ' r

4.8.16 Shock (see 3.23).


Transformers and inductors shall be tested in accor-
dance with 4.8.16.1, or when specified (see 3.1 and 6.1.2), in accordance with
4.8.16.2.
,
4.8.16.1 Specified pulse. Transformers and inductors shall be tested in accordance
with method 213 of MIL-STD-202. The following details and exceptions shall apply:
(a) Test condition - I, unless otherwise specified.
(b) Examinations after shock - Transformers and inductors shall be examined
for evidence of leakage and physical damage.

4.8.16.2 High-impact. Transformers and inductors shall be tested in accordance


with method 207 of MIL-STD-202. The following detail and exception shall apply:
(a) Mounting fixtures - Figure "Standard mounting fixtures for electrical
controller parts" of method 207.
(b) Examinations after shock - As specified in 4.8.16.1(b).

4.8.17 Winding continuity (see 3.24.) All windings of transformers and inductors
shall be tested for electrical continuity by any suitable means.

4.8.18 Immersion (see 3.25). Transformers and inductors shall be tested in


accordance with method 104 of MIL-STD-202. The following detail and exception
shall apply:

(a) Test condition - B.


(b) After final cycle - Transformers and inductors shall be washed under
running tap water and dried. After the drying period, transformers and
inductors shall be examined for evidence of leakage and other visible
damage.

4.8.19 Moisture resistance (see 3.26). Transformers and inductors shall be tested
in accordance with method 106 of MIL-STD-202. The following details and exceptions
shall apply:

(a) Mounting - On racks.


(b) Initial measurements - Not applicable.
(c) Conditioning - The 24-hour initial drying period prior to the first cycle
may be omitted.
* (d) Polarization - Unless otherwise specified (see 3.1 and 6.1.2), polarization

is applicable. The polarizing voltage shall be applied during stepc 1 to


6 inclusive, between all windings not connected directly to the core or
case, and the core or case. The polarizing voltage shall be positive
with respect to the core and the case.
.430
. .
- -..- o--

(e) Loading voltage - Not applicable.


..* (f) Final examination - Upon completion of step 6 of the final cycle, trans-
""
.* formers or inductors shall be removed from the humidity chamber and shall
be conditioned for a maximum of 8 hours at standard inspection conditions
(see 4.4). After this conditioning period, dielectric withstanding
voltage (at reduced voltage), induced voltage, and insulation resistance
shall be measured at any temperature above 20 0 C and at ambient room +l 0
humidity, but rejections shall be based on measurements made at 25 -5 C
and at a relative humidity not greater than 80 percent.
(g) Visual examination - Transformers and inductors shall be examined for
any visible damage including corrosion and obliteration of marking.

4.8.20 Overload (see 3.27). The overload test shall be performed for a period of
48 hours for qualification inspection. When transformers and inductors attain an
operating temperature of less than the maximum specified for the class during the
temperature-rise test specified in 4.8.11.19, the coolant temperature for the over-
load test shall be increased to a value that results in an
operating temperature equivalent to the maximum specified for the class (see 6.11).
The overload shall be applied as specified in 4.8.20.1 ' 220.2,
',• as applicable.
At the conclusion of the test, all transformers or in.uctor ,,f be examined for
leakage or other visible damage. Transformers or induc' )e allowed to
cool for approximately 8 hours at standard test conditiL .4)before any
additional tests are performed (see 6.9).

4.8.20.1 Maximum voltage. The rated voltage at the minimum frequency of the speci-
fied frequency range shall be applied at the rated duty cycle to the primary winding
and with rated load connected to the secondary to set the load impedances. The input
voltage shall then be raised to 110 percent of the rated voltage. When applicable,
rated dc current shall also be applied during the test.

4.8.20.2 Inductors. Inductors shall have 110 percent of all rated dc currents
and ac voltages applied at the rated duty cycle.
V-.
4.8.20.3 Saturable core devices. Saturable core devices shall be tested as required
by 4.8.20.2 except that the load required shall be adjusted to 110 percent of rated
current output.

431.. ,.
4.8.21 Flammabilit~yII (grade 5) (see 3.29). Transformers and inductors shall be

tested in accordance with method Ill of MIL-STD-202. The following details and
exception shall apply:

(a) Point of impingement of applied flame - One of the lower free corners,
so that the flame is just in contact with the transformer or inductor.
The free corners of the transformer or incuctor are those corners which
are the greatest distance from the mounting brackets. However, the
flame shall be applied so that it will impinge upon the corner or area
containing the encapsulating compount.

(b) Allowable time for burning of visible flame on specimen -3 minutes


maximum.

(c) Examinations during and after test - Transformers and inductors shall
be examined for evidence of violent burning which results in an ex-
plesive-type fire, dripping of flaming material, and visible burning
which continues beyond the allowable duration after removal of the
applied flame.

4.8.22 Life (see 3.30) (life expectancy 10,000 hours). !-L-ormers and inductors j-
shall be subjected to 5 life cycles a week for a minimum %,aeks (2,016 hours).
Four of the cycles shall consist of 20 hours during which ... the transformers and
inductors shall be operated at maximum operating temperature and duty cycle for
the class, with loading equal to or greater than rated ac and dc voltages and currents,
and 4 hours at room ambient temperature without excitation. The fifth cycle of the
week shall be 68 hours at maximum operating temperature and duty cycle for the
class with samples loaded as before and 4 hours without excitation at room ambient
temperature. The electrical test circuit shall be devised so that an open circuit
(see 3.30) or short circuit (see 3.30) during the 5 life cycles shall be detected

and the time of failure recorded. For transformers only, the test may be performed
with samples loaded back-to-back provided the above-mentioned loading requirements
are met. This test may be performed at any ambient temperaturg provided that the
maximum operating temperature for the class is held within +10 C and no drafts
or varying air velocities are present. At the option of the •upplier, the test
may be performed at 60 Hz for transformers rated at 50/60 Hz and it 400 Hz for
transformers rated at 360/400 Hz provided the primary voltage is increased to at

432 WI

"k
•.e* • *
. .. .
* . .* .... ° . . . . . .° - - - . . ,°
* .
. . ..
*:
least 1.1 times the rated voltage and the maximum operating temperature for
', the class is attained. Upon completion of cycling after a minimum of 12
weeks, transformers and inductors shall be tested for insulation resistance
(see 4.8.10), dielectric withstanding voltage (at atmospheric pressure) (see
4.8.8.1) using 75 percent of initial test voltage, induced voltage (see 4.8.9),
using a voltage sufficient to cause 1.3 times the rated voltage to appear
across any winding and partial discharges (see 4.8.12). The continuous or
peak partial discharges shall not exceed two times the magnitude of the contin-
uous and peak partial discharges measured at the start of the test. Samples
shall also be examined for evidence of physical and electrical damage (see
6.9).

4.8.23 Fungus (see 3.31). Unless certification is provided, transformers


and inductors shall be tested in accordance with method 508 of MIL-STD-810
(see 3.1 and 6.1.2).

43

433

- . i : ;: : i : .)2 "" "


5. PREPARATION FOR DELIVERY

5.1 Preservation-packaging. Preservation-packaging shall be level A or C, as


specified (see 6.1). "

5.1.1 Level A.

5.1.1.1 Cleaning. Transformers and inductors shall be cleaned in accordance with


MIL-P-1I6, process C-l. I

5.1.1.2 Drying. Transformers and inductors shall be dried in accordance with


MIL-P-116.

* 5.1.1.3 Preservative application. Preservatives shall not be used. .

"5.1.1.4 Unit packaging. Transformers and inductors shall be individually packaged


<, in accordance with the unit packaging requirements of tableHll herein and MIL-P-116
insuring compliance with the general requirements paragraph under methods of pre-
servation (unit protection) and the physical protection requirements paragraph
therein.

5.1.1.5 Intermediate packaginj. Not required. 4

5.1.2 Level C. Transformers and inductors shall be clean, dry and individually
packaged in a manner that will afford adequate protection against corrosion, deter-
"ioration and physical damage during shipment from supply source to the first receiving
activi i.

5.2 Packing. Packing shall be level A, B or C, as specified (see 6.1).

"5.2.1 Level A. The packaged transformers and inductors shall be packed in accordance .
with the level A packing requirements of table Hll Boxes conforming to PPP-B-636
"shall have all seams, corners and manufacturer's joint sealed with tape,*tw. inches
" minimum width, conforming to PPP-T-60, class 1 or PPP-T-76. The closure, water-
proofing and banding requirements for the other level A shipping contai" rs showr
in tableHll shall be in accordance with the applicable box specification. Banding
(reinforcement requirements) for all fiberboard containers (?PP-9-636 and PPP-B-640)
shall be applied in accordance with the applicable appendix usiog non-metallic or
tape banding only.

434
..............
"
-4 C!-
. . - . --- -

to u
to CM -3 a

MI
c*0.
0: v

o to

-4 04 cr$
124.~co
- 0 2,.90

CD
a
0) .5 0

10 0 $- toP4CDa w 04

j4 4)04 ) 04R! :
040 4Zci ' R.wS
-~~$ S.. CS - to0 ~*
0 - -VC~-- - 0o )

5l C-

O-co co-o.
C3 _to C0-'5

154~~
0 r
P.,i u4 C.) clSO04

iL4
in -4tC
co M to

oD _ _ _ _ _ _ __ :s
_ _ _ _ _ _

0.6 0 0,

015 Q .)-
5.2.2 Level B. The packaged transformers and inductors shall be packed as specified
in 5.2.1 except that the containers shall conform to the level B packing requirements
of table Hil. Box closure shall be in accordance with the applicable box specification.

5.2.3 Level C. The packaged transformers and inductors shall be packed in shipping
*:• . containers in a manner that will afford adequate protection against damage during
direct shipment from the supply source to the first receiving activity. These packs
shall conform to the applicable carrier rules and regulations.

:* 5.2.4 Unitized loads. Unitized loads, commensurate with the level of packing speci-
"* fied in the contract or order, shall be used whenever total quantities for shipment
to one destination equal 40 cubic feet or more. Quantities less than 40 cubic feet
need not be unitized. Unitized loads shall be uniform in size and quantities to
the greatest extent practicable,

5.2.4.1 Level A. Transformers and inductors, packed as specified in 5.2.1, shall


be unitized on pallets in conformanca with MIL-STD-147, load type I, with a fiber-
board cap (storage aid 4) positioned over the load.

. 5.2.4.2 Lbvel B. Transformers and inductors, packcj as specified in 5.2.2, shall


- .be unitized as specified in '.2.4.1 except that the fiberboards caps shall be class "
domestic.

5.2.4.3 Level C. Transformers and inductors, packed as specified in 5.2.3, shall be


* unitized with pallets and caps of the type, size and kind commonly used for the
purpose and shall conform to the applicable carrier rules and regulations.

5.3 Marking.
In addition to any speciai marking required by the contract or order
(see 6.1), each unit package, supplementary and exterior container and unitized load
shall be marked in accordance with MIL-STD-129.

5.4 General.

5.4.1 Exterior containers. Exterior containers (see 5.2.1, 5.2.2 and 5.2.3) shall
be of a minimum tare and cube consistent with the protection required and shall contain
equal quantities of identical stock numbered items to the greatest extent practicable.

5.4.2 U.S. Air Force requirements. For U.S. Air Force requirements submethods IC3 and IC-2
with supplementary container conforming to PPP-B-636, class weather resistant,
.:." special requirements shall be used in lieu of submethods IA-8 and IA-14, respectively
(see table H-11).

436
-:7-
Ir
6. AOTES

* . 6.1 ;)rderi~ic jata.

6.1.1 For transformers and inductors covered by coordinated specification sheets.


*" Procurement documents should specify the following:

(a) Title, number and date of this specification.


(b) Title, number and date of the applicable specification sheet, and the
complete military part number (see 1.2.1 and 3.1).
(c) Whether hardware is required for screw terminals (see 3.5.2.6).
(d) Levels of preservation-packaging and packing required (see 5.1 and 5.2).
Method of preservation, if other than submethods IA-8 and IA-14 (see
table H-1l).
(e) Special may-king, if required (see 5.3).

6.1.2 For transformers and inductors not covered by specification sheets- Pro-
curement documents should specify the following:

(a) Title, number and date of this specification.


___(b) Type designation (minus the identification numaber) covering the grade,
class, family and eihvelope and mounting dimensions (see 1.2 to 1.2.1.5,
inclusive).
(c) Applicable drawings covering envelope, mounting and other physical dimen-
sions (see 1.2.1.5).
(d) When first article inspection is performed (see 3.3), the following is
"required:

(1) The laboratory at which first article inspection is to be performed.


(2) Sample, submission of data, and inspection routine, if other than
that specified (see 3.3 and 6.3).
(e) Type of terminal (see 3.5.2). Whether hardware i- -equired for screw
terminals and detail requirements of screw terminals (see 3.5.2.6).
(f) Whether the core is to be grounded to the case or accessible electrically
(see 3.5.5).
(g) Whether a paint finish is required and if it is to be applied to mounting
surface (see 3.5.6).
(h) Electrical characteristics and tolerances (see 3.15).

437
(i) Whether the partial discharge test is required (see 3.17), and if
so:
(1) The acceptable level of partial discharges (see 3.17).
(2) Required test circuit of figure H12 (see 4.8.12.1, 4.8.12.2,
and figure H12).
(j) Maximum ambient tomperature and maximum allowable temperature rise
(see 1.2.1.3, 3.16 and 4.8.11.19).
(k) Marking (see 3.32).
(1) Additional information for marking of individual families
(see 3.32.1 to 3.32.2, inclusive).
(2) Terminal identification if other than by numbering (see 3.32.4).
(1) Rated voltages, loads and tolerances (see 4.4.2).
(m) Applicable electrical characteristics (see 4.8.11 to 4.8.11.19,
inclusive).
(n) Whether alternate seal test is required (see 4.8.7).
(o) Dielectric-withstanding test voltages for the following:
(1) Windings with special dielectric features (see 4.8.8.1.1).
(2) Pulse transformers (see 4.8.8.1.1).
(p) Whether- zielectric-withstanding-voltage test at reduced barometric
pressure is applicable and test condition (see 4.8.8.2).
(q) Induced voltage:
Frequency range for all transformers and inductors except saturating
core power (see 4.8.9.1).
(r) Fungus (see 4.8.23).
(s) Temperature rise (see 4.8.11.19).
(t) Vibration test (see 4.8.15).
(1) Whether 4.8.15.1 or 4.8.15.2 is applicable.
(2) If 4.8.15.2 is applicable, the test condition shall be specified
if other than D.
(3) During vibration test, whether transformers and inductors
are to be preheated in a test chamber to the specified maximum
ambient temperature for the class plus one-half the allowable
temperature rise (see 4.8.15.1).

438
(u) Shock test (see 4.8.16).

"~ (1) The test condition shall be specified if other than I.


(2) Whether high-impact is applicable (see 4.8.16.2). F

(v) Whether polarization is not applicable during moisture resistance test


(see 4.8.19).
(w) Levels of preservation-packaging and packing required (see 5.1 and 5.2).
Method of preservation, if other than submethod IA-8 and IA-14 (see
table Hll).
(x) Special marking if required.
(y) Whether salt spray test is required (see 3.18).

6.2 Qualification. With respect to products requiring qualification, awards will


be made only for products which are at the time set for opening of bids, qualified
for inclusion in the applicable qualified products list, whether or not such
products have actually been so listed by that date. The attention of the suppliers
is called to this requirement, and manufacturers are urged to arrange to have the
products that they propose to offer tc the Federal Government tested for qualification
in order that they may be eligible to be awarded contracts or orders for the pro-
ducts covered by this specification. Information pertaining to qualification of
products may be obtained from the Defense Electronics Supply Center (DESC-E),
Dayton, Ohio 45444 (see 3.2).

6.3 First article inspection. Information pertaining to first article inspection


of products covered by this specification should be obtained from the procuring
activity for the specific contracts involved (see 3.3).

6.4 Assignment of type designation. Complete type designations, including the


identification number (see 1.2.1.6), will be assigned by the cognizant government
procurement agency, upon request of the Army, the Navy, or the Air Force, only
when a coordinated specification sheet has been established (see 4.5.1).

6.5 Envelope and mounting dimensions. Equipment designers should give first con-
sideration to using standard case configurations.

439
...
6.6 Dielectric withstanding voltage. Users of transformers and inductors
should note that the units have been previously tested at 100 percent dielec-
* tric withstanding voltages at least one or more times and, therefore, should
be tested only at 75 percent test voltage during subsequent inspectins such
as during incoming inspection by a purchaser. For units with a working voltage
in excess of 10 kV, partial discharge measurements at rated voltage should
be considered in additin to dielectric withstanding voltage.

6.7 Induced voltage test for inductors. Fo inductors, the test voltage
is applied directly across the coil.

6.8 Magnetic shielding. The approximate magnetic field strength for the
Helmholtz structure described in 4.8.11.8 and illustrated on Figure H13 is
43.6 oersteds per peak ampere.

ROTATE FOR MAX VOLTAGE

12" TRANSFORMER TO SE
CENTEREDT":

ar*

DIA

EACH COIL CONSISTS OF


q 1500 TURNS OF 000795
DIA. (AWG SIZE 32) WIRE"

Figure H13: Helmholtz Structure for Magnetic Shielding

440
.1
6.9 Overload and life tests (method of mounting). The same method of mlvovtiýx
- may be used for the overload and life tests.

6.10 Notes for airborne application.

6.10.1 Laminated phenolics. It is recommended that laminated phenolics not be used


in locations where they would be exposed to heavy electric discharges during normal
operations or under faulty conditions, because of the flammable conditions that
might occur.

6.10.2 Transformer and inductor sizes. Manufacturers should strive to provide


the smallest and lightest transformers and inductors.

6.11 Ambient temperature increase. Ambient temperature increase for use under
4.8.20 will be derived on an assumed linear extrapolation. For example, a class R
unit operated under 4.8.11.19 at an ambient temperature of 70°C with a 20&C temperature
rise would be operated under 4.8.20 at an ambient temperature of 85°C (105 0 C - 200 C
= 85 0 C), The normal cooling systems shall be active during the tests.

6.12 Test circuits for electrical characteristics. The actual circuit may be used
Sfor group B electrical inspection testing in lieu of the test circuits specified
herein (see 4.8.11).

6.13 Reductiun of dielectric-withstanding-voltage testing. When the dielectric-


withstanding-voltage potential required between windings is greater than that required
between windings and ground, and where there is sufficient insulation used in the
construction of the transformer or inductor, a reduction of testing may be accomplished
by specifying a sufficiently high winding-to-ground potential so that it includes the
required test potential between windings.

6.14 Notes regarding general applications for equipment designers. The equipment
designer, by proper application of the iriformation contained in the following para-
graphs, can communicate to the transformer or inductor designer of the supplier a
more complete understanding of his requirements and thus realize better equipment
reliability. This will also prevent the costly over-specification of requirements
not needed for the inatended use.

6.14.1 Specification sheet transformers and inductors. For any transformer or


* *-* inductor requirement, the specification sheets listed in supplement I should first
be reviewed and if usable for the requirement, should be specified.

441

s .**.. *-..
. .,..' ....- . .. • .. .. . . - . . • .. . .. . . . . . . . .. . . .. . . . . . . .
6.14.2 Temperature. The class designation in table H-2refers solely to maximum
operating temperature and has no relation to types of insulation material. Any in- :. *
sulation material may be used in any class of transformer or inductor, depending
entirely upon the maximum operating temperature and its associated life expectancy.
The maximum operating temperature refers to the maximum ambient temperature specified
for equipment operation plus the internal temperature rise at the time that thermal
stability is reached. It should be noted that where the total of the specified maxi-
mum ambient temperature and the specified allowable temperature rise exceeds, by any
amount, the maximum operating temperature for any given class, the unit must be
described by the letter designating the next nigher class designation and meet the
requirements thereof.

6.14.2.1 Maximum operating temperature.


The maximum operating temperature is the
same as the allowable temperature rise plus the maximum ambient temperature for the
class. Accordingly, temperature rise is the allowable te,nperature differential
between the ambient and maximum operating temperature for a given insulation for a
spec 4 fied life. For example, class R has a maximum operating temperature designation
of 105OC; this 0
is normally a 65~0 C ambient plus a 40&C rise. If the temperature rise
was determined to be 300 C, this same transformer could operate in an ambient as high
as 750C (750 C + 300 C = 105 0 C). The transformer cooling system shall be active. "*•
-

6.14.2.2 Temperature rise. Temperature rise is normally measured and rated at sea
level. At higher altitudes, the temperature rise will increase and should be
compensated for in the equipment design with cooling system considered.

6.14.2.3 Ambient temperature. It is not recommended that a higher operating ambient


temperature be specified than that to which the transformer or inductor will actually
be exposed. To do so will result in a larger and heavier unit than is needed. In
the absence of a specified ambient temperature in the individual document, the
following ambient temperatures may be used for the temperature rise test; class Q
(65°C), class R (65 0 C), and class S (85°C).

6.14.3 Envelope and mounting dimensions. Equipment designers should give first
consideration to using the various standard case sizes (or envelope and mounting
dimensions). The use of standard cases results in lower costs and faster
delivery, since these cases are generally immediately available from case suppliers'
stock and are based on the use of standard laminations.
However, when size is important, it is often necessary to utilize special cores,
core materials, and improved types of insulation, with resultant higher costs and
delayed deliveries.
442

"............."
• ° .•%••.• . . -.
.'

.. . *•
."..
..
'-- ."..°
.
. .. •. •.. " •. . * . *'. * * . '•, " .' - -, ." -. • _• . , . - ." . .
6.14.3.1 Overspecified characteristics which affect case size. The unrealistic over
specification of certain characteristics can result in a much larger transformer
-" than should be required. For this reason, do not specify:

(a) Greater than actual power requirement.


(b) Lower frequency than actual requirement.
(c) Lower dc resistance than actual requirement.
(d) Higher dc current than actual requirement.
(e) Higher than actual ambient temperature or higher temperature class.
(f) Higher than actual working voltage (including voltage peaKs).
(g) Better regulation (lower percent) than actual requirement.
(h) Excessive life expectancy.

6.14.4 Working voltage.


The working voltage marked on the transformer or inductor
represents the maximum voltage stress that may appear, under normal rated operation,
across the insulation being considered. This voltage is based on the circuitry with
w" :h the unit is associated. The working voltage marking enables personnel testing
* the units to determine the correct dielectric withstanding test voltages to be applied.

CAUTION: DO NOT USE TEST VOLTAGES AS THE OPERATING WORKING


- .VOLTAGES OF THE TRANSFORMER OR INDUCTOR.

6.14.5 Overload. Transformers and inductors designed in acccrdance with this speci-
fication are capable of withstanding an overload of 10 percent for the transformer
duty cycle.

6.14.6 Altitude rating. The altitude rating marked on the transformer or inductor
indicates that the associated working voltages are based on a pressure equivalent
to this altitude. However, the units can still be operated at higher altitudes if
the working voltages are properly derated.

6.14.7 Marking. Detailed marking requirements are indicated in 3.32.1 to 3.32.4


inclusive. Where conditions are such that less information is required or desired,
such information must be clearly specified in the procurement document.

6.14.8 Environmental characteristics. Care should be exercised in specifying


environmental test requirements to insure that the unit should be tested in a manner
compatible with the environment actually present. Thus, for example, if the end
equipment is to be shock mounted, sealed, or will include cooling facilities,
the transformer or inductor may ancounter a less stringent environment. However, it
should be noted that the effect on a transformer or inductor of the conditions to

443
which an equipment is subjected, because of position or method of mounting,
may be entirely different from the effect on the end equipment as a whole.

6.14.9 Electrical characteristics.Only those characteristics and tolerances


which are pertinent to the particular design should be specified. Normally
pertinent paragraph--. (.l. the listed characteristics may not be applicable
to each design; also, the listed characteristics do not embrace all of the
characteristics which may be applicable.)

6.14.9.1 General. Where possible, the associated circuitry should be shown


for reference, indicating tube types, and other important component parts,
in order to aid in obtaining optimum design.

6.14.9.2 Power transformers.

(a) Nominal primary voltage and possible variation. (Taps on winding


are to be clearly defined.)
(b) Operating frequency range.
(c) Secondary rms load voltages with allowable tolerance at nominal
input voltage and rated loads.
(d) Secondary rated rms and dc-Ioad currente and possible variations.
(e) Allowable regulation - The basis for regulation should be clearly
stated, e.g., 5 percent to 100 percent load, over temperature range,
etc.

(f) Electrostatic shielding in accordance with 4.8.11.8, including


the minimum ratio of attenuation.
(g) Polarity of windings.
(h) Pulse conditions and transient peaks.
(i) Partial Discharge limits should never be specified unless absolutely
necessary.
(j) Capacitive or inductive input should be specified if used in a recti-
fier or filter circuit.
(k) Efficiency at full load.

444
- - .,
I-

6.14.9.3 inductors.
°°(

(a) Rated inductance and required limits at nominal rms voltage and
frequency, and dc durrent.
(b) Allowable dc resistance.
(c) Storage factor (Q) at the specified voltage and frequency.

6.14.9.4 Saturating core power transformers.

(a) Test circuit for intended use.


(b) Drive transistors.
(c) DC source voltage and range of variation.
(d) Output load currents.
(e) Design frequency.
(f) Allowable regulation - the basis for regulation should be clearly
stated, e.g., 5 to 100 percent load over temperature range, etc.
(g) Polarity of windings.
(h) Filter input circuit if used in rectifier application.
H() Rise and fall times, maximum overshoot, etc., if applicable.

6.14.10 Resistance to solvents. If resistance to solvents test is not per-


formed, the manufacturer shall certify that the intended use of the transformer
or inductor is not fý- printed circuit application.

6.14.11 Seal.
Where doubt exists to the adequacy of the seal, due to emission
of bubbles, an insulation resistance across the seal shall be performed and
if less than 10,000 megohms, additional tests shall be performed.
p.7

6.15 Center-tapped secondary. A center-tapped secondary is described by the


winding end-to-end voltage with a tape at the mid-point.

6.15.1 Center-tapped secondary supplying unrectified loads. The current refers -

to the rms current flowing from end-to-end of the winding. Unless otherwise
specified, the center-tap lead does not carry the load current (see figure '''4).

445
FigureH14: Center-Tapped Secondary Supplying Unrectified Loads

6.15.2 Center-tapped secondary supplying rectified loads. The winding current


is the rms equivah-nt of the dc load current. The rms current is dependent
upon the type of filter used with the rectifier. The type of filter and
the dc load current must be specified. (EXAMPLE: Capacitive input filter,
100 mA dc load.) Unless otherwise specified, the center-tap lead carries
the full dc load current (see figure H15).

CAPACITIVE
•iNPUT FILTER"-

Figumr H15: Center-TappedSecndary Supplying Rectifled Loads

•44
6.16 Dielectric withstanding voltage (at atmospheric pressure) (points of
application of test voltage, winding to case or core. Grade 8 units (when
applicable) shall be wrapped lightly with metal foil on as many surfaces
as practicable in lieu of the metal case.

6.17 International standardization agreement. Certait, provisions of this


specification are the subject of international standardization agreement
(NEPR No. 20). When amendment, revision, or cancellation of this specificaton
is proposed which will affect or violate the international agreement concerned,
the preparing activity will take appropriate reconciliation action through
international standardization channels including departmental standardization
offices, if required.

6.18 Pulse Transformer Waveform definitions.

6.18.1 Pulse rise time (see 4.8.11.20.3). Pulse rise time is the interval
between the instants at which the instantaneous amplitude first reaches speci-
fied lower and upper limits; namely 10 percent and 90 percent of the peak
pulse amplitude.

6.18.2 Pulse duration (see 4.8.11.20.2). Pulse duration is the time interval
between the first and last instants at which the instantaneous amplitude
reaches 50 percent of the peak pulse amplitude.

6.13.3 Peak pulse amplitude (see 4.8.11,20.3). Peak pulse amplitude is the
maximum absolute peak value of the pulse, excluding those portions considered
to be unwanted or nonpertinent, such as spikes (see 3.1).

NOTE:
t Where such exclusions are made, it is desirable that the amplitude chose;,
illustrated
i pictorially. One method of determining the peak pulse
° itude is shown on figure H16. In this case, it is determined by
.intersection of a line tangent to the leading edge of the pulse
and a line tangent to the "flat top" of the pulse.

447
6.18.4 Pulse decý.y time (see 4.8.11.20.4). The pulse decay time (sometiw.es
referred to as the fall time) is the interval between the ir '4nts at which
the instantaneous amplitude last reaches 90 percent, and next reaches 10
percent of the peak pulse amplitude.

6.18.5 Crest pulse amplitude. The crest pulse amplitude is the maximum
value of the pulse relative to the zero amplitude level (see figure H16).

6.18.6 Leading edge. The leading edge is that portion of the pulse in which
the amplitude rijes from zero to its crest pulse amplitude 'see figure H16).

6.18.7 Trailing edge. The trailing edge is that portion of the pulse in
which the amplitude descends from its value at the end of the pulse top to
its ultimate zero level (see figure H16).
r

NJLSE WAVEFORM

LEADING -b- PUS


~-a-TRAILING EDGE-
I
.

EDGE 'Top

ICREST PULSE

"CR "UDE PULSE TOP

AMPLITUDE
jE-J MPLIUD.E.--
ZDROO

| TIM~~~~E -SEl~(O(A TM

E" PEAK PUL,,RSE AMPLITE

Hf6: Pulse Waveform

:•,.•E PEAK PULS AMPLITUDE....

A. . . ". .a" , H
- 16:• Pu s - . .. .. -l. . ..
Tr8 44
6.18.8 Pulse top. Unless otherwise specified (see 3.1), the pulse top shall
* be the flat part of the pulse shown on figure H16.
I
6.18.9 Droop. Unless otherwise specified (see 3.1), droop is that displace-
ment oi the peak pulse amplitude shown on figure H16. Droop is expressed
in volts or as a percentage of the peak pulse.

6.18.10 Overshoot. Overshoot is the amount by which the crest pulse amplitude
exceeds the peak pulse ýmplitude (see figure HI16). Overshoot is expressed
in volts or as a percentage of the peak pulse amplitude.

6.18.11 Backswing. Backswing is that portion of the trailing edge extending


below the zero amplitude level (see figure H16). Backswing may be expressed
in volts or as a percentage of the peak pulse amplitude.

6.18.12 Return backswing. Return backswing is that portion of the trailing


edge which has a polarity reversed to that of the backswing, and occurs later :.-
in time tnan the backswing (see figure H16).

6.18.13 Recovery time. Recovery time is that time interval between the
time the trailing edge of the pulse first cross-, a line representing 10
percent of the peak pulse amplitude and the last time the pulse shape crosses
either a positive or negative line corresponding to 10 percent of the peak
pulse amplitude (see figure H16).

o4 4

449
- ;-,.--.i--...-.-- - - * - - -

I.

SUBMISSION FOR QUALIFICATION INSPECTION

10. SCOPE
10.1 This paragraph details the procedures for submission of samples, with re-
quired data, for qualification testing and approval of transformers and induc-
tors covered by this specification.
20. SUBMISSION
20.1 Qualification of transformers and inductors based on complete testing
(part I of QPL-27).
20.1.1 Identification data required.

(a) Type designation of the transformer or inductor described on a


specification sheet. (Transformers or inductors covered by exist-
ing specification sheets.)
(b) For transformers or inductors that are comparable with an item
covered by an existing specification sheet and the requirements of
which c:.n be added to the sheet, the information of FigureHIl shall
be submitted. For transformers or inductors that cannot be added
to an existing specification sheet, a complete specification sheet
shall be submitted, encompssing the information required by Figure
Hll The specification sheet shall be in the format of existing spe-
cification sheets and shall be suitable for reproduction by the
photo-offset method.
20.1.2 Sample. A sample consisting of one transformer or inductor for which
qualification is sought shall be subjected to the te:.Ls of Table H5
20.2 Qualification of transformers and inductors based on similarity (Part II
of QPL- 27 ). Only transformers or inductors which have passed the complete tests
of TableH5 shall be used as basis for comparison for qualification based on simi-
larity.
20.2.1 Similar transformers or inductors. A similar transformer or inductor is
defined as a transformer or inductor which when compared to a specific qualified
transformer or inductor meets the following criteria:

450
(a) Same or lower class.
"(b) Same type of external and internal mountings; similar shape; same
type of case construction; nominal wall thickness within 25 percent
when a case is used.
(c) Linear envelope dimensions not greater than 150 percent nor less
than 70 percent of the corresponding dimensions; total volume of
envelope not greater than 250 percent.
(d) To be used at same or lower operating voltages, and same or lower
dielectric stress per mil of same insulation. :1
(e) Same or greater wire size (cross sectional area) and same wire
coating material for corresponding windings.
1/ (f) Same processing material for case, finish, marking.
(g) Same processing material for potting, insulation, impregnating and
filling.
(h) Same grade.
(i) to be used at same or lower altitudes.
(j) Same terminal construction and material including insulating and
gasketing parts; same or lower terminal strength requirements for
same size terminals.
(k) Same shock and vbration requirements.
I/ This criteria may be compared to any qualified transformer or inductor on
Part I of QPL-27.
20.2.2 Identification data required. The data required shall be in accordance
with 20.1.1(b) and that required by FigureHl2shall also be submitted.
20.2.3 Sample. All units of each type for which qualification is sought shall
be subjected to the inspection specified in Table H6.

Identification data (to be completed by manufacturer):

1. Name of Manufacturer:
2. Address of Manufacturer:
3. Manufacturer's part number:
4. Federal supply code assigned to Manufacturer:
5. Date of entries completed:

451
Instructions for use of this form:

Enter all information, including numerical values as required by this form, using
as your guide applicable military specification or standard scope, requirement,
""
. and methods of examination and test paragraphs. Military specification sheets, if
any, to which the transformer or inductor can be added:
MIL--- . (enter slash number)
This item cannot be added to any existing specification sheet
Type designation-(see MIL-_- , 1.2.1 thru 1.2.1.6) TF_____________
enter symbols.7
Federal Stock Number (FSN) (check applicable block):

Existing FSN assigned to this transformer or inductor is -


(enter numerals)
No FSN is presently assigned to this transformer or inductor.

Application of transformer or inductor:


1. Military equipment identification (Joint Electronics Type Designa-
tion System):
(enter identification no.)
2. Military documents (check all applicable blocks and enter information
requested):
"Technical Order (T.O.) - __etfcai __n.

* _TTi..tification no.)
Technical Manual (T.M.)_
(identification no.)
Military drawing
(identification no.)

452

:.. . .:. -. ; -. • _: ,... . . . . • . _ • . _. .. . . ..


• . . . " ,. .. . . . . .
FIGURE H-12 Transformer or inductor data sheet

In the space below, provide outline drawings in as many views as are required to
o °*:. show all of the principal exterior features of this transformer or inductor inclu-
ding case, mounting and terminal dimensions 1/ and tolerances 2/, and terminal
identification.

l!/ Dimensions shall be given in decimal fractions, accurate to three decImal


places.
2/ State dimensions as nominal value, with tolerances:

Examples: 1.750 + O.OOU 2.50 +0.016.

REQUIREMENTS:

Case.
Material (check applicable block): Metal

Other.
(specify material)

Nominal weight: grams, pounds.


(enter value) (cross out one)

Terminals.

Material:
(specify)

Type (check applicable block): Insulated wire leads.


Solder Terminal. Pin for printed circuits.
Screw Thread Pin for electron tube sockets
Solid wire lead other than Special:
printed zircuit. (specify type)

463
Soiderability (see 4.8.2).

Check applicable block:


4.8.2.1 4.8.2.2

Resistance to solvents (see 4.8.3). method 215, MIL-STD-202.

Check applicable block:

Applicable Not Applicable

Thermal shock (see 4.8.4).

Check applicable block:


10 cycles
25 cycles
other, specify number of cycles_ __
Resistance to soldering heat (see 4.8.5).

Bath (4.8.5.1) Iron (4.8.5.2)

Terminal strength (see 4.8.3), method 211, MIL-STD-202.


Check applicable blocks:

Equivalent diameter at cross section as defined in Table X


inches. .-
enter value) a n
Condition A (pull), applied force (in accordance with
Table IX):
2.0 pounds pounds

Condition B (bend
Condition D (twist)

Condition E (torque)
Screw-thread terminals:

Torque: pound-inches
(enter value)

FIGURE H12 Transforri' 454 r inductor data sheet - Continued

-5. ° .. .. o.-. . -......-.. ° . . . ° - .- S S S .


Other non-wire, rigid type terminals, if equivalent

diameter is greater than 1/1 inch:


Torque: ounce-inches:
(enter value)

Seal (see 4.8.7)

Check applic•>. block:

Liquid Gas Other


4.8.7.1 4.8.7.2 4.8.7.3

Dielectric withstanding voltage test.

Check applicable blocks:


At atmospheric pressure (see 4.8.8.1), method 301, MIL-STD-202:
Magnitude of test voltage: volts, rms.
Terminal identification for applicable test voltage,

At barometric pressure (see 4.8.8.2). In accordance with 4.8.8.1


and method 105, MIL-STD-202, test condition.

(specify condition lette-r).


Magnitude of test voltage:_ volts, rms.
(enter value)T-

Induced voltage (see 4.8.9).

Check applicable block:

4.8.9.1 4.8.9.2
Insulation resistance (see 4.8.10), method 302, MIL-STD-202, test condition B.

Dc test potential: volts.


(enter value)-

FIGURE H12 Transformer or inductor data sheet - Continued

. . .
455
..- .•,-.-- .,.
• . . .1": 11
1..... :".: .,. •.-
11:::"'
:.:z . ': ':..:. .•.: . . . ......
.. . "- ..•,. . ."...7 ..•..
. ..... . . ....
,..., ,.. - :' i? : , • .
Electrical characteristics and tolerances (see 4.8.11 to 4.8.11.19).
No Load___
Rated Load
Dc resistance and resistive unbalance
Inductance and inductive unbalance
Harmonic distortion
Primary impedance
Temperature rise
Efficiency_
Regulation
Core loss
Self-resonant frequency_
Insulation Power Loss
Electrostatic shielding _ _ _ _ _ _ _
Magnetic shielding
Center-tap balance at low levels
Polarity_
Storage factor
Wave shape
Turns ratio or voltage ratio
Bushings
Short Circuit Test
Impulse
Partial discharge:
Dielectric Withstanding Voltage
Frequency_
Working Voltage____

FIGUREHM2 Transformer or inductor data sheet - Continued


'456
"Power level .,.,

""" Primary winding:

Voltage ",__

Current _,__ -.
VA ___

Impedance

Secondary winding(s):

Number

Voltage, each

Current, each __

Pulse electrical characteristics

Other electrical characteristics

Pulse Transformers (waveform parameters) (see MIL-T-21038, 4.7.10)

Turns ratio

Pulse duration

Pulse rise time

Overshoot _'--

Droop _ :___

Backswing "____

Decay time __._.

Inductance uh, Not applicable L,


Impedance:

Output ,_._
*',•
. Input ---

.
457...
Pulse repetition frequency •-'-

Capacitance (winding to winding) "

Primary winding:

Pulse voltage

Pulse current

DCR o Not applicable El


Secondary winding(s):

Number __

Pulse voltage, each _ _ _

Pulse current, each _-_

DCR _, Not applicable j.


Temperature rise (see 4.8.11.19)

Specify values:
Not applicable (when the transformer is rated at

0.8 watt average output or less, and for inductors where

the product of the d-c resistance and the square of the

rated current is 0.2 watt or less.

Methods 1 II II I
Temperature rise: degrees C

"Ambient temperature degrees C

Maximum operating temperature degrees C

Partial discharges (see MIL-T-27, 4.8.12)

Check applicable block:


Required test circuit of figure 10

1 .2 3

458

"•
° "-. '. •"o.w
" ° "". " -• """"-o% . ° •' •°• ".. ".-- -. ". "" . °. " , ••" "
5.

Vibration (see 4.8.15).


"Check applicable block:
Low frequency (see 4.8.15.1), method 201, MIL-STD-202.

High frequency (4.8.15.2), method 204, MIL-STD-202.

Shock (see 4.8.16).


Check applicable block:

Specified pulse (see 4.8.16.1), method 213, MIL-STD-202,


test condition: I _ or specify condition letter

High impact (see 4.8.16.2), method 207, MIL-STO-202


Moisture resistance (see 4.8.19), method 106, MIL-STD-202

Chek.cPol arizing
applicable block:
voltage:
Applicable Not applicable

Overload (see 4.8.20)

Check applicable block:


or
Applicable Not applicable

Flammability (see 4.8.21), method 111, MIL-STD-6202.

Check applicable block:


Applicable Not applicable

Life (see 4.8.22).


Check applicable block:

Loaded Not loaded

Fungus (see 4.8.23), method 508, MIL-STD-810

Check applicable block:


Applicable. Certification

FIGURE H12 Transformer or inductor data sheet - Continued

459 V
Salt spray (see 4.8.14).
Check block if salt spray is applicable :_:
FIGURE H12 Transformer or inductor data sheet - Continued.

4..0
Ir

S-'i

!.............
DATA SHEET FOR
POWER TRAMSFORMIER :-'

EUCTRIrICL RATING

Primary (1-2): _VA, Vrms, Hz


3eo, .dary (3-4): MVrs, Arms
(5.6) Vrms, oArms
(etc)
outy cycle:

torkini voltage: (Primary) (Secondary)


Altitude:
Operating tewerature range:

PHYSICAL CHARACTERISTICS

Case size:
Weight: (In grams, oz(s) or pound(s))
Terminal type:
Terminal height:
ELEC1'UCAL PROPERTIES

Dielectric withstanding voltage (each winding):


At sea level - volts rms
At reduced barometric pressure - volts rms
No loed (see 4.8.11.1): With (vrimary voltage) volts and (frequency)Hx in (1-2):
Current in (i-_2): ma xa
Power in (1-2): watts Max
Voltage across (3:4): volts +
Voltage across (S-6): volts * -
Voltage across (etc): volts *
Rated loud (see 4.8.11.2): With primary volts 6 Hz across (l-2:--
Voltage azross (3-4): volts *
Voltage across (5-6): volts -
Voltage across (etc): - volts Z-
Electrostatic shielding: Voltage ratio: -- to _ at Bit-_i.
DC resistaico: (1-2)
(3-4)
(S-6)
Polarity: Additive, with terminals and connected.
amperature rise: *C with _ __voTIs ins, Hz
across (1-2) at an sebient temperature of 6C.

(In the space below, provide circuit diagram)

S--

461

7!-.
". . . . . .- + + -
DATA SHEET FOR
POWR IMuCI=C

ELECTRICAL .RATIN.G

"Inductance: h imn
Current: amp. dc
Voltage: volts rus
Frequency: _ __ z
DC resistance: ohms max.
Dutf cycle:
Working voltage: volts max.
Altitude: feet max.
Operating temeratuire: -C, max.
FMYSICAL CHARACTESTICS
Case size:
Weight: poumds max.
Terminal type:
Terminal height: in. max.
ELECTRICAL TEST PROPERTIES

Dielectric withstanding volt-ge:


At sea level - volts ras
At reduced barometric pressure - volts ams
Inductance: With volts rMs, "-
-Oaamd de
applie--to (1-2): _ _ henries s n.
DC resistance: (1-2) ohms max.
Temperature rise: -'C with volts res, _ z.
"amp dc appladto (1-2) at an bient temperature
Or *c max.

(Inthe space below. provide circuit diagram)


Characteristics of trans*- Characteristir.s of trans-
C.-rar+-- 4 ;tics formers and inductorý bein( formers and inductors
submitted for qualificatloi haviatg qualification
based on similarity
"Identification data Name of manufacturer: Name of manufActurer:
Address of manufacturer: Address of manufacturer
Manufacturer's rart number Manufacturer's part number
Code assigned to Test or qualification
manufacturer: reference:
Code assijned to
__manufacturer:

Operating temperature 850 C 1550 C 850 C 155 0C


1050 C 170 0 C 1050 C 170C
1300 C > 170°C 130 0 C >170C

4Ambient temperature
(operating temperature-
"temperature rise)
External mounting
Internal mounting
"Nominal wall thickness
• • Envelope
Case dimensions
volume
Grade Grade 7 Grade 9 Grade 7 Grade 9

-Grade 8 Grade 10_ 1Grade 8 Grade 10


Wire size l1
Coating material
se material Metal Metal
Other (specify)- Other (specify)
jase finish Light gray, semigloss Light gray, semigloss

"%n..rating voltage

Pott I re
tnsulat.,on
jImpregnation
Flll' ing

Xltitude 10,000 ft. 100,.: ft.


50,OC3 ft. 50,O00 ft.

Lemina, construction,
material and finish (inclu-
ding insulating and gasket-
ing parts)

FIGURE 412 Transform -and inductor similarity comparison sleet.

,.-L 0

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