UCI274G - Winding 17

Technical Data Sheet

 UCI274G
SPECIFICATIONS & OPTIONS

STANDARDS WINDINGS & ELECTRICAL PERFORMANCE

Stamford industrial generators meet the requirements of All generator stators are wound to 2/3 pitch. This eliminates
BS EN 60034 and the relevant section of other international triplen (3rd, 9th, 15th …) harmonics on the voltage waveform
standards such as BS5000, VDE 0530, NEMA MG1-32, IEC34, and is found to be the optimum design for trouble-free supply
CSA C22.2-100, AS1359. of non-linear loads. The 2/3 pitch design avoids excessive
Other standards and certifications can be considered on request. neutral currents sometimes seen with higher winding pitches,
when in parallel with the mains. A fully connected damper
VOLTAGE REGULATORS winding reduces oscillations during paralleling. This winding,
with the 2/3 pitch and carefully selected pole and tooth
SX460 AVR - OBSOLETE designs, ensures very low waveform distortion.

With this self excited control system the main stator supplies TERMINALS & TERMINAL BOX
power via the Automatic Voltage Regulator (AVR) to the exciter
stator. The high efficiency semiconductors of the AVR ensure Standard generators are 3-phase reconnectable with 12 ends
positive build-up from initial low levels of residual voltage. brought out to the terminals, which are mounted on a cover at
The exciter rotor output is fed to the main rotor through a three the non-drive end of the generator. A sheet steel terminal box
phase full wave bridge rectifier. This rectifier is protected by a contains the AVR and provides ample space for the customers'
surge suppressor against surges caused, for example, by short wiring and gland arrangements. It has removable panels for
circuit. easy access.

AS440 AVR - STANDARD SHAFT & KEYS

With this self-excited system the main stator provides power via All generator rotors are dynamically balanced to better than
the AVR to the exciter stator. The high efficiency semi- BS6861:Part 1 Grade 2.5 for minimum vibration in operation.
conductors of the AVR ensure positive build-up from initial low
levels of residual voltage.
The exciter rotor output is fed to the main rotor through a three- INSULATION/IMPREGNATION
phase full-wave bridge rectifier. The rectifier is protected by a
surge suppressor against surges caused, for example, by short The insulation system is class 'H'.
circuit or out-of-phase paralleling. All wound components are impregnated with materials and
The AS440 will support a range of electronic accessories, processes designed specifically to provide the high build
including a 'droop' Current Transformer (CT) to permit parallel required for static windings and the high mechanical strength
operation with other ac generators. required for rotating components.

MX341 AVR QUALITY ASSURANCE

This sophisticated AVR is incorporated into the Stamford Generators are manufactured using production procedures
Permanent Magnet Generator (PMG) control system. having a quality assurance level to BS EN ISO 9001.
The PMG provides power via the AVR to the main exciter, giving
a source of constant excitation power independent of generator The stated voltage regulation may not be maintained in the
output. The main exciter output is then fed to the main rotor, presence of certain radio transmitted signals. Any change in
through a full wave bridge, protected by a surge suppressor. performance will fall within the limits of Criteria 'B' of EN 61000-
The AVR has in-built protection against sustained over- 6-2:2001. At no time will the steady-state voltage regulation
excitation, caused by internal or external faults. This de-excites exceed 2%.
the machine after a minimum of 5 seconds.
An engine relief load acceptance feature can enable full load to DE RATES
be applied to the generator in a single step.
If three-phase sensing is required with the PMG system the All values tabulated on page 6 are subject to the following
MX321 AVR must be used. reductions
We recommend three-phase sensing for applications with
greatly unbalanced or highly non-linear loads. 5% when air inlet filters are fitted.
3% for every 500 metres by which the operating altitude
MX321 AVR exceeds 1000 metres above mean sea level.
3% for every 5°C by which the operational ambient
The most sophisticated of all our AVRs combines all the features temperature exceeds 40°C.
of the MX341 with, additionally, three-phase rms sensing, for Note: Requirement for operating in an ambient exceeding
improved regulation and performance. 60°C must be referred to the factory.
Over voltage protection is built-in and short circuit current level
adjustments is an optional facility. NB Continuous development of our products entitles us to
change specification details without notice, therefore they must
not be regarded as binding.

Front cover drawing typical of product range.

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 UCI274G
WINDING 17
CONTROL SYSTEM SEPARATELY EXCITED BY P.M.G.
A.V.R. MX321 MX341
VOLTAGE REGULATION ± 0.5 % ± 1.0 % With 4% ENGINE GOVERNING
SUSTAINED SHORT CIRCUIT REFER TO SHORT CIRCUIT DECREMENT CURVES (page 5)

CONTROL SYSTEM SELF EXCITED

A.V.R. SX460 AS440
VOLTAGE REGULATION ± 1.5 % ± 1.0 % With 4% ENGINE GOVERNING
SUSTAINED SHORT CIRCUIT SERIES 4 CONTROL DOES NOT SUSTAIN A SHORT CIRCUIT CURRENT

INSULATION SYSTEM CLASS H

PROTECTION IP23
RATED POWER FACTOR 0.8
STATOR WINDING DOUBLE LAYER CONCENTRIC
WINDING PITCH TWO THIRDS
WINDING LEADS 12
STATOR WDG. RESISTANCE 0.026 Ohms PER PHASE AT 22°C SERIES STAR CONNECTED
ROTOR WDG. RESISTANCE 1.69 Ohms at 22°C
EXCITER STATOR RESISTANCE 20 Ohms at 22°C
EXCITER ROTOR RESISTANCE 0.091 Ohms PER PHASE AT 22°C
R.F.I. SUPPRESSION BS EN 61000-6-2 & BS EN 61000-6-4,VDE 0875G, VDE 0875N. refer to factory for others
WAVEFORM DISTORTION NO LOAD < 1.5% NON-DISTORTING BALANCED LINEAR LOAD < 5.0%
MAXIMUM OVERSPEED 2250 Rev/Min
BEARING DRIVE END BALL. 6315-2RS (ISO)
BEARING NON-DRIVE END BALL. 6310-2RS (ISO)
1 BEARING 2 BEARING
WEIGHT COMP. GENERATOR 580 kg 598 kg
WEIGHT WOUND STATOR 225 kg 225 kg
WEIGHT WOUND ROTOR 210.35 kg 199.39 kg
WR² INERTIA 1.7674 kgm2 1.7169 kgm2
SHIPPING WEIGHTS in a crate 613 kg 630 kg
PACKING CRATE SIZE 123 x 67 x 103(cm) 123 x 67 x 103(cm)
TELEPHONE INTERFERENCE THF<2% TIF<50
COOLING AIR 0.617 m³/sec 1308 cfm
VOLTAGE SERIES STAR 600V
VOLTAGE PARALLEL STAR 300V
VOLTAGE SERIES DELTA 346V
kVA BASE RATING FOR REACTANCE
225
VALUES
Xd DIR. AXIS SYNCHRONOUS 1.77
X'd DIR. AXIS TRANSIENT 0.15
X''d DIR. AXIS SUBTRANSIENT 0.10
Xq QUAD. AXIS REACTANCE 1.07
X''q QUAD. AXIS SUBTRANSIENT 0.13
XL LEAKAGE REACTANCE 0.07
X2 NEGATIVE SEQUENCE 0.11
X0 ZERO SEQUENCE 0.07
REACTANCES ARE SATURATED VALUES ARE PER UNIT AT RATING AND VOLTAGE INDICATED
T'd TRANSIENT TIME CONST. 0.038s
T''d SUB-TRANSTIME CONST. 0.012s
T'do O.C. FIELD TIME CONST. 1.0s
Ta ARMATURE TIME CONST. 0.01s
SHORT CIRCUIT RATIO 1/Xd

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 UCI274G
Winding 17
SX Locked Rotor Motor Starting Curves

600V
30

25
.

20
PER CENT TRANSIENT VOLTAGE DIP

15

10

0
0 100 200 300 400 500 600 700
LOCKED ROTOR kVA

MX

600V
30

25
.

20
PER CENT TRANSIENT VOLTAGE DIP

15

10

0
0 100 200 300 400 500 600 700 800 900
LOCKED ROTOR kVA

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 UCI274G
Winding 17

THREE PHASE EFFICIENCY CURVES

Three-phase Short Circuit Decrement Curve. No-load Excitation at Rated Speed

Based on star (wye) connection.
10000

SYMMETRICAL

ASYMMETRICAL
1000
CURRENT (Amps)

100

10
0.001 0.01 0.1 1 10
TIME (secs)

Sustained Short Circuit = 800 Amps

Note
The following multiplication factor should be used to convert the values from curve for the
various types of short circuit :

3-phase 2-phase L-L 1-phase L-N

Instantaneous x 1.00 x 0.87 x 1.30
Minimum x 1.00 x 1.80 x 3.20
Sustained x 1.00 x 1.50 x 2.50
Max. sustained duration 10 sec. 5 sec. 2 sec.
All other times are unchanged

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 UCI274G
Winding 17 / 0.8 Power Factor

RATINGS
60Hz
Class - Temp Rise Cont. F - 105/40°C Cont. H - 125/40°C Standby - 150/40°C Standby - 163/27°C
Series Star (V) 600 600 600 600
Parallel Star (V) 300 300 300 300
Series Delta (V) 346 346 346 346
kVA 206.3 225.0 240.0 246.3

kW 165.0 180.0 192.0 197.0

Efficiency (%) 93.0 92.8 92.6 92.6

kW Input 177.4 193.9 207.3 212.9

Dimensional and Torsional Drawing

For dimensional and torsional information please refer to the alternator General Arrangement and rotor drawings
available on our website (http://stamford-avk.com/)

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UCI274G-17-TD-EN-SG-B