t1000 Plus Application Guide

DATE: 06/09/2011 DOC.MIE91093 REV. 1.
34
T1000 PLUS
APPLICATION GUIDE
DOC. MIE91093 Rev. 1.34 Page 2 of 145
REVISIONS SUMMARY VISA

N PAGE DATE
1 All 20/10/2008 Issued Lodi
1.28 11, 13-15 2/02/2010 Added test header Lodi
1.28 100-111 1/10/2010 Differential relay Lodi

-1 test with TD1000
1.30 75 - 83 21/3/2011 Modified the Lodi
recloser test
1.34 71-83; 6/9/2011 Minor changes to Lodi
131-134 the recloser test;
added the CT
saturation test
SHORT FOREWORD ............................................................................. 7

SAFETY AT WORK................................................................................. 8
INTRODUCTION .................................................................................. 11
1 APPLICATION EXAMPLES........................................................... 14
1.1 OVERCURRENT RELAY TESTING .......................................................... 16
1.1.1. Introduction ..................................................................... 16
1.1.2. Connection to current outputs ............................... 17
1.1.3. I> Threshold and drop-off ......................................... 19
1.1.4. I>> Threshold and drop-off ..................................... 20
1.1.5. Trip and drop-off timing ............................................. 21
1.2 OVER AND UNDER VOLTAGE ................................................................ 21
1.2.1. Introduction ..................................................................... 21
1.2.2. Connection to voltage output .................................. 22
1.2.3. V> Threshold and drop-off ........................................ 24
1.2.4. V< Threshold and drop-off ........................................ 24
1.2.6. Hint: how to test a three-phase voltage relay25
1.2.7. Hint: vector group test for a PT transformer . 26
1.3 DC VOLTAGE RELAY TESTING ............................................................. 28
1.3.1. Introduction ....................................................................... 28
1.3.3. V< Threshold and drop-off ........................................ 30
1.4 REVERSE POWER RELAY TESTING....................................................... 32
1.4.1. Introduction ....................................................................... 32
1.4.2. Connection of the relay .............................................. 33
1.4.3. P% Threshold and drop-off ...................................... 37
1.4.4. Threshold and drop-off of other points ............. 37
1.5 DIRECTIONAL RELAY TESTING ............................................................ 39
1.5.1 Introduction ........................................................................ 39
1.5.2. Connection of the relay .............................................. 41
1.5.3. MTA and angle sector ................................................... 44
1.5.4. V-I curve test .................................................................... 46
1.6 OVER AND UNDER FREQUENCY RELAY TESTING ................................ 48
1.6.1. Introduction ..................................................................... 48
1.6.3. F> Threshold and drop-off ........................................ 50

1.6.4. F< Threshold and drop-off ........................................ 51
1.6.5. F>> Threshold and drop-off ..................................... 51
1.6.6. F<< Threshold and drop-off ..................................... 52
1.7 FREQUENCY RATE OF CHANGE RELAY TESTING ................................. 54
1.7.1. Introduction...................................................................... 54
1.7.3. MXROC Threshold ........................................................... 57
1.7.4. F>> Threshold and drop-off ..................................... 58
1.7.5. T2 trip and drop-off timing ....................................... 58
1.7.6. F> threshold ...................................................................... 58
1.8 SYNCHRONIZING RELAY TESTING....................................................... 60
1.8.1 Introduction ........................................................................ 60
1.8.2. Connection to voltage outputs ................................ 61
1.8.3. Voltage threshold and drop-off .............................. 63
1.8.4. Angle threshold ................................................................ 64
1.8.5. Frequency threshold ..................................................... 64
1.9 TIMER TEST.......................................................................................... 68
1.10 LOSS OF FIELD RELAY TESTING ....................................................... 69
1.11 AUTOMATIC RECLOSER TESTING...................................................... 73
1.11.1 Introduction ..................................................................... 73
1.11.2 Normal Recloser test ................................................... 76
1.11.3 Normal recloser test programming .................... 80
1.11.4 Pole mounted CB test .................................................. 82
1.11.5 Pole mounted CB test programming .................. 85
1.12 DISTANCE RELAY TESTING ............................................................... 87
1.12.1 Introduction ..................................................................... 87
1.12.2 Definition of terms ........................................................ 89
1.12.3. Relay connection .......................................................... 90
1.12.4 Test conduction .............................................................. 92
1.12.5 Single phase fault.......................................................... 93
1.12.6 Phase to phase fault .................................................... 97
1.12.7 Three phase fault ......................................................... 101
1.13 TEST OF CONVERTERS .................................................................... 105
1.14 TEST OF ENERGY METERS ............................................................... 107
1.15 TRANSFORMER DIFFERENTIAL RELAY TESTING WITH D1000 OR
TD1000 PLUS .......................................................................................... 112
1.15.1 Introduction ................................................................... 112
1.15.2 The transformer ........................................................... 112
1.15.3 The Restraint and the Differential current ... 114

1.15.4 Connection to the relay ....................................... 115
1.15.5 Characteristic curve test ..................................... 119
1.15.6 Displaying characteristic with X-Pro 1000
121
1.15.7 Connections for different transformers ..... 123
1.15.8 Second harmonic restraint test ...................... 124
1.16 PRIMARY END TO END TEST...................................................... 125
1.16. 1 Test setup ....................................................................... 127
1.16.2 Use of SWT3 ................................................................... 129
1.16.3 T1000 PLUS setup for End to End test ............ 130
1.16. 4 Line differential tests .............................................. 131
1.17 THERMAL RELAY TESTING ............................................................... 132
1.18 LOW-VOLTAGE AND MEDIUM VOLTAGE CIRCUIT BREAKER TESTS133
1.18.1. Introduction ................................................................. 133
1.18.2. Connection to current outputs .......................... 134
1.18.3. I> Threshold ................................................................. 135
1.18.4. Intervention curve .................................................... 136
1.19 CT SATURATION KNEE TEST........................................................... 136
1.19.1. Introduction ................................................................. 136
1.19.2. Test set connection ................................................. 137
1.19.2. Test execution ............................................................ 138
APPENDIX 1 OVERCURRENT RELAYS ..................................... 140
Disclaimer
Every effort has been made to make this material complete, accurate, and up-to-
date. In addition, changes are periodically added to the information herein; these
changes will be incorporated into new editions of the publication. ISA S.R.L reserves
the right to make improvements and/or changes in the product(s) and/or the
program(s) described in this document without notice, and shall not be responsible
for any damages, including but not limited to consequential damages, caused by
reliance on the material presented, including but not limited to typographical errors.
Copies, reprints or other reproductions of the content or of parts of this publication

shall only be permitted with our prior written consent.
All trademarks are the property of their respective holders.
Copyright 2012© ISA S.R.L. Italy – All rights reserved.

SH O R T FO REW O RD
Dear T1000 PLUS user,
I often wondered why the user’s manual is not very much

used, even if it includes valuable information. As me too I am
a user of such manuals, the answer I have given myself is that
valuable information are concealed somewhere in the thick
thing, and I do not have time to waste to find it. So, either the
manual is actually of help, or I ignore it.
This is why I decided to split the T1000 PLUS manual in three:

specification, with all performance details; application manual,
with instructions about how to use it one its operation is
understood; introductory guide, with the device description
and basic information. The idea is that you may read once the
introductory guide or the specification, while you need to
follow application examples more than once; so, why not to
split the manual in three?
Have a good work with T1000 PLUS!
Primo Lodi
Q&A Manager
S AFE TY AT W O R K
The Product hereafter described is manufactured and

tested according to the specifications, and when used for
normal applications and within the normal electrical and
mechanical limits will not cause hazard to health and safety,
provided that the standard engineering rules are observed
and that it is used by trained personnel only.
The application guide is published by the Seller to be used

together with the Product described in the corresponding
document. The Seller reserves the right to modify the guide
without warning, for any reason. This includes also but not
only, the adoption of more advanced technological solutions
and modified manufacturing procedures, and also the addition
of other features, not available in the first release.
The Seller declines any difficulties arising from unknown

technical problems. The Seller declines also any responsibility
in case of modification of the Product or of any intervention
not authorized by the Seller in writing.
The warranty includes the repair time and the materials

necessary to restore the complete efficiency of the Product;
so, it does not include other burdens, such as the transport
and customs fee. Under no circumstances the warrantee
includes any cost that the User may have suffered because of
the Product unavailability and downtime.
The Product is CE marked, and has been tested to operate

according to EN 61010-1, with the following operating
conditions:
. Pollution degree 2: normally, non conductive pollution

occurs;
. Measurement category 2, for measurement inputs.
Would the test set be used beyond these limits, the
safety of the test set could be impaired.
Mains supply characteristics are:

. Voltage: 230 AC, 50-60 Hz, or 110 VAC, 50-60 Hz;
. Power consumption: 1 kW maximum.
. The symbol
! is related to dangerous input or
output, and is located close to the following points:
- Outputs: main 0-250 V AC (500 V for E model); auxiliary 0-
250 V AC (500 V for E model); auxiliary 20 – 260 V DC;
- Inputs: AC voltage measurement (up to 600 V); START and
STOP Inputs (up to 250 V); resistors (up to 250 V).
. The symbol is located closet o the round socket.
. The symbol is located close to the mains supply

socket, that incorporates the protection fuse.
The Product generates voltages and currents that may be

lethal to the unadvertised user. Besides, in order to avoid any
danger in case of fault inside the Product, the device under
test should have the following characteristics:
. Connection cables must use safety banana sockets;
. Connection sockets must be not accessible;
. Input circuits must have an isolation degree at least equal to
the one of the product.
DO NOT OPERATE THE PRODUCT IF NOT CONNECTED TO

GROUND: BECAUSE OF FILTER CAPACITORS, THE CASE
WOULD GROW TO A VOLTAGE EQUAL TO THE HALF OF
THE SUPPLY, I.E. 110 V (or 55 V). BESIDES, IN THIS
SITUATION THERE IS NO FILTERING AGAINST
COMMON-MODE NOISE COMING FROM THE MAINS: THIS
CAN CAUSE SUDDEN FAULTS. THIS TYPE OF FAULTS IS
NOT COVERED BY THE WARRANTY.
The connection to ground is provided through the mains

supply cable; however, for added safety, the Product should
be connected to ground using the dedicated socket.
IF THE GROUND IS NOT AVAILABLE AT THE MAINS

SUPPLY, CONNECT THE TEST SET TO GROUND USING
THE DEDICATED SOCKET.
In case of doubt, please contact your Seller. The Seller, and

Manufacturer, declines any and all responsibility due to
improper usage, or any usage outside the specified limits.
I NTR O D U CT IO N
The single phase relay test set mod. T1000 PLUS is suited for
the testing and adjustments of the following types of relays;
the table lists also the paragraph that explains the test
procedure.
Type of relay IEEE code PARAGRAPH

- Distance* 21 1.12
- Synchronizing 25 1.8
- Over/under-voltage 27 - 59 1.2
- Power, varmetric or 32 - 92 1.4
wattmetric
- Under current 37 1.1
- Loss of field 40 1.10
- Reverse phase current 46 1.4
- Instantaneous overcurrent 50 1.1
- Ground fault 50N 1.1
- Timed overcurrent 51 1.1
- Power factor 55 1.4
- Directional overcurrent 67 1.5
- Directional ground fault 67N 1.5
- Automatic reclose 79 1.11
- DC voltage 80 1.3
- Frequency 81 1.6
- Frequency rate of change 81 1.7
- Motor protection 86 1.1
- Differential ** 87 1.1
- Directional voltage 91 1.5
- Tripping relay 94 1.9
- Voltage regulation 1.2
- Thermal 1.1
- Timers 1.9
* For distance relays three T1000 PLUS are necessary.

** Differential starter circuit. With T1000 PLUS and D1000 or
with the TD1000 PLUS model, it is possible to test the
characteristic.
In addition to the above, T1000 PLUS can test:

. Converters: V; I; φ°; p.f.; W; VAr; f., both 0 to 5 and 4 to
20 mA.
. Energy meters, single phase or three phase.
The instrument contains three separate generators:

. Main generator, which generates either AC current, AC
voltage; DC voltage;
. Auxiliary AC voltage generator, that generates an
independent, phase shifting AC voltage;
. Auxiliary DC voltage generator, that generates the DC
voltage that feeds the relay under test.
All outputs are adjustable and metered at the meantime on

the large, graphic LCD display. With the multi-purpose knob
and the LCD display it is possible to enter the MENU mode that
allows setting many functions, which make T1000 PLUS a very
powerful testing device, with manual and semi-automatic
testing capabilities, and with the possibility to transfer test
results to a PC via the USB interface. These results can be
recorded, displayed and analyzed by the powerful TDMS
software, which operates with all WINDOWS versions, and
allows creating a data base of all tests in the plant.
The basic T1000 PLUS function is to generate current and

voltages and to stop generation as the relay trips. Test results
are kept in memory, and can be transferred to a PC at a later
time, along with settings.
The ease of operation has been the first goal of T1000 PLUS:
this is why the LCD is graphic, and so large. With it, the
dialogue in MENU mode is made easy. Besides, all T1000 PLUS
outputs are continuously measured, and output values are
displayed, with no extra effort to the operator. Also the show
waveform feature can be of help: any doubt about strange
measurements, distortion and so on can be solved.
This is also why we have added the reduced power feature.

Modern relays have a very low burden. As current output is a
low impedance voltage generator, adjusting low currents
and/or current on low burdens is quite difficult because one
has to operate at the very beginning of the adjustment knob.
In this situation it is possible to connect resistors in series;

however, one must be careful not to exceed the maximum
current rating, and the wiring is more complicated. The
solution to this problem is just to reduce the available power:
this is easily performed via the multi-function knob. With less
power, the maximum voltage is reduced by a factor of 4.4; the
adjustment span on the knob is increased accordingly.
Additional features are:

. Two meters, current and voltage, with independent inputs,
allow measuring T1000 PLUS outputs or any other source;
. Two auxiliary contacts, that switch at test start, and reset
with STOP input, allows simulating the circuit breaker;
. A set of resistors allows easing output adjustment.
The instrument is housed in a transportable aluminum box,

that is provided with removable cover and handles for ease of
transportation.
NOTE: WINDOWS is a trademark of MICROSOFT inc.

1 A PP L IC AT IO N E X AM PL E S
In this paragraph, and the following ones, we describe how to

operate to test the relay. The description of why we operate
this way and of which are test set features are given in the
following chapters. So, read the following chapters the first
time you use T1000 PLUS, and then, once learned about it,
apply what you learned as follows.
The following examples include all information related to the

test. As a consequence, there is repetition passing from one
test to the next; however, we preferred to arrange the manual
so that it was not necessary to read other paragraphs than the
relevant one.
The first general comment is that when you save the result,
following data are always saved:
. Main current, or main AC voltage, or main DC voltage,
according to the selection performed with the push-button
(57);
. Auxiliary AC voltage;
. Auxiliary DC voltage;
. Timing.
If other measurements are selected by the menu, they will
also be saved along with these data.
As a consequence, there will be test results that can be not
relevant for the test: for instance, Vaux when the relay is an
over-current one.
The second comment is about saving test results. Before

performing a test, it is important to program the test
header, that includes the following information:
 Plant name;
 Operator;
 Serial number (of the relay under test);
 Model/manufacturer (of the relay under test);
 Feeder (protected by the relay).
The header is found selecting Results > Header.
All tests performed after setting the header will be grouped

together: the TDMS software will group them together, and
will allow to show test results with a single result table and
diagram. Once a relay has been tested, it is important to
change at least the relay serial number, so that results of
different relays are not mixed together. If a relay has more
than one curve, it is possible to give different headers, just by
adding a suffix letter to the serial number.
Once selected the Header, the following window is displayed.
The operation to input the header is the following.

 After having entered, if you move the knob it will move
between: arrow up; Plant name; arrow down, Return.
 If you press the arrow up or down, you will scroll
through: Plant name, Operator, Serial number,
Model/manuf., Feeder.
 Once you have reached the desired description, select
it and press: the description goes in reverse, and you
can edit it.
 The editor is performed as follows. If you turn the
knob, it will reach a number of selections in the bottom,
and then the line with the alphabet letters; at the end
of this, there is a double arrow, that, if pressed,
replaces letters with digits.
 The input is performed reaching for a letter with the
knob, and pressing it: the letter is copied into the
description. After the letters, you can select also: /_., .
 Commands on the bottom line are: Delete the letter
after the cursor; Delete all the description; move one
letter left; move one letter right; OK, to be pressed at
the end of the editing, before going to another
description.
 At the end of all editing, press the return arrow.
During a test, results can be memorized selecting Test

control > Save. Four selections are available:
 Don’t save;
 Automatic at trip;
 Confirm at trip;
 Manual.
With the selection Automatic at trip, data are immediately

saved as soon as the relay trips: this is to be selected when a
series of ON+TIME tests are performed.
With the selection Confirm at trip, as soon as the relay trips it
is possible to save data pressing MENU and then Yes: this is to
be selected when you are adjusting parameters and you want
to be sure to save the correct data. Save is performed both in
ON mode and in ON+TIME mode.
With the selection Manual, it is possible to save data at any

time, pressing MENU and then Yes, even if the relay did not
trip. As already explained, a threshold is verified with two
tests: with a value the relay trips, with a slightly different
value the relay does not trip. This is to be selected when you
are looking for the no-trip limit of a threshold.
Once results are saved, it is possible to review or to delete

them with the command Results > Show results. The
display shows the list of the relay serial numbers, followed by
the number of tests performed with the same header.
Pressing on the relay serial number you access a window with:

Plant name, Serial number, operator. You can: return, delete
escape. Pressing Delete, a confirmation message is displayed.
Pressing Yes, all results are deleted; pressing No, you return
to the results list.
If you go to the number of tests and press, tests are shown

one after the other, as they have been recorded. Here you can
read the results, and delete the ones that you want, after
confirmation.
1.1 OVERCURRENT RELAY TESTING
1.1.1. Introduction
There are many families of time-dependent overcurrent relays.

Appendix 1 gives information about how to design the nominal
curve, staring from the setting parameters.
For the test of undercurrent relays, the following notes are to

be used the other way round: the drop-off test becomes the
threshold test; the threshold test becomes the drop-off test.
The following is the connection schematic.
1.1.2. Connection to current outputs
. Power-on T1000 PLUS, acting on switch (2): the internal light

turns on.
. Set the current adjustment knob (6) completely counter-

clockwise.
. If you wish to use the DC voltage output to supply the relay

under test, press the button (69), then use knob (20) to
adjust the voltage value, that is displayed on the LCD display
(23). Connect the DC supply input of the relay to sockets (63).
. Connect the relay to the two main current output sockets

(13) that correspond to the current to be generated. For the
sake of accuracy and ease of adjustment, select the smallest
range greater that the desired current.
. Connect the TRIP output to the STOP input.

. Select the connection socket measurement pressing the
push-button (57): the LED turns on. This enables current
output measurement. WARNING: if you do not select the
output socket, the test displays false current or voltage values.
. Select ON and check if you can easily adjust the desired

current, acting on knob (6). If the current is reached with a
rotation less than one fifth of the total, this means that the
burden is very low. In this instance, reduce the output power
with the following menu commands:
Test control > Test power > 60 VA > ESC
The 60 VA LED turns on. Select ON again, and check that the
desired current can be reached with ease of adjustment; if the
current is not reached, go back and select 300 VA.
. Next steps depend upon the type of relay and upon the type
of test you want to perform. The following example applies to
an overcurrent relay with a time-dependent curve and one (or
more) time-independent threshold. Of this relay we want to
find and save trip and drop-off thresholds, and also the time-
dependent curve.
. Set the save function, as follows.

Test control > Save > Confirm at trip > ESC
. Set the timer with the following selections:

Timer start/stop > START > INT (RET)
STOP > EXT > Clean (Voltage) (RET)
Edge ESC
NOTE: stop clean or voltage according to the relay trip contact
connections.
1.1.3. I> Threshold and drop-off
The first session is finding threshold I>. Select ON; slowly

increase the current. As the relay trips, pressing the multi-
function knob tripping values can be saved. The TRIP LED (43)
turns on for 5 seconds; during 5 seconds, parameters at trip
are displayed; then, the standard measurement is restored.
Confirm save results pressing the multi-function knob, and
proceed.
NOTE: stored value is the current as the relay trips. This
corresponds to the relay threshold only if the current did not
change very much while the relay timing elapsed, so current
should be increased quite slowly. A more accurate threshold
measurement can be found if the starter contact is available.

If threshold measurement was not good because you were
moving too fast, do not confirm test results and repeat the
test.
Next, we find the drop-off threshold for I>.

From the trip current above, slowly decrease the current; as
the relay resets, save test result.
NOTE: stored value is the current as the relay resets; as reset
timing is usually very short, current does not change very
much at drop-off, and the measurement is accurate.
1.1.4. I>> Threshold and drop-off
The second session is finding threshold I>>. The problem is

that the test result criterion is no more to find the limit
between no trip and trip; it is instead to find the limit between
two different timings: what we have shown as t>, for currents
less than I>>, and t>> for currents more than I>>. There are
many ways to perform the test; we suggest taking advantage
of the Timed generation option, as follows.
. Start from a current more than I>; select ON+TIME, and

check for time response. Take note of the timing t>. Compute
tmax as 80% of t>.
. Set the Timed test, as follows.
Test control > Fault injection > Timed > tmax (RET)
. Select ON+TIME, and start the test: the test goes OFF with
no message. Slowly increase the test current, until the relay
trips within tmax: this is the threshold; pressing the multi-
function knob tripping values can be saved.
NOTE: stored value is the current as the relay trips. This

change very much while the relay timing elapsed; however,
for this threshold the timing is short, so the measurement is
accurate.
Next, we find the drop-off threshold for I>> NOTE: this

parameter can be found only if there is a separate trip for the
instantaneous threshold; else, if there is only one contact, it is

impossible to be measured..
. Select the Maintained test control mode:
Test control > Fault injection > Maintained (RET)
. Press ON from the trip current above.

. Slowly decrease the current; as the relay resets, pressing the
multi-function knob, the reset value can be saved.
1.1.5. Trip and drop-off timing
Now we can measure trip timings, following the I-t curve with
as many points as desired. First thing, restore the Maintained
fault injection, as follows
Test control > Fault injection > Maintained (RET)
Then select the NO or NC level for the relay trip contact:
Timer start/stop > STOP > EXT > Clean (Voltage) > NO
(NC) ESC
Now, press ON and pre-adjust the first test current: as the
relay trips, don’t save test result; go OFF. Select ON+TIME: as
the relay trips, test goes OFF; pressing the multi-function knob
tripping values can be saved. The TRIP LED (43) turns on and
parameters at trip are displayed until ON or ON+TIME are
selected. Confirm save results pressing the multi-function
knob, and proceed with other test currents, until all points to
be tested are measured.
Now we can measure the drop-off timing. First thing, select

the NC or NO level for the relay reset contact:
Timer start/stop > STOP > EXT > Clean (Voltage) > NC
(NO) ESC
Now, press ON and pre-adjust the current. Select OFF+TIME:
as the relay resets, pressing the multi-function knob drop-off
values can be saved. Confirm save results pressing the multi-
function knob, and proceed.
1.2 OVER AND UNDER VOLTAGE
1.2.1. Introduction
Voltage relays often have an overvoltage and an undervoltage

threshold: for this reason, in the following we use the auxiliary
voltage generator, that allows setting the pre-fault and the
fault voltage independently of each other. For overvoltage
relays it is also possible to use the main output.
1.2.2. Connection to voltage output

turns on.
. Press the button (70) to have the AC voltage available.

. If you use the auxiliary AC voltage, as suggested, first select

the auxiliary voltage range, then select the pre-fault + fault
mode as follows.
AUX VAC/VDC > Aux VAC control > Range (RET)

Mode > Pre-fault+fault > Pre-
fault amplitude > (Value) ESC
The range should be the closest one to the high threshold to
be generated. The pre-fault amplitude is adjusted by the
multi-function knob and display; the value is computed from
the nominal relay (phase – to – phase) voltage VN:
V pre-fault = VN/1.73
Standard values are: 57.8 V for VN = 100 V; 63.5 V for VN =
110 V.
After this adjustment the pre-fault voltage is generated
prior to all tests. Select ON: as the test is started, the
voltage goes to the fault value, that is adjusted by the knob
(20). Pre-adjust the fault value at the same value as the pre-
fault.
. Next steps depend upon the type of relay and upon the type
of test you want to perform. The following example applies to
an overvoltage and undervoltage relay with one (or more)
time-independent threshold. Of this relay we want to find and
save trip and drop-off thresholds.
VN
. Set the “Automatic save at trip” function, as follows.



Edge ESC
connections.
1.2.3. V> Threshold and drop-off
The first session is finding threshold V>. Select ON; slowly

increase the auxiliary AC voltage. As the relay trips, confirm
save results pressing the multi-function knob, and proceed.
NOTE: stored value is the voltage as relay trips. This
trip timing is usually short, so current does not change very
much at release, and the measurement is accurate.
If threshold measurement was not good because you were
moving too fast, do not confirm test results and repeat the
test.
Next, we find the drop-off threshold for V>. From the voltage
above, slowly decrease the voltage; as the relay resets,
pressing the multi-function knob tripping values can be saved.
The TRIP LED (43) turns on for 5 seconds; during 5 seconds,
parameters at reset are displayed; then, the standard
measurement is restored.
NOTE: stored value is the voltage as the relay resets. This
corresponds to the relay drop-off only if the current did not
reset timing is usually very short, so current does not change
very much at release, and the measurement is accurate.
1.2.4. V< Threshold and drop-off
The second session is finding threshold V<. Select ON; slowly

decrease the auxiliary AC voltage. As the relay trips, confirm
Next, we find the drop-off threshold for V<. From the voltage
above, slowly increase the voltage; as the relay resets,
confirm save results pressing the multi-function knob, and
proceed.
Now we can measure trip timings, following the V-t curve with
as many points as desired.
Press ON and pre-adjust the first test voltage (either more
than V> or less than V<): as the relay trips, don’t save test
result; go OFF. Select ON+TIME: as the relay trips, test goes
OFF; pressing the multi-function knob tripping values can be
saved. The TRIP LED (43) turns on and parameters at trip are
displayed until ON or ON+TIME are selected. Confirm save
results pressing the multi-function knob, and proceed with
other test voltage, until all points to be tested are measured.

the NO (or NC) level for the relay reset contact:
(NO) ESC
Now, press ON and pre-adjust the voltage at a value where
the relay trips. Select OFF+TIME: as the relay resets, pressing
the multi-function knob drop-off values can be saved. Confirm
1.2.6. Hint: how to test a three-phase voltage relay
If you have a three phase voltage relay to test, how can you
do it given the fact that T1000 PLUS only has two voltage
generators? The problem can be easily solved using the two
available voltages with a phase shift of 60°, and connecting
them as phase to phase voltages rather than phase voltages.
The drawing gives the idea.
V MAIN
VN
V AUX
The two voltages shold have the same amplitude, equal to the
phase to phase voltage: the connections is shown here below.
With this connection, the VN socket of the relay is not

connected: the VN point will be created by the relay input
transformers.
1.2.7. Hint: vector group test for a PT transformer

There's an easy way to check the power transformer vector

group. Please make reference to the following wiring diagram.
 Connect V main to the transformer HV side phase 1 and

2 (positive and negative).
 Connect V aux to the transformer HV side phase 2 and
3 (positive and negative).
 Adjust the same voltage value on both generators.
 Adjust 240° for Vaux with respect to the mains.
 Connect the measuring input Ext V (the 600 V or the
10 V input, as a function of the transformer ratio) to LV
side terminals 1 and 2.
 Select the measurement of the ExtV - Vmain phase
angle.
This way, we are generating a three phase voltage on HV side,

all voltages with 120° phase shift. But, since phase angle of
V12is 0°, the phase shift measured on ExtV per respect to
Vmain, divided by 30, gives you the transformer group.
Suppose you measure 150°, the transformer group would be
150/30=5.
1.3 DC VOLTAGE RELAY TESTING
1.3.1. Introduction
DC voltage relays usually have an undervoltage threshold

only. We perform the test using the main DC voltage output,
because the auxiliary DC voltage is continuously generated,
and cannot be used for trip timing tests. The following is the
connection schematic.

turns on.

clockwise.
. Connect the relay to the two main DC voltage output sockets

(61).
. Select the socket measurement pressing the push-button

(57): the LED turns on. WARNING: if you do not select the
output socket, the test displays false voltage values.
. The following example applies to an undervoltage relay with

one (or more) time-independent threshold. Of this relay we
want to find and save trip and drop-off thresholds.


Edge ESC
connections.
1.3.3. V< Threshold and drop-off
The first session is finding threshold V<. Select ON; increase

the DC voltage to VN. The relay will reset; do not confirm the
value. Now slowly reduce the voltage; as the relay trips,
proceed.
change very much while the relay timing elapsed. If threshold
measurement was not good because you were moving too
fast, do not confirm test results and repeat the test.
Next, we find the drop-off threshold for V<. From the voltage
above, slowly increase the voltage; as the relay resets,
NOTE: stored value is the voltage as the relay resets. This
corresponds to the relay drop-off only if the current did not
reset timing is usually very short, so current does not change
very much at release, and the measurement is accurate.
Now we can measure trip time: as the DC voltage is removed

when we start the test, we have only one value.
Press ON and pre-adjust the nominal voltage VN. Select
OFF+TIME: as the relay trips, test goes OFF; pressing the
multi-function knob tripping values can be saved. The TRIP
LED (43) turns on and parameters at trip are displayed until
ON or ON+TIME are selected. Confirm save results pressing
the multi-function knob, and proceed with other test voltage,
until all points to be tested are measured.

(NO) ESC
Now, press ON+TIME: as the relay resets, pressing the multi-
function knob drop-off values can be saved. Confirm save
results pressing the multi-function knob, and proceed.
1.4 REVERSE POWER RELAY TESTING
1.4.1. Introduction
Reverse power relays can be either wattmetric or varmetric.

The following note applies to both of them; the only difference
is the phase angle between current and voltage.
Reverse power relays normally protect generators against

reverse power. In fact, when the active power flows from the
network to the generator, it means that the generator works
as a motor (that’s the reason why, sometimes, these
protective relays are called anti-motoring relays). This may
cause serious problems because the generator receive power
from either turbine and network.
Therefore this power will be transformed in:

 Kinetic energy: the generator accelerates;
 Thermal energy: the temperature increases.
MOTOR GENERATOR
Q
Forbidden
zone Eo jXsI I
ZS

RsI
V Q E0
 I V
P
P
In other words, if the flux of power is not promptly

interrupted, the life of the generator is seriously in danger.
Referring to the above scheme, the voltage V is locked to the

network. If the phase angle of the current is higher than 90°,
this means that the active power P is negative (working point
in 2nd or 3rd quadrant).
The test is performed using the main current generator and

the auxiliary voltage generator, at different phase shifts.
Parameters involved are three: voltage; current; phase shift;
so, in the following, the test is performed at nominal voltage,
selecting the phase angle and changing the current to find the
threshold at the selected angle.
As the setting is in percent of the nominal power, it is possible

to use the power measurement, that is available on T1000
PLUS.
1.4.2. Connection of the relay


turns on.

clockwise.

. First select the auxiliary AC voltage range, as follows.

AUX VAC/VDC > Aux VAC control > Range (ESC)
The range should be the closest one to the high threshold to

be generated. The fault amplitude is adjusted by the multi-
function knob and display; the value is computed from the

nominal relay (phase – to – phase) voltage VN:
110 V.
After this adjustment the fault voltage is generated
prior to all tests, and is adjusted by the knob (20).
. Connect the relay current input to the two main current

output sockets (13) that correspond to the current to be
generated. For the sake of accuracy and ease of adjustment,
select the smallest range greater that the desired current.
NOTE: in case of three phase relay, connect all currents in
series.


current is not reached, go back and select 300 VA.
. Connect the relay voltage input to the two auxiliary AC

voltage output sockets (62).
NOTE: in case of three phase relay, connect all voltages in
parallel.
. As this is a power relay, it is possible to check directly the P-

Q curve, selecting in Other measurements the display of P and
Q. This is performed the following way.
METERS > OTHER > INTERNAL > P-Q ESC
The display shows P and Q along with current, voltage and
angle.
. The relay has a nominal power PN; the threshold is a

percentage of PN, P%. From PN compute the nominal current
IN = PN *1.73/ VN.
NOTE: in case of three phase relay, IN shall be divided by
three.

Edge ESC
connections.
. Next step serves to ascertain that the relay is correctly

connected; to this purpose we perform two tests in opposite
directions. The angle between current and auxiliary voltage is
set as follows.
AUX VAC/VDC > Aux VAC control > Phase > Reference :
Current > (adjust phase) ESC
NOTE: the adjustment can be performed only after having
adjusted the current output. The two tests are:
 Forward:
I = IN;  = 0°. Press ON+TIME: the relay should not
trip.
 Reverse:
I = IN:  = 180°. Press ON+TIME: the relay should
trip.
Only if the result of the direction test is correct we can proceed

with other tests.
. Next steps are the search of the points of the P-Q curve we
have selected. The key test is performed at 180°; additional
tests are decided by the operator. In general, it is wise to
execute at leas two more tests, in order to ascertain that the
curve corresponds to the nominal one. In our example we will
test at 180° (P%); 120° (P1); 240° (P2).

1.4.3. P% Threshold and drop-off
. The first session is finding P%.

. Set the current to voltage angle at 180°.
. Select ON; slowly increase the current. As the relay trips,
The TRIP LED (43) turns on for 5 seconds; during 5 seconds,
parameters at trip are displayed; then, the standard
measurement is restored. Confirm save results pressing the
multi-function knob, and proceed: the display shows the
corresponding single-phase power.
NOTE: If the relay is three-phase, power should be multiplied
by 3. This can easily be done after transferring test results to
X-PRO1000.
. Next, we find the drop-off threshold for P%. From the trip
current above, slowly decrease the current; as the relay
resets, save test result.
NOTE: stored value is the current as the relay resets; as reset
timing is usually very short, current does not change very
much at drop-off, and the measurement is accurate.
1.4.4. Threshold and drop-off of other points
. Next sessions serve to find P1, P2 threshold and drop-off.

. Set the current to voltage angle at next value.

. Select ON; slowly increase the current. As the relay trips, the
display shows the corresponding single-phase active and
reactive power. If the relay is properly set, the active power
should be the same as test before, and should display P%,
while the reactive power should be 1.73 * P%.
. Next, we find the drop-off threshold. From the trip current
above, slowly decrease the current; as the relay resets, save
test result.
Now we can measure trip timing. Press ON and pre-adjust the

test current (to more than P%): as the relay trips, don’t save
test result; go OFF. Select ON+TIME: as the relay trips, test
goes OFF; pressing the multi-function knob tripping values
can be saved. The TRIP LED (43) turns on and parameters at
trip are displayed until ON or ON+TIME are selected. Confirm
save results pressing the multi-function knob.

(NO) ESC
Then, select ON and select OFF+TIME: as the relay resets,
pressing the multi-function knob drop-off values can be
saved. Confirm save results pressing the multi-function knob,
and proceed.
1.5 DIRECTIONAL RELAY TESTING
1.5.1 Introduction
These relays are used to protect MV feeders against Earth

faults by detecting the residual voltage Vo, the residual current
Io and the relative angle. Normally the current is lagging; for
neutral isolated lines, Io  -90°; for other earth systems
(resistance, Petersen Coil), the phase angle can be less: 40°,
60°. This is also the angle of maximum sensitivity of the relay.
Since relay inputs are one current and one voltage, we’ll use I
main and V aux to perform the test.
The parameters that we will test are:
 The characteristic angle, sometimes called MTA= max
torque angle (electromagnetic relays), and the Angle
sector, that is half of the operating angle;
 The pick up of Io;
 The pick up of Vo.
When testing one parameter we have to set the other two at a
value above the pick up.
 Test MTA: we keep Vo and Io above the respective pick
ups.
 Test the Angle sector: we keep Vo and Io above the
respective pick ups.
 Test the pick up of Io: we keep Vo above the pick up,
and the current angle at the measured Characteristic
Angle.
 Test the pick up of Vo: we keep Io above the
measured pick up, and the current angle at the
measured Characteristic Angle.
In this example we’ll suppose we are testing a relay with the

characteristic displayed in the graph.
Characteristic Angle
MTA
Operating zone
Non Operating zone
Limits between operating and a non operating zone are at

around +115° and +285°. This limits can be found with an
angle search, starting from the non operating zone (IR =
180°) towards the operative zone, until the relay trips. Prior to
this, we have to make sure that the relay operates.
Also, the earth directional relay shouldn’t trip for all values of
voltage and current. It is widely accepted that a directional
relay characteristic can run inside the dotted line area, as
shown in the figure.
Characteristic Vo - Io at Io = - 90°

100 X = CURRENT [ A ]
Y = VOLTAGE [ V ]
 V1=100 V
 I1= 5 mA Phase R
We want to find this point... Lower Limit
Operating zone  V1 = 6 V
10
 I1R = 1 A
... and this point !
Non operating zone
1
0.001 0.01 0.1 1 10
Next tests serve to find some point of the characteristic curve.

Note that it is also possible to test the relay with some no-trip
test inside the non operating zone, and some trip test in the
operating zone.
1.5.2. Connection of the relay


turns on.

clockwise.

. Connect the relay current input to the two main current

output sockets (13) that correspond to the current to be
generated. For the sake of accuracy and ease of adjustment,
select the smallest range greater than the desired current.


current is not reached, go back and select 300 VA. If the
adjustment is still difficult, specially in case of low current
settings, connect a resistor of the set in series to current
output and use the external meter, that has lower
measurement ranges. As the no-load voltage output of the 10
A range is 50 V, with 470 Ohm the maximum current is 100
mA; with 1000 Ohm it is 50 mA, and with 2200 Ohm it is 22
mA.
. Connect the relay voltage input to the two auxiliary AC

voltage output sockets (62).
. Select the auxiliary voltage range and the fault mode as

follows.
Mode > Fault > ESC
The range should be the closest one to the voltage to be
generated. With this selection the auxiliary voltage is
continuously generated: we will test the relay modifying the
auxiliary voltage and the current according to the point to be
tested on the V-I curve.

Edge ESC
connections.
. Next step serves to ascertain that the relay is correctly

connected; to this purpose we perform two tests in opposite
directions. The angle between auxiliary voltage and current is
set as follows.
AUX VAC/VDC > Aux VAC control > Phase > Adjust
phase Vaux-Imain > (adjust phase) ESC
NOTE: the adjustment can be performed only after having

adjusted the current output. If the current is too low, the
measurement can be difficult; in this case, it is possible to
adjust the voltage with reference to the mains, that, in turn, is
in phase with the current.
The two tests are:

I = IN; V = VN;  = 180° + MTA. Press ON+TIME: the
relay should not trip.
I = IN; V = VN;  = MTA. Press ON+TIME: the relay

should trip.
Only if the result of the direction test is correct we can proceed

with other tests.
1.5.3. MTA and angle sector
The first tests serve to measure the MTA and angle sector. We
will perform a threshold test by moving the test point on a
circle in the V-I plane.
TAKE CARE: φ1 is the angle at which you enter the operating area,
with the positive direction of angles; φ2 is the angle at which you leave
the operating area.
In the following are shown two cases: in the first one φ1 = 0°;
φ2 = 120°; MTA = 60°. In the second one φ1 = 240°; φ2 = 30°;
MTA = 315°.
2 I I
MTA 2
TRIP AREA
V
1 MTA
TRIP AREA

. Select ON.
. Set: I = IN; V = VN;  = MTA + 180°: the relay does not
trip.
. Slowly reduce the phase shift, until the relay trips: 1 trip is
found. As the relay trips, pressing the multi-function knob
tripping values can be saved. The TRIP LED (43) turns on for 5
seconds; during 5 seconds, parameters at trip are displayed;
then, the standard measurement is restored. Confirm save
results pressing the multi-function knob, and proceed: the
display shows the corresponding single-phase power.
. From this phase angle, slowly increase the phase shift, until
the relay resets: 1 drop-off is found. As the relay resets,
saved.
. Continue to increase the phase shift, until the relay trips: 2

trip is found. As the relay trips, save the trip values.
. From this phase angle, slowly decrease the phase shift, until
the relay resets: 2 drop-off is found. As the relay resets,
saved.
From these values, compute:

1. Angle Sector Sec= |2 - 1|;
2. Half angle sector Hs = Sec/2;
3. Now, before computing the MTA, it is necessary to
verify if Hs is less or more than 90°.
a) If Hs is ≤ 90°, then: MTA = Hs + 1
b) If Hs is > 90°, then: first compute the 180°
complement of Hs, Cs = 180° - Hs; next, compute
MTA = Cs + 1.
1.5.4. V-I curve test
The V-I curve is tested setting the phase shift at MTA, and
modifying the current at constant voltage, or the voltage at
constant current. In our figure we have two points: P1 = 100
V, 5 mA; P2 = 6 V, 1 A.
Test of P1
. Press ON. Set the auxiliary voltage 100 V.
. The phase angle is not displayed with very low currents; so,
adjust the current angle to 90°, taking the mains as a
reference:
AUX VAC/VDC > Aux Vac control > Phase > Reference:
Current > (90°) ESC
. Use the 10 A range ; connect the 2200 Ohm resistor in series

to Io relay input. For a better reading, connect also in series
the 25 mA input of the external measurement, selecting this
measurement as follows:
METERS > External > 20 mA ESC
. Slowly increase the current, until the relay trips: P1 trip is

. From this current value, slowly reduce it, until the relay
resets: P1 drop-off is found. As the relay resets, pressing the
multi-function knob drop-off values can be saved.
Test of P2
. Press ON. Set the auxiliary voltage at 0 V.
. Use the 10 A range ; there I no problem with phase and
current measurements. Adjust the current to 1 A.
. Slowly increase the voltage, until the relay trips: P2 trip is

. From this voltage value, slowly reduce it, until the relay
resets: P2 drop-off is found. As the relay resets, pressing the
multi-function knob drop-off values can be saved.
Other points can be found the same way. For the sake of
accuracy, test at constant voltage down to 8 V, and at
constant current from 10 mA up.
Now we can measure trip timing.

. Press ON and pre-adjust I = IN; V = VN;  = MTA: as the
relay trips, don’t save test result; go OFF.
. Select ON+TIME: as the relay trips, test goes OFF; pressing
the multi-function knob tripping values can be saved. The
TRIP LED (43) turns on and parameters at trip are displayed
until ON or ON+TIME are selected. Confirm save results
pressing the multi-function knob.
Now we can measure the drop-off timing.

. First thing, select the NO (or NC) level for the relay reset
contact:
(NO) ESC
. Then, select ON and then select OFF+TIME: as the relay

resets, pressing the multi-function knob drop-off values can
be saved. Confirm save results pressing the multi-function
knob, and proceed.
1.6 OVER AND UNDER FREQUENCY RELAY TESTING
1.6.1. Introduction
Frequency relay monitor the frequency of generator voltage

outputs; if the upper or lower frequency threshold is reached,
the relay issues a trip command for the circuit breaker, in
order to preserve the generator safety.
The test is performed using the auxiliary voltage generator,

that allows setting the output frequency. We will take
advantage of pre-fault and fault selection, so that:
. Pre-fault output is set at nominal voltage and mains
frequency;
. Fault output has the same amplitude, but frequency is
modified according to our test.
During the test the relay is powered with nominal voltage

amplitude; as the frequency changes, amplitude and phase
are not affected .
Next steps depend upon the type of relay and upon the type of
test you want to perform. The following example applies to a
frequency relay with two high and two low thresholds; for both
we want to find and save trip and drop-off values.
The following is the connection schematic,

turns on.

. Select the auxiliary voltage range and the pre-fault + fault

mode as follows.
The range should be the closest one to the nominal voltage.

The pre-fault amplitude is adjusted by the multi-function knob
and display; the value is computed from the nominal relay
(phase – to – phase) voltage VN:
110 V.
After this adjustment the pre-fault voltage is generated prior
to all tests, as the unit is OFF. Select ON: as the test is
started, the voltage goes to the fault value, that is adjusted by
the knob (20). Adjust the fault value at the same value as the
pre-fault.
. Connect the relay to the auxiliary voltage output sockets

(62).

Test control > Save > Automatic at trip > ESC
NOTE: for other selections see the pop-up menu chapter.

Edge ESC
connections.
1.6.3. F> Threshold and drop-off
The first session is finding threshold F>. Select ON, then,

modify the output frequency as follows:
AUX VAC/VDC > Aux VAC control > Frequency > Adjust
Slowly increase the auxiliary AC frequency. As the relay trips,

the result is saved.
1
corresponds to the relay threshold only if the frequency did
not change very much while the relay timing T> elapsed, so,
frequency should be changed quite slowly. If threshold

Next, we find the drop-off threshold for F>. From the

frequency above, slowly decrease it; as the relay resets,
proceed.
NOTE: stored value is the frequency as the relay resets. This
corresponds to the relay drop-off only if the frequency did not
reset timing is usually very short, so the frequency does not
change very much at release, and the measurement is
accurate.
1.6.4. F< Threshold and drop-off
Now we find the threshold F<. Remaining ON from the above

test, slowly decrease the auxiliary AC frequency. As the relay
trips, confirm save results pressing the multi-function knob,
and proceed.
Next, we find the drop-off threshold for F<. From the

frequency above, slowly increase it; as the relay resets,
proceed.
1.6.5. F>> Threshold and drop-off
The second session is finding threshold F>>. The problem is

that the test result criterion is no more to find the limit
between no trip and trip; it is instead to find the limit between
two different timings: what we have shown as T1, for
frequencies less than F>>, and T2, for frequencies more than
F>>. There are many ways to perform the test; we suggest
taking advantage of the Timed generation option, as follows.
Set the “Don’t save” function, as follows.
Test control > Save > Don’t save ESC
Start from a frequency more than F>; select ON+TIME, and
check for time response. Increase the test current, repeat the
test until the relay trips with a delay T2. Reduce the
frequency, and take note of the timing T1. Compute tmax as

80% of T1.
Set the Save function, and Timed test, as follows.
Test control > Fault injection > Timed > tmax (RET)
Save > Confirm at trip > ESC
Select ON; increase the frequency starting from a value less
than F>>. If the relay trips within tmax, pressing the multi-
function knob tripping values can be saved; if not, the test
goes OFF with no message. In this instance, select ON again
until you find the trip. Confirm save results pressing the multi-
function knob, and proceed.
NOTE: stored value is the frequency as the relay trips. This
corresponds to the relay threshold only if the frequency did
not change very much while the relay timing elapsed;
however, for this threshold the timing is short, so the
measurement is accurate.
Next, we find the drop-off threshold for F>>. From the trip
frequency above, slowly decrease the frequency; as the relay
resets, pressing the multi-function knob tripping values can
be saved.
1.6.6. F<< Threshold and drop-off
Now we find the threshold F<<. The procedure is the same as

for F>>: measure T1 and T2, then compute tmax = 0.8*T1,
and set the timed test to find F<<.
Now we can measure trip timings, following the F-t curve with
Pre-adjust the first test frequency (either more than F> or less
than F<). Select ON+TIME: as the relay trips, test goes OFF;
The TRIP LED (43) turns on and parameters at trip are
displayed until ON or ON+TIME are selected. Confirm save
results pressing the multi-function knob, and proceed with
other test frequencies, until all points to be tested are
measured.

(NO) ESC
Now, press ON and pre-adjust the frequency at a value where
the relay trips. Select OFF+TIME: as the relay resets, pressing
the multi-function knob drop-off values can be saved. Confirm
1.7 FREQUENCY RATE OF CHANGE RELAY TESTING
1.7.1. Introduction
This type of relay monitors the line frequency and whenever a

quick variation is detected, it operates. Normally it is used to
disconnect loads from the line and to preserve the stability of
the whole network.
L oad 3
L oad 2
L oad 1
The test is performed using the auxiliary voltage generator,

that allows setting the output frequency and the frequency
rate of change (ROC). We will use the pre-fault and fault
selection, so that:
. Pre-fault output is set at nominal voltage and mains
frequency;
. Fault output has the same amplitude; frequency and ROC are
modified according to our test.
Next steps depend upon the type of relay and upon the type of
test you want to perform. The following example applies to a
frequency ROC relay with:
. A frequency range, from F< to F>, within which it does not
trip;
. Absolute min and max frequencies, F<< and F>>, below and
above which it trips in time T2;
. For frequencies between F< and F<<, or between F> and
F>>, it trips with delay T1 if ROC is more than the set
threshold MXROC; else, it does not trip. The characteristic

curve is the following.
In the dashed area the relay trips only if the ROC is higher
than the threshold.


turns on.


mode as follows.
The pre-fault amplitude is adjusted by the multi-function knob
and display; the value is computed from the nominal relay
(phase – to – phase) voltage VN:
110 V.
After this adjustment the pre-fault voltage is generated prior
to all tests, as the unit is OFF. Select ON: as the test is
started, the voltage goes to the fault value, that is adjusted by
the knob (20). Adjust the fault value at the same value as the
pre-fault.
. Connect the relay to the auxiliary voltage output sockets

(62).


Edge ESC
connections.
1.7.3. MXROC Threshold
The first session is finding the MXROC threshold; we will start

testing the positive ROC. The ROC threshold cannot be found
as usual, modifying the ROC until the relay trips: as we do, the
frequency changes, and the relay would trip because of
thresholds F>> or F<<. The following session is therefore a
series of trip tests performed at different values of ROC. The
threshold is found when we have two values of ROC, ROC(31)
and ROC(32), ROC(31) < ROC(32), where:
. For ROC(31) the relay does not trip;
. For ROC(32) the relay trips;
. The difference ROC(32) – ROC(31) is small enough for the
desired test accuracy.
First of all, set the maximum test time as 1.5 * T1, so that we
do not waste time:
Test control > Fault injection > Timed > 1.5*T1 (RET)
Save > Confirm at trip > ESC
Now, set the starting frequency to F>; then, set the first value
for ROC:
AUX VAC/VDC > Aux VAC control > Frequency > Adjust
F> (RET)
Adjust ROC
Press ON+TEST, and see if the relay trips. Two possibilities:

. Trip: don’t save the result; reduce the ROC and repeat until
the relay does not trip. Now increase the ROC again: as the
relay trips, save test result.
. No trip: increase the ROC and repeat until the relay trips: as
it does, save test result.
With this test we also measure the timing T1.
Repeat now the test, with a starting frequency equal to F<,

and with the same value for ROC, but with negative sign.
1.7.4. F>> Threshold and drop-off
The test procedure is the same as the one for the frequency
relay; tmax must be set to 0.8*T1.
1.7.5. T2 trip and drop-off timing
The test procedure is the same as the one for the frequency
relay; tmax must be set to 0.8*T1.
1.7.6. F> threshold
This threshold cannot be checked directly (unless a starting

output is available; in this instance, the test is the same as for
the frequency relay).
If no starting output is available, proceed as follows.

. Program the starting frequency = FNOM, and a ROC greater

than MXROC, say ROC(33).
. Press ON+TIME and check for the trip time Tt. This delay is
the sum of T1 plus the time it has taken to reach F> (or F<
with negative ROC); so:
. Compute F> = (Tt – T1)*ROC + FNOM
1.8 SYNCHRONIZING RELAY TESTING
1.8.1 Introduction
The purpose is to test the synchronising device that allows a

generator to be put in parallel to a live power line. There are
three conditions that must be verified:
Voltage difference below a certain  V1- V2  < 5 V

value;
Frequency difference below a  F1 - F2  < 0.1 Hz
certain value;
Angle difference below a certain  1- 2  < 5°
value.
When these three conditions are reached, the relay will give
permission to close the
switchgear and connect the
G3
generator to the power line.
These conditions are detected

SYNCHROCHECK
by measuring and comparing RELAY
V1 from the generator and V2
from the power line: we simulate this situation on T1000 PLUS
connecting an input to the main AC voltage output, and the
other one to the auxiliary voltage output. We will take
advantage of the fact that the auxiliary voltage output can
have a different amplitude, can be phase shifted, and can have
a different frequency as compared to the main AC voltage
output.
Normal synchrocheck relays measure the phase to phase

voltage on both sides of the Circuit Breaker. This means that
the voltage we need to apply might be 100V, or 110V or 115V,
depending on the nominal voltage.
Note that in the following, all tests will start from a non
synchronized condition. Consider that prior to test start the
main voltage output is OFF; so, threshold tests are performed

the following way:
. After pressing ON, values are adjusted first so that the relay
does not give permission;
. We make sure that the relay is not tripped looking at light
(42); then, we slowly modify the parameter until the relay
trips. It may occur that the relay does not trip, even if you
have reached the minimum value: this is because you moved
too fast. Normally you should reach the limit (VN, or 0°, or 50
Hz) in 20 s or more; so, in this instance, repeat the test more
slowly.
1.8.2. Connection to voltage outputs


turns on.


mode as follows.
Mode > Fault >
(RET)
After this adjustment the auxiliary voltage is generated prior
to all tests, as the unit is OFF, and during the test; the
amplitude is adjusted by the knob (20).
. Select the main AC voltage output measurement acting on

push-button (57), so that light (53) turns on.
. Connect the relay input V1 to the main AC voltage output

sockets (60), and the relay input V2 to the auxiliary voltage
output sockets (62).
. Set the “Confirm at trip” function, as follows.


Edge ESC
connections.
1.8.3. Voltage threshold and drop-off
We start from a situation where:

. Amplitudes are different;
. Phase is 0°;
. Frequency is the same (the mains).
From this, we will modify an amplitude, until the relay trips:
this is the voltage threshold. There are two thresholds, above
and below VN: the test will be performed first with V2 > V1,
and then with V2 < V1.
. Press ON, and adjust V1 to VN.
. Press OFF, and adjust the value of V2 to a value greater than
VN, that is outside the permission (for instance, 110 V).
. Now, press ON again, check that the relay is not tripped, and
slowly reduce the voltage until the relay trips: at this moment,
proceed: the high voltage threshold V> is found.
NOTE: Stored values are the voltages as relay trips. This
corresponds to the relay threshold only if the voltage did not
change very much while the relay relay timing T1 elapsed;
soothe voltage should be changed quite slowly. If threshold
. Next, we find the drop-off threshold for V>. From the voltage
above, slowly increase it; as the relay resets, confirm save
NOTE: stored values are the voltages as the relay resets. This
corresponds to the relay drop-off only if the voltages did not
reset timing is usually very short, so the voltage does not
change very much at release, and the measurement is
accurate.
. Now, repeat the procedure for V<. The starting voltage (pre-
fault and fault) will be less than VN (for instance, 90 V); the
threshold and drop-off for V< are found.
1.8.4. Angle threshold
We start from a situation where:

. Amplitudes are the same, and equal to VN;
. Phase is different: it can be more or less than zero; two
angle thresholds, A> and A<, will be found;
. Frequency is the same (the mains).
From this, we will modify the phase angle, until the relay trips:
this is the angle threshold. The test will be performed first with
A > 0°, and then with A < 0°.
. Press ON, and adjust V1 to VN.
. Press OFF, and adjust V2 to VN.
. Press ON, and adjust the phase angle of V2 with respect to
V1 at a value outside the permission (for instance, 45°):
voltage> (Value) (RET)
. Now, check that the relay is not tripped, and then slowly
reduce the phase angle until the relay trips: at this moment,
proceed: the high angle threshold A> is found.
. Next, we find the drop-off threshold for A>. From the angle
above, slowly increase it; as the relay resets, confirm save
Now, repeat the procedure for A<. The starting angle will be
less than 0° (for instance, 315°); the threshold and drop-off
for A< are found.
1.8.5. Frequency threshold

The frequency test is much more difficult, because any
frequency slip between two voltages, leads to a phase angle
shift between them. An example will better explain what
happens.
Let’s consider the first voltage V1 at FNOM: it could be
represented by a vector turning at 50 (6) rounds per second.
Consider now the second voltage V2 at 50.1 Hz: it could be
represented by a vector turning at 50.1 rounds per second.
This means that V2 turns slightly quicker than V1, so V1 sees

V2 turning at a frequency of F = 50.1-50 = 0.1Hz: 1 turn
every 10”. This means an angle variation of 360° / 10s =
36°/s.
If we have a relay where:
. Angle sector = ± 5°;
. Operating time: 0.1s,
the maximum frequency differential that allows the relay to
trip can be computed as follows.
. Total operating angle sector: 5+5=10°;
. Maximum angle ROC: 10°/0.1s = 100 °/s;
. Maximum frequency differential. Since 360°/s correspond to
1Hz, 100°/s ≡ 100°/360° = 0.278 Hz.
So, these parameters are related to each other.
This discussion leads also to the mode of performing the test:
. The voltages should be shifted by the maximum allowed
angle plus something, so that we start from the not
synchronized condition (in our instance, - 6° or + 6°);
. Start the test with the programmed frequency differential:
negative differential starting from the negative angle limit;
. The frequency limit is found by a series of tests with different
frequencies around the specified limit;
. The test will have a maximum time equal to a multiple of the
operating time (for instance, 2 times). However, for some
relay the enable is given only after a complete tour in the
enabled situation; in this instance, test time is computed as
follows:
(test time) = 1.1 * 1 /(FNOM – FTEST)
The fact that we have to start the test from the not
synchronized condition is critical, because:
. When we are OFF, voltage V1 is not applied;
. If we start the test by applying V1 that has a given phase
shift and frequency differential with respect to V2, the relay
could behave the wrong way. To avoid this, we take advantage
of the pre-fault duration selection, during which V1 and V2 at
nominal frequency, but with the programmed phase shift, for
time that allows the relay to reset; after this, test starts by
changing only the frequency of V2.
This explained, the test procedure is the following.

. Adjust the pre-fault amplitude of V2 to VN:
fault amplitude > (Value) (RET)
Pre-fault
duration > (TPF) ESC
. Press ON, and adjust: V1 to VN; the phase angle of V2 with
respect to V1 to the first angle (for instance, - 6°); the fault
frequency to the first test value:
voltage> (Value) (RET)
> Frequency > Adjust
> (FTEST) ESC
. Now, press ON+TIME and check if the relay trips.

- The relay trips: increase the frequency (with FTEST > FN) by
the desired accuracy, and repeat until the relay does not trip.
Program the last frequency when it tripped, start the test and
save the test result.
- The relay does not trip: decrease the frequency (with FTEST
> FN) by the desired accuracy, and repeat until the relay trips:
as it does, save the test result.
. The test is repeated with FTEST < FNOM.
The procedure gives also trip times.

1.9 TIMER TEST
It is possible to test timers by using the output (67). The test

is performed like the time delay test for current relays.
Connect the start of the timer to the normally open or

normally close contact of sockets (67), depending on the type
of timer under test. Connect the output of the timer to STOP
input sockets (65). Start the test pressing ON+TIME: the timer
will measure the time between the closing of the contact and
the intervention of the timer.
1.10 LOSS OF FIELD RELAY TESTING
The typical connection schematic is the following.
The relay monitors voltage and current outputs of the

protected generator, and whenever a fault condition is
detected, the relay will cause the switchgear to trip in order to
preserve the generator safety. When the generator looses the
rotoric magnetic field, the working point moves, in the plan R-
X, towards the X-axis.
Reactance
4
0 Resistance
-10 -8 -6 -4 -2 0 2 4 6 8 10
-4
-8 Relay Characteristic
Generator Working Point
-12
-16
-20
The relay detect the loss of field fault when the working point
enters the relay characteristic curve (the circle). The typical
parameters for LOF relays are the following.
K2 R
K1
K1 : circle diameter; expressed in % of ZN;

K2: offsert; expressed in % of ZN;
VN
ZN 
IN * 3
The characteristic curve depends upon: voltage; current;

phase angle between them. The test of the characteristic curve
is therefore performed by a number of threshold tests, where
each point is found by setting two parameters as fixed and
changing the third one. The selection of which parameter to
keep fixed and which one should be changed asks for some
more consideration.
Let’s start with the test of point A, that means to measure the
parameter K2. Finding it means to move from a point having
zero impedance and increasing the impedance along the –X
axis. As we have to generate voltage and current at a given
phase angle, the first step is to convert impedance into these
parameters. Steps to be followed are:
. Compute the impedance corresponding to K2 and K1. For
instance, if we have the following setting:
- VN = 100 V;
- IN = 5 A;
- ZN = 11.56 Ohm;
- K2 = 0,1;
- K1 = 1
Then:
ZA = 1.156 Ohm;
ZB = (K1+K2)*ZN = 12,72 Ohm.

. Choose the parameters corresponding to point A. As Z = V/I,
taking V as the reference, on the X axis the I angle is – 90°,
or 270° ; on the –X axis it is 90°. Now, as we want to move
from the point with 0 impedance down to A, it is apparent that
the test is best performed by setting a constant value for the
current, say IT, and modifying the voltage. The zero
impedance point corresponds to V = 0; the point A
corresponds to the voltage VA = ZA * IT.
In our instance, if we choose It = 5 A, then VA = 5.78 V. In
conclusion, the test of point A is conducted by:
- Setting the current at IT = 5 A;
- Setting the I angle at 90°;
- Increasing the voltage from 0 until the relay trips.
Next point to be tested is B: how will we perform the test? As

per point A, we can set the starting current at 5 A; but, what
about the starting voltage? As you can see in the diagram, you
have to start from a voltage VS that must be HIGHER than
VS = ZB * IT = 63.6 V,
Then DECREASE the voltage rather than increasing it, until the
relay trips. In our instance, starting from 80 V and decreasing
it would do.
Next, we want to test point C: how to do it? One could

compute the corresponding angle, and perform the test as per
A or B; however, minor errors in the angle would cause big
errors; C could also be missed. In this situation, the way is to
compute the current and voltage corresponding to ZC, and
modify the phase angle between them. In our instance:
ZC = ZA + (ZB-ZA)/2 = 6.94 Ohm;

IT = 5 A; VC = 34.68 V.
The test is performed applying these current and voltage at

the angle of 0°, and then increasing the angle until the relay
trips. Note that if you use the same current and voltage, start
from 180° and decrease the angle, you get the symmetric
point C’.
Last, what about testing other points, like D? You can either
set current and angle and decrease the voltage, or set current
and voltage and decrease the angle.
1.11 AUTOMATIC RECLOSER TESTING
1.11.1 Introduction
The purpose is to test the recloser device, that allows to

reduce the downtime caused by transient faults. The
protection device can be: overcurrent; earth directional,
distance. The recloser operation is to issue a close command
some time after the trip command. After the first close
command, the reclose typically checks if a new open command
is issued within a so-called reclaim time. Two possibilities:
. No trip command within the reclaim time: the reclose resets

its internal logic; any further fault starts a new sequence;
. Trip command within the reclaim time: the reclose issues a
new close command, possibly after a different delay; the
procedure continues until the maximum number N of close
commands has been reached, after which no further close
command is issued.
The goal of the test is to measure:

. Reclaim time TD;
. Reclose timings , that may be different during the test;
. Pre-set maximum number N of close commands;
. Verify that, if the fault occurs before TD expires, there is no
Reclose command after N faults.
The test is performed taking advantage of the features offered

by T1000 PLUS. Two test sequences are foreseen:
 Normal reclose test;
 Test of a pole mounted CB (that includes the reclose
device).
When you select the Reclose mode, the following screen is

opened.
Selection parameters are the following.

 TD (5 s default value): it is the reclaim time; see later
on.
 RECL NUM: it is the number of reclose commands that
the Recloser will issue before going to a reclose failed
status.
 RECL MEASURE FROM: Tof – Ton. The reclose delay can
be defined two different ways: from the Open
command falling edge (Tof); from the Open command

leading edge (Ton): see the following design.
FAULT
OPEN
CLOS
E
Tof
Ton
 ONE INPUT. If unchecked, we perform the test of a

normal Recloser; if checked, we perform the test of a
pole mounted CB.
 BREAKER SIMUL: if checked, during the test the
auxiliary relay simulates the CB position: this is often a
mandatory input to the Recloser.
1.11.2 Normal Recloser test
The following is the connection schematic for a normal

Recloser test.
CB Open - Closed
. The test is performed on the pair made of the relay and the
Recloser. All connections from the relay to the Recloser shall
be left. Nothing changes if the Recloser is inside the relay. The
relay can be of any type.
. Current and voltage outputs of T1000 PLUS will be connected

to the relay, according to the type of relay. The instructions for
the connection are given in the paragraph related to the relay.
. The relay trip command shall be connected to the STOP input
of T1000 PLUS.
. The Close command shall be connected to the START input
of T1000 PLUS.
. If necessary, connect the auxiliary relay output A1 to the CB
position Recloser inputs. The test starts with a Closed CB; at
the end of all tests, the test set comes back to the same
Closed position, to be ready for another test.
Connect the black socket of A1 to the polarizing voltage.
Before connecting the NO or NC contact of A1, verify the signal
logic: if Closed is No voltage, then connect to the NO socket;
else, connect to the NC socket.

(23). Connect the DC supply input of the relay and Recloser to
sockets (63).
The test set measures:

. All trip delays D1, D2… of the sequence;
. All reclose delays R1, R2… of the sequence: they are
measured from the trip command leading or falling edge,
according to the selection;
. We don’t know the nominal close delays R1, R2,..: they can
be different during the test (for instance: fast reclose, slow
reclose, neutralization). In order to avoid stopping the test
before its completion, the logic is the following one:
.. If N > 1, after the first Close delay, the test set waits 99999
s for the next close command;
.. If N > 2, after the second Close delay, the test set waits for
a time equal to the former close delay, multiplied by 10.
. After a Close command, the test set generates a new fault
after a delay equal to TD, until N+1 tests are performed;
. After the last fault, the test set waits until it is sure that no
reclose command arrives.
. The test ends after N+1 faults have been generated.
However, the fact that actually the recloser will operate N+1
times depends upon the programmed value for the reclaim

time TD:
.. If the programmed value is more than the recloser setting,
then the test set will generate N+1 faults, followed by N+1
fast Close commands (because they are all new faults);
.. If the programmed value is less than the recloser setting,
then the test set will generate N+1 faults, followed by N Close
commands of different delays (because they are all the same
fault), and there will be no Close command after fault N+1.
The reclaim time test, that is the test that the reclaim time is
correctly set, cannot be performed directly, because the
Recloser does not have an auxiliary output that trips as it
expires. For this reason, the reclaim time is tested with two
test sequences, as follows.
. First test: TD is programmed greater than the Recloser’s

reclaim time TDr, for instance TD = 1.05*TDr. Program the
number of tests N foreseen by the Recloser. As the fault
arrives after the reclaim time is expired, the Recloser must
always issue the close command, also after N+1 faults; there
is no evolution in the time delay. This behavior confirms that
faults occur after TDr has expired. The following time diagram
explains the test evolution.
FAULT 1 2 N+1
TRIP 1 2 N+1
CLOSE 1 2 N+1
CLOSED
CB POS
OPEN
D1 R1 >TDr
The first fault starts the sequence. The relay trips after D1;
the Recloser sends a reclose command after R1. The test set
automatically injects fault No. 2 after the programmed TD,
that is more than TDr: the Recloser sends the reclose
command No. 2. If N = 1, the sequence is completed; else,
tests will continue until fault N+1 is generated, followed by

open N+1 and reclose N+1.
. Second test: TD is programmed smaller than the set

reclaim TDr, for instance 0.95*TDr. Program the number of
tests N foreseen by the Recloser. As the fault arrives before
the reclaim time is expired, after N+1 faults the Recloser must
not issue the close command. This behavior confirms that
faults occur before TDr has expired. The following time
diagram explains the test evolution.
The second test allows also to verify the reclose timings RX,
and the number of reclose commands, N.
1 2 N+1
TRIP 1 2 N+1
CLOSE 1 2 (N+1
)
CLOSED
CB POS
OPEN
D1 R1 <TDr
the Recloser sends a reclose command after R1. The test set
automatically injects fault No. 2 after the programmed TD,
that is less than TDr. If N = 1, the sequence is completed;
else, tests will continue until fault N+1 is generated, followed
by open N+1, but no reclose N+1; the CB will be left open.
The test set waits for the last close command for a time equal
to 10 times the last measured RX delay; then, the sequence is
finished.
The two tests together allow verifying TDr with the set
accuracy (for instance, 5%).
1.11.3 Normal recloser test programming
First of all, press ON and pre-set current (and voltage) values

such that the relay trips. Note that after this operation it is
necessary to reset the internal memory of the Recloser: this is
achieved by removing for a short time the auxiliary supply.
Next, set the fault injection as Maintained. Note that test

duration is N times the reclose delay, that can be in the range
of minutes, plus the wait time for the last reclose that should
not arrive, that is 10 times the last measured reclose delay.
This makes the test time rather long: if TD is three minutes,
test duration is more than 30 minutes.
TEST CONTROL > Fault injection > Maintained ESC
Next, select the Recloser test on the main menu as follows:

 TD: on the first test, 1.05* TDr; on the second one,
0.95*TDr;
 RECL NUMBER = N;
 RECLOSER DELAY MEASURE FROM Tof or Ton,
according to the Recloser delay definition;
 One input: unchecked;
 Breaker simulation: checked.
Next, select the save as Automatic at trip:
TEST CONTROL > Save > Automatic at trip ESC
Note that the test set will produce N+1 test result pairs,
grouped in pairs on the bottom left of the display.
Start the test with ON+TIME. For each fault X, the display
shows on one line two test results: to the right, the relay trip
delay; to the left, the reclose delay. Test result time are four
digits with autoranging, so that the percent accuracy is the
same for fast and slow reclose times. It is possible to monitor
the test evolution looking at these times, and also at the STOP
and START lights ; the TRIP light follows the relay trip.
For the first test sequence, all tests will have two meaningful
timings ; for the second one, after the last test, the START
light will not turn on : this confirms that the Recloser has
expired all the programmed reclose attempts.
In all instances, as the test is over, the ON+TIME light turns
off, the test set goes to OFF, and the display shows the
message of results recording.
Remember that, if N is the programmed number of Reclose

commands, at the end of the test there will be N+1 results in
memory.
For the second test sequence, the last time result will be 0 s,
confirming that there was no trip within 10 times the last
measured reclose delay.
NOTE: if it is wished to avoid waiting this time, which can be

very long, select OFF to stop the test: test results will be
saved anyway, and the last delay, no trip, will be displayed as
0.000.
1.11.4 Pole mounted CB test
The following is the connection schematic for this situation.
I POLE
MOUNTED CB
CB POSITION
. The test is performed connecting the T1000 current output

(typically, the high current output) to the CB, that
incorporates the Recloser, and the CB position output contact
to the STOP input.
The test set measures:

. All trip delays D1, D2… of the sequence;
. All reclose delays R1, R2… of the sequence: they are
measured from the trip command leading or falling edge,
according to the selection;
. We don’t know the nominal close delays R1, R2,..: they can
be different during the test (for instance: fast reclose, slow
reclose, neutralization). In order to avoid stopping the test
before its completion, the logic is the following one:
.. If N > 1, after the first Close delay, the test set waits 99999
s for the next close command;
.. If N > 2, after the second Close delay, the test set waits for
a time equal to the former close delay, multiplied by 10.
. After a Close command, the test set generates a new fault

after a delay equal to TD, until N+1 tests are performed;
. After the last fault, the test set waits until it is sure that no
reclose command arrives.
. The test ends after N+1 faults have been generated.
However, the fact that actually the recloser will operate N+1
times depends upon the programmed value for the reclaim
time TD:
.. If the programmed value is more than the recloser setting,
then the test set will generate N+1 faults, followed by N+1
fast Close commands (because they are all new faults);
.. If the programmed value is less than the recloser setting,
then the test set will generate N+1 faults, followed by N Close
commands of different delays (because they are all the same
fault), and there will be no Close command after fault N+1.
The reclaim time test, that is the test that the reclaim time is
correctly set, cannot be performed directly, because the
Recloser does not have an auxiliary output that trips as it
expires. For this reason, the reclaim time is tested with two
test sequences, as follows.
. First test: TD is programmed greater than the Recloser’s

reclaim time TDr, for instance TD = 1.05*TDr. Program the
number of tests N foreseen by the CB’s Recloser. As the fault
arrives after the reclaim time is expired, the CB must always
close, even after N+1 faults; there is no evolution in the time
delay. This behavior confirms that faults occur after TDr has
expired. The following time diagram explains the test
evolution.
FAULT 1 2 N+1
CLOSED
CB POS
OPEN
D1 R1 >TDr
The first fault starts the sequence. The CB opens after D1, and
then closes after R1. The test set automatically injects fault
No. 2 after the programmed TD, that is more than TDr: the CB
opens and closes again. If N = 1, the sequence is completed;
else, tests will continue until fault N+1 is generated, followed
by open N+1 and reclose N+1.
. Second test: TD is programmed smaller than the set

reclaim TDr, for instance 0.95*TDr. Program the number of
tests N foreseen by the CB’s Recloser. As the fault arrives
before the reclaim time is expired, after N+1 faults, the CB
must not close. This behavior confirms that faults occur before
TDr has expired. The following time diagram explains the test
evolution.
The second test allows also to verify the reclose timings RX,
and the number of reclose commands, N.
FAULT 1 2 N+1
CLOSED
CB POS
OPEN
D1 R1 >TDr
the CB closes after R1. The test set automatically injects fault
No. 2 after the programmed TD, that is less than TDr. If N =
1, the sequence is completed; else, tests will continue until
fault N+1 is generated, followed by open N+1, but no close
N+1; the CB will remain open.
The test set waits for the last close for a time equal to 10
times the last measured RX delay; then, the sequence is
finished.
The two tests together allow verifying TDr with the set
accuracy (for instance, 5%).
1.11.5 Pole mounted CB test programming
First of all, press ON and pre-set current (and voltage) values

such that the CB trips. Note that after this operation it is
necessary to wait until the internal memory of the Recloser
resets.
Next, set the fault injection as Maintained. Note that test

duration is N times the reclose delay, that can be in the range
of minutes, plus the wait time for the last reclose that should
not arrive, that is 10 times the last measured reclose delay.
This makes the test time rather long: if TD is three minutes,
test duration is more than 30 minutes.
TEST CONTROL > Fault injection > Maintained ESC
Next, select the Recloser test on the main menu as follows:

 TD: on the first test, 1.05* TDr; on the second one,
0.95*TDr;
 RECL NUMBER = N;
 RECLOSER DELAY MEASURE FROM Ton;
 One input: checked;
 Breaker simulation: unchecked.
Next, select the save as Automatic at trip:
TEST CONTROL > Save > Automatic at trip ESC
Note that the test set will produce N+1 test result pairs.
Start the test with ON+TIME. For each fault X, the display
shows on one line two test results: to the right, the relay trip
delay; to the left, the reclose delay. Test result times are four
digits with autoranging, so that the percent accuracy is the

same for fast and slow reclose times. It is possible to monitor
the test evolution looking at these times, and also at the STOP
light.
For the first test sequence, all tests will have two meaningful
timings ; for the second one, after the last test, the START
light will not turn on: this confirms that the CB has not closed.
In all instances, as the test is over, the ON+TIME light turns
off, the test set goes to OFF, and the display shows the
message of results recording.
For the second test sequence, the last time result will be 0 s,
confirming that there was no trip within 10 times the last
measured reclose delay.
NOTE: if it is wished to avoid waiting this time, which can be
very long, select OFF to stop the test: test results will be
saved anyway, and the last delay, no trip, will be displayed as
0.000.
1.12 DISTANCE RELAY TESTING
1.12.1 Introduction
The test of distance relays is possible only with three T1000

PLUS, taking advantage of the EXTERNAL test start feature.
The test of distance relays can be performed the following

ways:
. With a three phase supply, it is possible to simulate single
phase, phase to phase or three phase faults.
. With single phase supply, single phase or phase to phase
faults can be simulated.
There are two difficulties to perform distance relay testing:

. It is necessary to compute the fault value; from test result, it
is necessary to compute back the corresponding fault
impedance. This task is easy with single phase and three
phase fault; a bit cumbersome with phase to phase faults.
. Currents are in phase with the power supply. This means that
it is necessary to choose the proper T1000 PLUS power supply
connection as a function of the type of power supply (single
phase or three phase), and to compute voltage phase angles
accordingly.
Last, it is necessary to understand very clearly what we mean

when we say “test the setting”.
First of all, let us consider a possible characteristic of the

distance relay to be tested, that is designed in the R-X plane.
There are very many different shapes, but the shape does not
affect the testing.
Z3
Z2
Z1
The first decision for the operator is to select the angle at

which he wants to perform the test. It can be that purpose of
the test is to check a limited number of settings; if so, they
are typically given at the line angle (usually 75° to 85°), and
possibly also at 0° and 90°. Please note that this angle is the
Φ(I-V) angle to be used during the test, but WITH NEGATIVE
SIGN: the reason is that
Z=V/I
As the current is at the denominator, the angle sign is

changed.
Now it must be understood that once the angle is selected, the

phase angle line intercepts the characteristic at the setting
values; this is represented in the Z-t plane by the following
curve.
During our tests, we do not modify the test angle and the test
current: as a consequence, the fault impedance becomes a
function of the test voltage only. Now, the point is that a
setting of nominal value Z is verified when we find that:
. With a fault at Z-d the relay trips in zone N;
. With a fault at Z+d the relay trips in zone N+1.
The value d can be made as small as desired; however, ad d is

smaller, the step between zones becomes uncertain, and not
exactly steep. If the above is verified, then the relay setting is
Z. In conclusion, you always need two tests to verify the
setting; you cannot compute the values corresponding to Z,
start one test and decide if the setting is correct. This makes
the testing more difficult, especially with phase to phase
faults.
As example, Z1 is checked when:

. With Z1-d, the relay trips with delay T1;
. With Z1+d, the relay trips with delay T2.
In a similar way, time limits for Z2 are T2 and T3, and for Z3
are T3 and no trip.
As you see, testing distance relays can be difficult; however, it

can be very important to be able to do it anyway.
1.12.2 Definition of terms

The definition of parameters is the following.
. VN = Nominal relay phase voltage: it is the nominal voltage

V divided by 1.73. For V = 100 V, then VN = 57,8 V; for V
= 110 V, VN = 62,5 V.
. IN = nominal relay current; usually, 5 A or 1 A.
. Z = fault impedance, on the secondary side.
. KoL = zero-sequence coefficient; it is a number; usually it
ranges between 0.5 and 2.
. If = fault current. The fault current If shall be greater than
the zero voltage starting current IV0, and less than IMAX,
that is computed as a function of the maximum fault
impedance to be simulated ZM, as follows:
Single phase faults: IMAX = VN / (ZM * (1 + KoL))
Phase to phase faults: IMAX = VN / (2 * ZM)
Three phase faults: IMAX = VN / ZM
If the test current is greater than IMAX, the last setting
cannot be found. Usually its value is chosen between 5 and
10 A (for IN = 5 A), or from 1 to 2 A (for IN = 1 A).
. Vf = fault voltage; it is computed as a function of Z and the
other parameters.
. Φ(I-V) = angle of the fault current with respect to the fault
voltage, taken as the reference. Typically, tests are
performed with Φ(I-V) ranging from 0° to 90°.
1.12.3. Relay connection

The first thing is to connect the three T1000 PLUS to the relay
to be tested. The connection depends upon the type of test:
single phase, phase to phase; three phase. The phase angle of
voltages will change as a function of the type of test, and also
as a function of power supply available: single phase or three
phases. The following table summarizes power supply
connections.
FAULT SUPPLY VS1 VN1 VS2 VN2 VS3 VN3

SINGLE 3 PH V1 VN V2 VN V3 VN
1 PH V1 VN V1 VN V1 VN
THREE 3 PH V1 VN V2 VN V3 VN
PH 1-2 3 PH V1 VN VN V1 V3 VN
PH 2-3 3 PH V1 VN V2 VN VN V2
PH 3-1 3 PH VN V3 V2 VN V3 VN
PH 1-2 1 PH V1 VN VN V1 V1 VN
PH 2-3 1 PH V1 VN V1 VN VN V1
PH 3-1 1 PH VN V1 V1 VN V1 VN
Note: in phase to phase faults, currents are equal in module

and opposite in phase.
CONNECTION OF THREE T1000 PLUS TO THE DISTANCE RELAY

The last problem is that there is no special mark on the power

supply cord that tells the phase supply apart from the neutral
supply. In order to be sure about power supply connection, it
is necessary to meter the phase angle between main voltage
outputs, which are in phase with the power supply. The
procedure is the following.
. Connect the three T1000 PLUS to the mains as per the above
schematic.
. Connect the main voltage output of T1000 PLUS-2 to the
external measurement input of T1000 PLUS-1.
. On T1000 PLUS-1 select the external measurement.
. On both T1000 PLUS, select the main voltage output
measurement.
. Press ON on both T1000 PLUS, and adjust the main voltage
output to 100 V.
. Check that the displayed angle is the following one; if not,
reverse the supply of T1000 PLUS-2.
. Repeat the sequence with T1000 PLUS-3.
FAULT SUPPLY T1000 T1000

PLUS-2 PLUS-3
SINGLE 3 PH 240° 120°
1 PH 0° 0°
THREE 3 PH 240° 120°
PH 1-2 3 PH 180° 120°
PH 2-3 3 PH 240° 60°
PH 3-1 3 PH 60° 180°
PH 1-2 1 PH 180° 0°
PH 2-3 1 PH 0° 180°
PH 3-1 1 PH 180° 180°
1.12.4 Test conduction
Of the three T1000 PLUS, we will consider the one connected

to phase 1 as the “Master”: it drives the test of all T1000 PLUS
as follows.
The test is performed taking advantage of the External

selection on Fault injection: in this mode, fault generation and
time measurement are performed only when the START input
is sensed. The reason why we define T1000 PLUS-1 as the
“master” is because it is its auxiliary contact that starts the

test of all T1000 PLUS, including itself. In conclusion, the test
sequence will be the following:
. Select the External mode on all T1000 PLUS:
TEST CONTROL > Fault injection > External ESC
. Program the auxiliary contact closure on T1000 PLUS-1:
TEST CONTROL > Auxiliary contact (delay = 0) ESC
. Press ON+TIME on T1000 PLUS no. 2 and 3: no output is
generated; timer does not start;
. Press ON+TIME on T1000 PLUS-1: outputs are generated
and timers start on all T1000 PLUS.
. This sequence is to be followed whenever a fault is
generated.
The other selection to perform on all T1000 PLUS is the pre-

fault range and mode:
AUX VAC/VDC > Aux VAC control > Range RET
> Mode > Pre-fault +
fault > Pre-fault amplitude
> Pre-fault phase
Set the range at the value closer to VN: usually it is 62.5 V.

The pre-fault amplitude value is VN.
For single phase and three phase faults the pre-fault phase is
zero; for phase to phase faults see below.
1.12.5 Single phase fault
In single phase faults, voltage and current vectors are

modified during the test as shown in the following figure.
V R N
V 
R
I R
V T
V S
This instance applies to phase 1 fault: as test starts, the value

of V1 goes from VN to Vf; at the meantime, If is applied, at
the pre-set phase angle.
1) Fault current
The current will be adjusted only on the faulty phase (1, 2

or 3), while the others remain at zero; its value is the one
selected by the operator (for instance, 10 A).
2) Healthy voltages phase angles
Choose the test angle in the R-X plane. If the distance relay is
set on the CT star point towards Busbar, the angle Φ(I-V) has
the same value but negative, otherwise it has the same value.
These angles depend upon the test angle and the supply: see
the table below. The angle is adjusted prior to actual zone
testing, as follows.
Start the test; adjust the fault current; adjust the fault voltage
at 30 V. Now select the auxiliary Vac phase with respect to the
current, as follows:
AUX VAC/DC > Aux Vac control > Phase > Reference:
current ESC
This adjustment will not be modified during tests.
SUPPLY FAULT PHASE 1 PHASE 2 PHASE 3

3 PHASE ANY Φ(I-V) Φ(I-V) Φ(I-V)
1 PHASE PHASE 1 Φ(I-V) Φ(I-V) + Φ(I-V) +
240° 120°
PHASE 2 Φ(I-V) + Φ(I-V) Φ(I-V) +
120° 240°
PHASE 3 Φ(I-V) + Φ(I-V) + Φ(I-V)
240° 120°
3) Zone limits test
Given the fault impedances Z1, Z2, Z3, Z4 of the zone limits,
compute as follows the corresponding fault voltages V1, V2,
V3, V4:
Vf = Z*If*(1+KoL)
For instance: KoL = 1; If = 10 A

Vf = 20 * Z
These voltages are the limits between following zones, as

follows:
VOLTAGE < > < > < > < > V4

V1 V1 V2 V2 V3 V3 V4
TIMING T1 T2 T2 T3 T3 T4 T4 NO
TRIP
ZONE 1 2 3 STARTER
LIMIT
Where: T1, T2, T3, T4 are respectively the time settings for
zones 1, 2, 3, 4 (case of three zones plus the starter).
Once fault current and pre-fault voltage amplitudes have been

adjusted to VN, stop the test and start again. Adjust the fault
voltage of the selected phase at a value slightly less than V1,
VT11: the trip time should be the one of zone 1. Slightly
increase the fault voltage and start again with value VT12: trip
time should become T2. The procedure can be repeated at
will, until the first zone is checked with the desired accuracy:
the result is
Z1 = (VT11+VT12)/(2*If*(1+KoL))
Once a limit has been found, repeat the test for other zone
limits. During these tests, current and phase are no more
modified.
Example. Let us assume that the distance relay to be tested

has the following settings at line angle (75°).
ZONE LIMIT ONE TWO THREE

IMPEDANCE Ohm 0.2 0.4 1
TIMING 0.05 0.3 0.6
s
Let us assume: KoL = 1; IV0 = 2.5 A; VN = 57.8 V (100 V).

Maximum test current is:
IMAX = 57.8/(2*(1+1)) = 14.4 A.
We choose If = 8 A; the corresponding zone limit voltages are:

V1 = 3.2 V;
V2 = 6.4 V;
V3 = 16 V;
VSTART = 32 V.
We adjust the current of I1 to 8 A; the V-I phase angle is -75°

(line side) or 105° (Busbar side); V1 fault voltage is 3.2 V; V2
and V3 are 57.8 V.
We start the test at 3 V; if trip time is 0.05 s we slightly
increase V1 and start again, until trip time becomes 0.3 s: let
us assume that VT11 is 3.5 V and VT12 is 3.6 V. This means
that first zone limit is 0.221 Ohm; the error is + 10%.
If instead with 3 V the trip time is 0.3 s we reduce V1 and
start again, until trip time becomes 0.05 s: let us assume that
VT11 is 2.9 V and VT12 is 3 V. This means that first zone limit
is 0.185 Ohm; the error is -7.4%.
The test continues with the following fault voltages, until all
limits are tested. The starter limit is found between 1.2 s trip
time and no trip. This limit can also be found starting the test
with V1=VN, and then lowering V1 until the relay trips.
If the starter is over-current, and it is desired to find threshold
settings IVN and IVo, the test is performed as a time
independent over-current relay, but test voltage will be 0 V for
the test of IVo, and VN for the test of IVN.
The test can continue as follows:

. Test the same settings, with faults on phases 2 and 3;
. Test other types of fault.
1.12.6 Phase to phase fault
In phase to phase faults, voltage and current vectors are

modified during the test as shown in the following figure,
which refers to the fault of phases 2 and 3.
Note that in this type of fault the fault voltage is the phase to
phase voltage; fault currents are identical in module and
opposite in phase; the fault current angle is metered with
respect to the phase to phase voltage.
This situation makes the test of phase to phase faults quite

cumbersome. For each test, it should be necessary to modify
the fault voltage amplitude and phase. However, it is possible
to test phase to phase faults by modifying the fault voltage

amplitudes only, provided that the zone limit is very close to
the nominal setting, and amplitude changes do not exceed
5%: if they are more, also phase angles must be computed
and changed.
Other important note is that fault amplitudes of the two

phases should be adjusted to the same value: different values
cause a phase error between the phase to phase voltage and
the fault current. This is particularly true when the phase to
phase voltage tends to zero: in this situation, minor amplitude
errors cause the complete loss of control on fault angle. For
these reasons, it is not advisable to perform phase to
phase fault tests unless with fault voltages of 5 V or
more. In general, it is advisable to use the third generator,
the one not involved in the fault, to measure the phase to
phase fault voltage.
Last but not least, the phase arrangement of fault voltages is

not the same as pre-fault voltages. This means that we have
to compute the voltage to current fault angle, and the angle
between pre-fault voltage and fault voltage.
In conclusion, given the fault impedance Z and the test angle

φ, we have to perform the following steps:
. Select the fault current If;

. Compute the fault voltage Vf (it is the phase to phase
voltage!);
. Compute the module of phase fault voltage VX;
. For both phases, compute the angle φX of the fault voltage
with respect to the fault current (that is in phase with the
power supply);
. For both phases, compute the angle of the healthy voltage
with respect to the power supply.
1) Fault current
The current will be adjusted on the two faulty phases (1

and 2; 2 and 3; 3 and 1), while the other remains at zero; its
value is the one selected by the operator (for instance, 10 A).
2) Phase to phase fault voltage
The phase to phase voltage is:

Vf = Z*If*2
For instance: If = 10 A
Vf = 20 * Z; with Z = 1 Ohm, Vf = 20 V.
3) Phase fault voltage
For both faulty phases, the phase fault voltage is:
VX = 0.5* sqrt(VN^2 + Vf^2)
For instance, if Z = 1 Ohm; If = 10 A; Vf = 20 V; VN = 57.8

V,
VX = 30.58 V
The third phase does not change its amplitude, equal to VN.
4) Phase angle
We will compute first of all the angle of fault voltage with

respect to the voltage when the fault amplitude is zero, φX1,
that is:
φX1 = atg(Vf/VN)
φX1
V2 V3
Vf V’3
Given this angle, the following table summarizes the pre-fault

angle and the fault angle for all types of test.
FAULT 1-2 2-3 3-1

FAULT V1 30°-φ 0° -30° -

ANGLE φ
V2 -30° -φ 30°-φ 0°
V3 0° -30° -φ 30°-φ
PRE-FAULT V1 - (60° - 0° 60° -
ANGLE φX1) φX1
V2 60° - φX1 - (60° - φX1) 0°
V3 0° 60° - φX1 - (60°
-
φX1)
In our instance, φX1 is 19°; if φ = 75°, phase angles to be

programmed are the followings.
FAULT 1-2 2-3 3-1

FAULT V1 -45° 0° -105°
ANGLE V2 -105° -45° 0°
V3 0° -105° -45°
PRE-FAULT V1 - 41° 0° 41°
ANGLE V2 41° - 41° 0°
V3 0° 41° - 41°
These values apply for the test of the zone having the
impedance of 1 Ohm ; for other zones they should be
repeated.
This made clear, the other thing to make clear is how to

perform the test. Once all values are correctly programmed
and adjusted, start the test: the relay will trip in zone N or in
zone N+1. To check the setting, in the first case you need to
increase Vf until the relay trips in zone N+1; in the second
case you should decrease Vf until the relay trips in zone N.
Once this is obtained, the zone setting is computed based
upon the average of two Vf voltages that make the relay to
trip in the different zones, Vf1 and Vf2:
Z = (Vf1 + Vf2) / (4 * If)

The approximation is that we change only fault voltages and

not the corresponding angle: the drawing explains the
approximation.
Vf1
V2 V’2 V3
Vf2 V’3
If the fault voltage needs to be increased more than 5%; else,

also phase angles must be computed and changed.
In our example, at first test the relay trips in zone N, with Vf =

20 V; on next test (higher voltage) the relay trips in zone
N+1, with Vf = 20.5 V; then:
Z = (20 + 20.5) / (4 * 10) = 1.012 Ohm.
1.12.7 Three phase fault
In single phase faults, voltage and current vectors are

modified during the test as shown in the following figure.
V R N
V
I
T
R
 I
R
V T V S
V T N I S
V S N
As test starts, all voltages are modified from VN to Vf; the

three fault current should be injected at the same time. This is
not completely true with the three T1000 PLUS because of the
zero crossing feature: the three phases have zero crossings
that are time shifted by 6.66 ms. The following figure explains
the situation; this means that in first zone the trip time will be
increased by 13,3 ms.
PHASE 1
PHASE 2
PHASE 3
6.66 ms
1) Fault current
The current will be adjusted on all the faulty phases; its

value is the one selected by the operator (for instance, 10 A).
2) Healthy voltages phase angles
Choose the test angle in the R-X plane. If the distance relay is
set on the CT star point towards Busbar, the angle Φ(I-V) has
the same value but negative, otherwise it has the same value.
These angles are adjusted prior to actual zone testing, as
follows.
Start the test; adjust the fault current; adjust the fault voltage
at 30 V. Now select on all T1000 PLUS the auxiliary Vac phase
with respect to the current, as follows:
AUX VAC/DC > Aux Vac control > Phase > Reference:
current ESC
This adjustment will not be modified during tests.
3) Zone limits test
Given the fault impedances Z1, Z2, Z3, Z4 of the zone limits,
compute as follows the corresponding fault voltages V1, V2,
V3, V4:
Vf = Z*If
For instance: If = 10 A
Vf = 10 * Z
These voltages are the limits between following zones, as with

the other faults.
Once fault current and pre-fault voltage amplitudes have been

adjusted to VN, stop the test and start again. Adjust all fault
voltages at a value slightly less than V1, VT31: the trip time
should be the one of zone 1. Slightly increase the fault
voltages and start again with value VT32: trip time should
become T2. The procedure can be repeated at will, until the
first zone is checked with the desired accuracy: the result is
Z1 = (VT31+VT32)/(2*If)
Once a limit has been found, repeat the test for other zone
limits. During these tests, current and phase are no more
modified.
Example. Let us assume that the distance relay to be tested

has the following settings at line angle (75°).
ZONE LIMIT ONE TWO THREE STARTER

IMPEDANCE 0.2 0.4 1 2
Ohm
TIMING 0.05 0.3 0.6 1.2
s
Let us assume: IV0 = 2.5 A; VN = 57.8 V (100 V). Maximum

test current is:
IMAX = 57.8/2 = 28.9 A.

We choose If = 8 A; the corresponding zone limit voltages are:

V1 = 1.6 V;
V2 = 3.2 V;
V3 = 8 V;
VSTART = 16 V.
We adjust all currents to 8 A; the V-I phase angle is -75° (line

side) or 105° (Busbar side); fault voltages are 1.6 V.
We start the test at 1.5 V; if trip time is 0.05 s we slightly
increase all voltages and start again, until trip time becomes
0.3 s: let us assume that VT31 is 1.55 V and VT32 is 1.65 V.
This means that first zone limit is 0.2 Ohm; the error is zero.
If instead with 1.5 V the trip time is 0.3 s we reduce all
voltages and start again, until trip time becomes 0.05 s: let us
assume that VT31 is 1.4 V and VT32 is 1.5 V. This means that
first zone limit is 0.181 Ohm; the error is -9%.
The test continues with the following fault voltages, until all
limits are tested.
1.13 TEST OF CONVERTERS
There are many types of converters: current; voltage; power;

power factor; frequency. The most common converter has a
DC current output; the amount of current is proportional to
the parameter, given the conversion factor. For many of these
converters, the zero value corresponds to 4 mA; this value
must be subtracted to the measured one prior to convert it
into the measured parameter.
The following connection scheme shows the connection of

current, AC voltage, DC voltage to the converter, and the
connection of the converter output to the low range DC current
measurement input of T1000 PLUS. This scheme applies to
converters having a conversion error of 2% up. For more
accurate tests, you need a reference converter. In this
instance, connect both converters (currents in series; voltages
in parallel), and measure the error between the current of the
converter under test and the reference converter.
The test procedure is simple:

. Firs of all, supply the converter and measure the zero input
current (nominally 4 mA).
. Next, select values to be generated; compute the
corresponding current measurement, and prepare a calibration
table.
. Next, generate the selected parameters, measure the
reading, report it to the table and compute the converter
error.
For instance, you want to test a current converter with the

following characteristic:
I0 = 4 mA; I100 = 20 mA.
From this, the nominal output current as a function of the

input current is:
Iout = 4 + Iin * (20-4)/100 = 4 + 0.16 * Iin

You can prepare the following table:
TEST NOMINAL ACTUAL ERROR

CURRENT MEAS. MEAS. %
A mA mA
0 4
10 5.6
20 7.2
50 12
100 20
1.14 TEST OF ENERGY METERS
Energy meters can be single phase or three phase; in the

second case, with three or two equipments. As T1000 PLUS is
a single phase generator, it is possible to test single phase
meters, or three phase with three or two equipments,
provided that voltages are connected in parallel and currents
in series.
The following connection scheme shows the connection of

current, AC voltage, DC voltage to the energy meter under
test, and also to a sample meter. This scheme applies to all
classes of energy meters, the accuracy range being given by
the sample meter. For less accurate tests, class 2 or more, it
is possible to avoid the use of the sample meter.
Each meter has its conversion constant, say Ks and Kt

respectively for the sample meter (Ks) and for the meter
under test (Kt). To perform the test:
. Place a suitable sensor in front of the LED (or rotating disk)
of the meter under test, and connect its output to the STOP
input. If the meter outputs a voltage impulse or a relay
contact the sensor is not necessary.
. Define the nominal test energy EN.
. Select the desired test voltage, current and phase angle, V, I
and angle (power factor).
. Define the nominal test time, TN = EN / (V*I*pf): it
should be large enough to avoid that time measurements error
influence the test result (more than 10 s).
. Define the corresponding number of impulses N = EN / Ks.
. Press ON and adjust current, voltage, angle to the desired
values. Press OFF.
. Select on T1000 PLUS the COUNT mode; program a number
of impulses equal to N:
TIMER START/STOP > Stop > Count (N) ESC
. Select the measurement of the generated energy:
METERS > Other internal > Ea – Er ESC
. Read on the sample meter counter the starting number of
impulses, N1.
. Press ON+TIME: current and voltage are applied until N+1
complete inputs are detected; at that moment, current
generation ends and the corresponding time is displayed. The
energy applied to both meters is taken from the sample meter,
reading the number of impulses after the test, N2. The applied
energy is:
Es = (N2 – N1) * Ks.
The energy Et measured by the meter under test is read on
the display. The error of the meter under test is
E% = (Et – Es) * 100 / Es
If the sample meter is not available, the test is performed

as follows.
. Place a suitable sensor in front of the LED (or rotating disk)
of the meter under test, and connect its output to the STOP
input. If the meter outputs a voltage impulse or a relay
contact the sensor is not necessary.
. Define the nominal test energy EN.
. Select the desired test voltage, current and phase angle, V, I
and angle (power factor).
. Define the nominal test time, TN = EN / (V*I*pf): it
should be large enough to avoid that time measurements error
influence the test result (more than 10 s).
. Define the corresponding number of impulses N = EN / Ks.
. Press ON and adjust current, voltage, angle to the desired
values. Press OFF.
. Select on T1000 PLUS the COUNT mode; program a number
of impulses equal to N:
TIMER START/STOP > Stop > Count (N) ESC
. Select the measurement of the generated energy:
METERS > Other internal > Ea – Er ESC
. Press ON+TIME: current and voltage are applied until N+1
complete inputs are detected; at that moment, current
generation ends and the corresponding time is displayed. The
energy applied to the energy meter under test, Es, is read on
the T1000 PLUS display.
The energy measured by the meter under test is computed as
follows:
Et = N * Kt
The error of the meter under test is:
E% = (Et – Es) * 100 / Es
NOTE. If it is desired to wait some turn prior to start the

energy measurement, it is possible to connect the impulse
input to both START and STOP input. Then, on START select
COUNT and program the number of turns before the
measurement; on STOP program COUNT and the number of
test turns N.
NOTE. The test is eased taking advantage of the optional SHA

2003 reading head and support. In this case, the option should
be located in front of the meter under test, as shown in the
following picture.
ADJUSTMENT
KNOB
DISK OR
LED SWITCH LED TURNS ON
PRESSED = AS THE MARK
DISK IS DETECTED.
The reading head can be used for rotating disk meters, and for
meters with an LED signaling light.
For rotating disk meters, power-on the head, and press the
Disk or LED Switch to the left. Then, mount the scanning head
so that the green light is lighting the rotating disk.
Next, start the Energy Meter program, select the Manual test
to feed the meter, and move the adjustment knob so that the
LED on the head front blinks as the mark is passing below the
head: the clockwise knob rotation increases the detector
sensitivity. You are now ready to perform the desired test.
For LED meters, first of all, the light can be red, but not green
or blue.
Power-on the head, and press the Disk or LED Switch to the
left. Then, mount the scanning head so that the green light
from the the head is lighting the meter’s LED; then, release
the Disk or LED Switch: the light is removed.
Next, press ON, so that the energy meter turns, and move the
adjustment knob so that the LED on the head front blinks as
the meter’s LED is blinking: the clockwise knob rotation
increases the sensitivity. You are now ready to perform the
desired test.
1.15 TRANSFORMER DIFFERENTIAL RELAY TESTING WITH D1000

OR TD1000 PLUS
1.15.1 Introduction
This test is performed taking advantage of the option D1000

or of the model TD1000 PLUS, that allow performing the
following tests of differential relays:
 Characteristic curve test;
 Harmonic restraint.
Before proceeding with the test description, we give some

basic hints on differential transformer protections.
1.15.2 The transformer

 There are many ways for connecting the transformer
primary and secondary windings; they are classified as
vectorial group.
 IA is the primary current phase 1

 Ia is the secondary current phase 1
Depending on the connections of winding 1 and 2 and the

polarity, the vectorial groups are as follows:
 Yy0 – Yy6
 Dy1 – Dy5 – Dy7 – Dy11
 Yd1 – Yd5 – Yd7 – Yd11
 Dd0 – Dd2 – Dd4 – Dd6 – Dd8 – Dd10
CONNECTION DAB CONNECTION DAC

A perfect test would require the use of 6 output

currents; however, as T1000 PLUS + D1000 can
generate only two currents, and only in phase, only a
single phase test can be performed.
The setting of the differential relay is computed by computing

the transformer taps, that are the Ipu (per unit current) after
the CT on both HV and LV sides, when the transformer is at
full load. The transformer TAPs are calculated according to:
the nominal power Pn, the primary and secondary voltage V1n
and V2n, the CTRatio, and the nominal current In:
Pn
Tap1 
3 * V1 * CTR1 * I n
Pn
Tap2 
3 *V2 * CTR2 * I n
These values are the p.u. nominal current at relay level after
the CT. They are fundamental when calculating the test
currents to apply to the relay.
Pn
I1 
3 * V1
Pn
I2 
3 *V2
I1 I2
I "1  I "2 
CTR1 CTR2
1.15.3 The Restraint and the Differential current
We define IR as Restraint current and it is normally given as

the average between current I1 and I2, where:
 I1: transformer primary side pu current
 I2: transformer secondary side pu current
Depending on the relay manufacturer, the Restraint current is
calculated as:
 I R  I1  I 2 : this formula is used by Siemens relays
I1  I 2
 IR  : this is the standard formula
2
I1  I 2
 IR  : this is used by some of GE relays for three
3
windings transformer
 I R  I1  I 2 : this is used on Ret316 relays
The differential current is defined as: I d  I1  I 2

A typical nominal characteristic of a transformer differential

relay is displayed in the figure above.
Testing the relay means to check the characteristic curve.
1.15.4 Connection to the relay
First of all we have to determine the connection schematic.

Assumptions:
 Group: YY0
 Tap 1 = 1
 Tap 2 = 1
There is now some difference between testing with the

external TD1000 module or with the TD1000 model.
When using the external D1000 option, the connection is

as follows.
 T1000 PLUS generates the current I1, connected as

displayed above.
 D1000 generates the current I2.
 A1 is the internal measure of T1000 PLUS.
 A2 is the External measure of T1000 PLUS .
The test principle is that we apply the restraint current to two

inputs, primary and secondary, of one phase of the differential
relay, while we apply the differential current only to one side.

The connection scheme is the following.
The following is the D1000 front panel. There are two pairs of
sockets: IN and OUT. IN is to be connected to the VCAUX
output of T1000 PLUS; D1000 converts the voltage into
current, and generates the differential current, that is
measured prior to connection to the relay. So, when we say
that the differential current is to be adjusted, this means
adjusting the auxiliary voltage.
The direction of the current is indifferent: on one direction, ID

adds to IR; on the other one, it subtracts. With this
arrangement, the test result is quite accurate, as we measure
ID directly, rather than finding it from I1 – I2, as this implies
being sensitive to the measurement errors of I1 and I2.
When using TD1000, the difference is that there is no need

of an external second current source, as TD1000 has two
independent current sources: the main one and the one
coming from the AUX output, selected as a current generator.
It should be understood that this source, as D1000, is actually

an high current voltage source: the output current is a
function of the burden.
The difference between D1000 and TD1000 is that D1000 can

source up to 5 A at 5 VA, while TD1000 can source up to 20 A
at 40 VA; so, you can use the following, simpler, schematic
connection.
A a
B b
I I
C c
1 2
N n
In both instances D1000 or TD1000, the followings are the

test steps.
 Power-on T1000 PLUS, acting on switch (2): the internal
light turns on.
 Set the current adjustment knob (6) and the voltage
adjustment knob (20) completely counter-clockwise.
 If you wish to use the DC voltage output to supply the
relay under test, press the button (69), then use knob (20)
to adjust the voltage value, that is displayed on the LCD
display (23). Connect the DC supply input of the relay to
sockets (63). NOTE: the auxiliary DC supply is not
available with TD1000 PLUS – 15 Hz.
 Connect the A and N inputs of the relay to be tested to the
main current output sockets (13), that correspond to the
current I1 to be generated. For the sake of accuracy and
ease of adjustment, select the smallest range greater that
the maximum test current.
 Connect the TRIP output to the STOP input.
 Select the connection socket measurement pressing the
output socket, the test displays false current or voltage
values.
 If you have D1000, Connect the auxiliary voltage output
sockets (62) to D1000 IN sockets: D1000 converts the
applied voltage into a corresponding output current. On
T1000, select the range of 260 V:
AUX VAC > AUX VAC CONTROL > RANGE > 260 V ESC
NOTE : For the T1000E owners, the 260 V range is not
available; so, select the 130 V range. The lower voltage
could be not enough to allow generating 5 A. However, in
this situation, DON’T SELECT THE 500 V RANGE: there is
not enough power to perform the test.
 Connect D1000 OUT sockets between IN and one of the
differential relay inputs (I2 in the figure), passing through
the T1000 PLUS external current measurement sockets
(67): by doing so, the differential current, generated by
D1000, is metered.
 If you have TD1000, connect the a and n relay inputs to

the red and black sockets of the AC aux output: it will
generate the I2 current.
 Select ON and check if you can easily adjust the desired
current, acting on knob (6). If the maximum test current is
reached with a rotation less than one fifth of the total, this
means that the burden is very low. In this instance, reduce
the output power with the following menu commands:
The 60 VA LED turns on. Select ON again, and check
that the desired current can be reached with ease of
adjustment; if the current is not reached, go back and
select 300 VA.
 Set the save function, as follows.
 Set the timer with the following selections:
Timer start/stop
START > INT (RET)
Edge ESC
NOTE: select stop clean or voltage according to the relay trip

contact connections.
 Set the external current measurement (that is ID) as

follows.
Meters > External I > Enabled > 10 A ESC
 If you have TD1000, select the current output on the

auxiliary source, as follows.
AUX VAC/IAC > AUX VAC/IAC CONTROL > RANGE >
20 A ESC
The output will be displayed in A.
1.15.5 Characteristic curve test

Let us assume that the characteristic curve to be tested has
the shape displayed in the figure. We
take it just as an example.
NOTE: With D1000, the maximum value
for ID is 5 A; if the highest setting of
the curve is greater than 5 A, that part
of the curve will not be tested. With TD1000, the maximum

value for I2 is 20 A; if the current I2 is greater than this,
connect the AUX output as with D1000.
As the curve is of the type parameter versus parameter, all its

points are the result of a threshold test. The area below the
characteristic is the no trip zone; the area above is the trip
zone.
1st test
The trip time is independent upon test parameters; so, it will

be measured in a first test, as follows.
 With I1 = 0, press ON and increase the auxiliary voltage
acting on the knob (20) until the relay trips: the fist point
is found, as it is the differential current when the restraint
current is minimum; test values are:
IA  IB 0  I2 I2
 Restraint Current: IR   
2 2 2
 Differential Current: I D  I A  I B  I 2 (D1000); or,
just generate IA and IB (test with TD1000).
NOTE: it is impossible to test the point with IR = 0, as IR is a

function of Id.
 Now increase slightly the current, and press OFF. Press
now ON+TIME: the delay is the relay trip time. Also this
result can be saved. Reduce ID (or IA – IB) to a value less
than the threshold.
This procedure serves also to verify that all connections are
correct.
2nd test
The trip time is independent upon test parameters; so, it will

be measured in a first test, as follows.
 Slightly increase I1, press ON and increase the other
current acting on the knob (20) until the relay trips:
another point is found and can be saved as the 2nd point of
the curve:
 Restraint Current:
IA  IB I1  ( I1  I 2 )
2 * I1  I 2
IR   
2 2 2
 Differential Current: I D  I A  I B  I1  ( I1  I 2 )  I 2
Other tests
Continue the same way as for test #2, in order to record as

many points (IR-ID) as desired.
1.15.6 Displaying characteristic with X-Pro 1000
First of all, transfer to the computer all records stored in the

memory of the T1000 PLUS. The parameter involved in the
test are Iac and Ext I… you can show them directly in the
software… or edit a formula
1: Select Formula 1
2: Select Ext_I
3: And click this button
by clicking the Formulas button and edit IR = (2*Iac+ExtI)/2

as Formula #1.
4: Edit the Formula 1
5: and confirm
The relative graph could be as follows… not too bad for a

manual test:
1.15.7 Connections for different transformers
Here below the connections for the most common situations.
Beware of the following.
 When you test relays for Yd or Dy Transformers, since

the test is performed in single phase mode, a √3 =
1.732 coefficient is to be applied on the current flowing
in the Y connected pole. For a Yd transformer, the
Restraint and Differential Currents formulas are the
following:
o Restraint Current:
IA I1
 IB  ( I1  I 2 )
3 3
IR  
2 2
o Differential Current:
IA I1
ID   IB   ( I1  I 2 )
3 3
 Therefore, applying current Iac only (from T1000 PLUS)

may result in a trip even when the current generated
by the D1000 is zero: you must increase D1000 current
until the relay contact drops out
 If transformer Taps have to be taken into account, the
above formulas become a little more complex:
o Restraint Current:
IA IB I1 ( I1  I 2 )
 
Tap1 3 Tap2 Tap1 3 Tap2
IR  
2 2
o Differential Current:
IA IB I1 (I  I 2 )
ID     1
Tap1 3 Tap2 Tap1 3 Tap2
1.15.8 Second harmonic restraint test

This test requires that you generate a distorted waveform:
1.5
0.5
0
0 0.005 0.01 0.015 0.02 0.025
-0.5
-1
-1.5
50 Hz 2nd Harm 50 Hz + 2nd Harm
The only way to generate such current waveform is to parallel

the main and auxiliary currents, having selected an 100 Hz
generation on the auxiliary output: the currents add, and

produce a second harmonic distorted current. This current is
applied to one of the relay inputs.
I1 + I2
A a
100 Hz 50 Hz B b
I I C c
2 1
N n
Test procedure:
 Connect the two currents to the relay input;
 Increase I1 only until the relay trips;
 Then increase Aux to increase the current from D1000
or TD1000, until the relay trip drops out.
Take note of the two currents and calculate the 2nd Harm %
 H%: the harmonic percentage is, with D1000:
Ext _ I
H%  *100
Iac  Ext _ I
2 2
Or, with TD1000:

I2
H%  *100
I12  I 22
1.16 PRIMARY END TO END TEST
The purpose of the test is the check the complete protective

scheme of a line differential relay, including the CTs. This kind
of test is particularly complex and requires a big effort in the
coordination of two teams of technicians at both ends of a line.
This test allows the user to check:
Test # Test type Test Execution

1 SOTF pickup Single ended injection
2 Static Differential pick up Single ended injection
3 Dynamic Differential pick-up Double ended injection
4 Internal and External faults Double ended injection
The double ended injection requires 2 x T1000 PLUS in

addition to 2 x GPS and 2 x SWT3.
NOTE
T1000 PLUS is a single phase test set. The phase reference of

the output current depends upon the Mains voltage supply of
the test set.
Since the Mains supply is provided by the Transformer for the

Auxiliary circuits, usually connected as Dy11 or Dy1, it is very
important to identify the phase reference of the LV winding.
For the purpose of quickly identifying the phase reference, the

switching tool SWT3, provided as an option to the T1000
PLUS, will allow switching the supply to phases L1-N, L2-N and
L3-N. More details will be given ahead in this manual.
Due to the complexity of the test, the following will describe

the complete setup of the instruments.
1.16. 1 Test setup
To perform the test it is necessary the following material at

both ends:
 1 x T1000 PLUS: current generator
 1 x GPS: with antenna and cables for the synchronization
 1 x SWT3: to change the Mains supply
 1 x HCSW: high current switch, to rotate the phase angle
of the output by 180°
And follow the following steps:

1. Connect the GPS output to digital input START of the
T1000 PLUS
2. Select GPS Pulse Rate equal to 10 seconds
3. Wait until the green LED Locked is on (locked to

Satellite) and then press the Red button Start/Stop to
start issuing the pulses to the T1000 PLUS.
4. Connect the SWT3 to the three phase supply
5. Connect the power supply of the T1000 PLUS to the
SWT3 output
6. Connect the 100 A output of the T1000 PLUS to the
HCSW by means of the short test leads
7. Connect the output of the HCSW to the CT HV terminals
phase R.
8. NOTE: the connection is the same for secondary relay
testing; T1000 output will be connected to the relay
input, and the current will be reduced to 5 A.
Now switch on the T1000 PLUS. After the start-up, select

relay mode from the menu.
Then follow these steps at the two ends.
 Turn the Main Knob fully counter clockwise
 Press the Right Arrow = ON
 Turn the Main knob clockwise until the reading is about
100 A
 Leave it there and check the relay readings in terms of
o Local Current 1
o Remote Current 1
o Relative Angle
o Measured differential current
In this condition, the differential current and relative angle of

current at the two ends of the line depend upon the phase that
has been selected to supply the T1000 PLUS.
Warning
The two T1000 PLUS must be supplied with the same phase,
either VR, or VY or VB. Since it is almost impossible to
determine what phase is used on each terminal, the SWT3
helps switching the power supply from one phase to another to
get the correct phase reference that will provide either almost
0 A or 400 A
1.16.2 Use of SWT3

The transformer for the auxiliary circuits is usually a Dy1 or
Dy11 transformer. Based on this, we have some cases:
Both transformers at the two ends are Dy1
IR
IB IY
In this case, supposing you have connected the T1000 PLUS to

phase R in the remote end, you have three possibilities on the
local end:
T1000 PLUS is You may measure

approximately
connected to
1 phase R 0 or 400 A
2 phase Y 200 or 346 A (200 x 1.732)
3 phase B 200 or 346 A (200 x 1.732)
If you measure something like 200 or 346 A, it means the two

T1000 PLUS are connected to a different phase reference.
Switch SWT3 to the next position until you get the proper
values.
IR Remote
IR local
IB local IY Remote
IB Remote
IY local
One transformer is Dy1 and the other is Dy11
In this case there are already 60° phase shift between phase R
local end and the phase R of the remote end. Supposing you
have connected the T1000 PLUS to phase R in the remote end,
you have three possibilities on the local end:
T1000 PLUS is You may

connected to measure
approximately
1 phase B 0 or 400 A
2 phase R 200 or 346 A (200
x 1.732)
3 phase Y 200 or 346 A (200
x 1.732)
If you measure something like 200 or 346 A, it means the two

T1000 PLUS are connected to a different phase reference. As
you may see, in this condition Phase B of one end correspond
to the phase R + 180° of the other end.
Switch SWT3 to the next position until you get the proper
values.
1.16.3 T1000 PLUS setup for End to End test

Stop any injection, enter the Relay Menu and set the
instrument as follows:
 MENU > TEST CONTROL > Fault Injection > Timed
 Set Tmax = 0.1 s
 MENU > TIMER START / STOP > START >

EXTERNAL > 24 V
With the above selections, the instrument will inject a fault

current for 100 ms every time the GPS issues a pulse (in our
case, every 10 seconds)
1.16. 4 Line differential tests

With reference to the following table
Test # Test type Test Execution
1 Static Differential pick up Single ended injection
2 SOTF pickup Single ended injection
3 Internal and External faults Double ended injection
we’ll perform each test one by one:
1.16.4.1 SOTF pick up
This test is performed with a single ended injection. No need

to synchronize with the remote end.
 Press On + Time (Left Arrow) on the T1000 PLUS.

 Slowly increase the current output until the relay trip
NOTE
The relay trip can be achieved in two ways:
1. Telephone communication with the control room
2. Connect the trip command, available at the CB control box,
to digital input STOP of the T1000 PLUS
This test is performed with a single ended injection. No need

1.16.4.2 Internal / External fault
This test is performed with a double ended injection. You need

1. Press On + Time (Left Arrow) on the T1000 PLUS.

2. Slowly increase the current output in one and only until the
relay trips
3. Record the measured tripping current
4. Set the same current value on the other end
5. Check if the relay trips:
Start the injection with The relay trips Internal
the GPS fault
Reverse current by 180° The relay does External
using HCSW not trip fault
6. You may have get the following results depending upon the
original connection
Start the injection with The relay External
the GPS doesn’t trip fault
Reverse current by The relay trips Internal
180° using HCSW fault
After this, the test can be considered complete.
1.17 THERMAL RELAY TESTING
Thermal relays are of different types, according to the

measuring method, that can be:
. Thermal image;
. Temperature measurement.
In both instances, the relay behaves in a way that is similar to

an over-current relay, unless for the fact that there is no
threshold to be found, but only to measure the time delay as a
function of the current, that is related to the temperature by
the computation formulas.
The important thing to take into account with these relays is
that any current flow is taken into account; so, the test
procedure is the following:
. Adjust the test current to the desired value;
. Stop the current flow;
. Remove the auxiliary supply, so that the memory is
erased;
. Connect the auxiliary supply;
. Start the timing test, taking care to correct the current
value during the test: because of copper heating, the
current tends to decrease.
. For another test, repeat the procedure for the memory erase.
At the end of the tests, you have the time versus current
curve, from which you can derive the time versus temperature
curve, given the conversion coefficients.
For the test conduction, please refer to paragraph 1.1, test of

over-current relays.
1.18 LOW-VOLTAGE AND MEDIUM VOLTAGE CIRCUIT BREAKER

TESTS
1.18.1. Introduction
We refer to those CB, used on Low Voltage or Medium Voltage

lines, that directly interrupt the voltage when the intervention
criteria is met.
Usually, CB’s behave as over-current relays, with high currents

(and also, usually, long intervention times). The difference
with respect to over-current relays is that CB’s don’t have a
trip contact that drives the line opening: they open the
line by themselves. Therefore, the criteria for timer stop must
be the fact that the current does not flow any more.
1.18.2. Connection to current outputs

turns on.
clockwise.
. The connection of the test set to the CB under test is very
simple:

current, acting on knob (6). The problem with CB’s can be that
they are set for high currents, that can be tested only if T1000
PLUS does not intervene because of its thermal limitations.
Before starting, compare the CB timing characteristic to the
following table, that refers to the 100 A output.
CURRENT MAXIMUM LOAD RECOVERY

OUTPUT POWER TIME TIME
A VA s min
30 300 STEADY -
50 450 30 min 100
75 560 600 45
100 800 60 15
150 900 3 10
200 1000 2 5
250 1000 1 5
. For a normal testing, CB trip times should be no more than

one fifth of the above values.
. Usually, CB’s have a time-dependent characteristic. Of this

CB we want to find and save trip and drop-off thresholds, and
also the time-dependent curve.
. Set the save function, as follows.


STOP > INT (RET)
NOTE: the INT selection for STOP makes the timer to stop as
soon as the current is cut by the CB.
1.18.3. I> Threshold
The first session is finding threshold I>. Select ON; slowly

increase the current. As the CB trips, pressing the multi-
function knob the tripping value can be saved. The TRIP LED
(43) turns on for 5 seconds; during 5 seconds, parameters at
trip are displayed; then, the standard measurement is
restored. Confirm save results pressing the multi-function

knob, and proceed.
1.18.4. Intervention curve
Now we can measure trip timings, following the I-t curve with
Now, press ON and pre-adjust the first test current: if the CB
trips, don’t save test result; go OFF. Select ON+TIME: as the
CB trips, test goes OFF; pressing the multi-function knob,
tripping values can be saved. Confirm save results pressing
the multi-function knob, and proceed with other test currents,
until all points to be tested are measured.
1.19 CT SATURATION KNEE TEST
1.19.1. Introduction
The saturation knee test of a CT is performed applying a

voltage to the CT secondary side, and slowly increasing it
while measuring the current sunk by the CT. When the
saturation approaches, the current increases sharply: this is
the saturation knee.
More precisely, the IEC standard C.57.13, paragraph 6.10.2

defines the knee point as “the value of the voltage for which a
voltage increase of 10% causes a current increase of 50%”.
T1000 allows to measure and save the applied voltage and the
absorbed current. Repeating the measurements at various
voltage values it is possible to record the I vs. V curve; then,
applying the definition, the knee point can be located
graphically.
NOTE: the test set T3000 performs the measurement in an

automated way.
The voltage to be applied to perform the test is up to 250 V

(500 V for the T1000E model). Before performing the test, you
can compute the nominal knee as follows.
. Take from the label the following parameters: nominal

current IN; VA rating; accuracy class (for instance, 5P20).
Then, compute:
. Maximum voltage at IN: Max V(IN) = VA / IN;
. Knee voltage = Max V(IN) * P
Example: IN = 5 A; VA = 20 VA; class 5P20.

. Max V(IN) = 20 / 5 = 4 V;
. Knee voltage = 4 * 20 = 80 V.
This knee can be tested very easily. The maximum nominal

knee voltage is 200 V, as you need to proceed some more
further.
1.19.2. Test set connection
The saturation knee test of a CT is performed applying a

voltage to the CT secondary side, and slowly increasing it
while measuring the corresponding current. The connection is
shown in the following.
All you have to do is to connect the main AC voltage output to

the CT’s secondary, putting in series the internal current
meter.
1.19.2. Test execution

The test execution is the following one.
 Compute the nominal saturation voltage as explained
above.
 In the menu, select:
Test control > Save > Manual ESC
 Press ON, adjust the first voltage at about 20% of the
nominal saturation voltage; then, press Menu and
Save;
 Keep on adjusting and saving with steps that you can
decide, but they will be reduced to 10% and to 5% as
you get close to the nominal voltage knee;
 Keep on with small voltage increments, and watch the
absorbed current. When you see it increasing by 50%
when you increment the voltage of 5%, then the knee
has been reached.
 SLOWLY REDUCE THE TEST VOLTAGE: if you don’t,
there will be a magnetic remanence which will cause
troubles as you set the CT in service.
 Connect to a PC, start the program, download test
results.
 On test results, create the following formulas:
. Formula 1: 1.1*Vac;
. Formula 2: 1.5*EXT_I
 The test result is the following one.
In this CT, the nominal voltage knee is 160 V. When Vac is

165 V, formula 1 says 181 V; correspondingly, Formula 2 says
45 mA. Now, go to the Vac value of 181 V, and you find a
current sink of 45 mA: this means that 165 V is the measured
voltage knee.
AP PE N DI X 1 O VE R C UR RE NT R EL A YS
There are many types of time-dependent curves. They follow

standards set by IEC, IEEE, IAC, ANSI, US, and are defined as
Standard Inverse; Very Inverse; Extremely Inverse or so.
The curve is defined by two parameters:

. The setting threshold I>;
. Another parameter, that can be either the Time Multiplier (K
or KT), or the Time Dial setting (tI>), that is the delay with
Current equal to 10 times the Pick-up Current (10I>).
From these parameters the diagram can be drawn, as follows.
A) Parameter KT
In this instance, IEC and IEEE curves correspond to the

following formula.
KT* a
t (s)  c
b
 I 

  1
 IR 

Constants of the formula change according to the type of
curve; they are summarised in the following table.
IEC, IEEE a c b
IEC Class A Standard Inverse 0.14 0 0.02
IEC Class B Very Inverse 13.5 0 1
IEC Class C Extremely Inverse 80 0 2
IEC Long Time Inverse 120 0 1
IEC Short Time Inverse 0.05 0 0.04
IEEE - US Moderately Inverse 0.0515 0.114 0.02

IEEE - US Very Inverse 19.61 0.491 2
IEEE - US Extremely Inverse 28.2 0.1217 2
IEEE - US Inverse 29.75 0.9 2

IEEE - US Short Inverse 0.0171 0.0131 0.02
With IAC and ANSI standards, the different curves correspond

to the following formula.
 
 
 b d e 
t (s)  K * a    3 
  I  c   I  c 
T 2
 I  
  I  
I  c 
 I R   R   R  


IAC, ANSI a b c d e
IAC Inverse 0.2078 0.863 0.8 -0.418 0.1947
IAC Short Time 0.0428 0.0609 0.62 -0.001 0.0221
Inverse
IAC Long Time 80 0 2 2 2
Inverse
IAC Very 0.09 0.7955 0.1 -1.2855 7.9586
Inverse
IEC Extremely 0.004 0.6379 0.62 1.7872 0.2461
Inverse
ANSI - 0.0399 0.2294 0.5 3.0094 0.7222

Extremely
Inverse
ANSI - Very 0.0615 0.7989 0.34 -0.284 4.0505
Inverse
ANSI - Normal 0.0274 2.2614 0.3 -4.1899 9.1272
Inverse
ANSI - 0.1735 0.6791 0.8 -0.08 0.1271
Moderately
Inverse
With US standards, the different curves correspond to the

following formula.
 
 
 b 
t ( s )  K T * a  
c
  I  
 
 
  1
  IR  

US a c b
US Moderately Inverse 0.0226 0.0104 0.02
US Inverse 0.18 5.95 2
US Very Inverse 0.0963 3.88 2
US Extremely Inverse 0.0352 5.67 2
Here are the nominal inverse time characteristics for Normal,

Very, Extremely and Long Time Inverse, plotted for KT from
0,1 to 1, for the case of IEC definitions.
B) Parameter t (I>)
The Time Current Curves are calculated with the following

equation:
ts  
A
 F  (tI )
a
I where:
   1
 IR 
1
 A 
F  B
 10a  1 
 
t(I>) = Set time delay at 10 times the Pick-up Current.
In this instance, parameters are summarised in the following

table.
Curve Type with

Time Dial Setting
A B a
IEC Class A 0.14 0 0.02
Standard Inverse
IEC Class B Very 13.5 0 1
Inverse
IEC Class C 80 0 2
Extremely Inverse
IEC Long Time 120 0 1
Inverse
IEC Short Time 0.05 0 0.04
Inverse
IEEE - US 0.0104 0.0226 0.02

Moderately Inverse
IEEE - US Very 3.88 0.0963 2
Inverse
IEEE - US 5.67 0.0352 2
Extremely Inverse
IEEE - US Inverse 5.95 0.18 2
IEEE - US Short 0.00342 0.00262 0.02
Inverse
IAC Normally 1.7868 0.03593 2.0938

Inverse
IAC Short Inverse 0.05326 0.006786 1.2969
IAC Long Inverse 1.1228 0.43718 1

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DATE: 06/09/2011 DOC.MIE91093 REV. 1.

REVISIONS SUMMARY VISA

1.28 11, 13-15 2/02/2010 Added test header Lodi

1.28 100-111 1/10/2010 Differential relay Lodi

SHORT FOREWORD ............................................................................. 7

1.6.3. F> Threshold and drop-off ........................................ 50

1.15.3 The Restraint and the Differential current ... 114

Copies, reprints or other reproductions of the content or of parts of this publication

Copyright 2012© ISA S.R.L. Italy – All rights reserved.

Dear T1000 PLUS user,

I often wondered why the user’s manual is not very much

This is why I decided to split the T1000 PLUS manual in three:

Have a good work with T1000 PLUS!

The Product hereafter described is manufactured and

The application guide is published by the Seller to be used

The Seller declines any difficulties arising from unknown

The warranty includes the repair time and the materials

The Product is CE marked, and has been tested to operate

. Pollution degree 2: normally, non conductive pollution

Mains supply characteristics are:

. The symbol is located closet o the round socket.

. The symbol is located close to the mains supply

The Product generates voltages and currents that may be

DO NOT OPERATE THE PRODUCT IF NOT CONNECTED TO

The connection to ground is provided through the mains

IF THE GROUND IS NOT AVAILABLE AT THE MAINS

In case of doubt, please contact your Seller. The Seller, and

Type of relay IEEE code PARAGRAPH

* For distance relays three T1000 PLUS are necessary.

In addition to the above, T1000 PLUS can test:

The instrument contains three separate generators:

All outputs are adjustable and metered at the meantime on

The basic T1000 PLUS function is to generate current and

This is also why we have added the reduced power feature.

In this situation it is possible to connect resistors in series;

Additional features are:

The instrument is housed in a transportable aluminum box,

NOTE: WINDOWS is a trademark of MICROSOFT inc.

In this paragraph, and the following ones, we describe how to

The following examples include all information related to the

The second comment is about saving test results. Before

All tests performed after setting the header will be grouped

Once selected the Header, the following window is displayed.

The operation to input the header is the following.

During a test, results can be memorized selecting Test

With the selection Automatic at trip, data are immediately

With the selection Manual, it is possible to save data at any

Once results are saved, it is possible to review or to delete

Pressing on the relay serial number you access a window with:

If you go to the number of tests and press, tests are shown

1.1 OVERCURRENT RELAY TESTING

There are many families of time-dependent overcurrent relays.

For the test of undercurrent relays, the following notes are to

The following is the connection schematic.

1.1.2. Connection to current outputs

. Power-on T1000 PLUS, acting on switch (2): the internal light

. Set the current adjustment knob (6) completely counter-

. If you wish to use the DC voltage output to supply the relay

. Connect the relay to the two main current output sockets

. Connect the TRIP output to the STOP input.