M-3425 Instruction Book
6–20
24 Volts/Hz Inverse Time
VOLTAGE INPUTS: V1
CURRENT INPUTS: none
TEST SETTINGS:
Inverse Time Pickup
P
%
(100 to 200)
Inverse Time Curve
C
(1 to 4)
Time Dial (curve 1)
K
(1 to 100)
Time Dial (Curves 2-4)
(0.0 to 9.0)
Reset Rate
R
seconds
(1 to 999)
Programmed Outputs
Z
OUT
(1 to 8)
Functions 24DT, 27, 27TN
Disable
Functions 32, 59, 81, 81R
Disable
1.
Set 24DT #1 Pickup to 200%, and Delay to 30 cycles.
2.
Disable functions as shown. See Section 3.2, Initial Setup Procedure/Settings, Configure Relay
Data, for procedure.
3.
Confirm settings to be tested.
4.
Connect voltage input in Configuration V1 designated above. See Section 6.1, Equipment/Test
Setup for configurations.
5.
The Volts per Hertz pickup level of a percentage setting at nominal frequency (50 or 60 Hz) is:
Pickup voltage = (P% ÷ 100) x (Nominal Voltage) where the Nominal Values have been
programmed in the system setup data described in Section 2.1, Configuration and are recorded on
the Figure A-2, Communication Data & Unit Setup Record Form.
6.
Test levels may be chosen at any percentages of Nominal Voltage which are a minimum of 5%
higher than the pickup percentage, P%. (Suggest 4 or 5 test levels chosen and calculated in Step
5.)
7.
Pickup Test: Hold the TARGET RESET button in and slowly increase the voltage on A phase
until the VOLTS/HZ LED light goes on or the pickup indicator operates on the computer target
screen. The voltage level of operation will equal P volts ±1%. Release the TARGET RESET
button and decrease the voltage and the output LEDs will go out. Press TARGET RESET button
to remove targets.
8.
Time Test: With output contacts (Z) connected to stop the timer, apply voltage equal to the
chosen test level calculated in step 5 on A phase and start timing. The operating time will be as
read from the appropriate Inverse Curve Family and K (Time Dial) setting (refer to Appendix D,
Inverse Time Curves). The measured time should be within the time corresponding to
"
1% of
the pickup value.
9.
Repeat step 6 for all test levels chosen. The curve portion extending to lower than P% V/Hz
values are inactive and can be ignored. The tested points verify the operating times of the
function.
10.
To test the reset time, begin timing immediately when the input voltage is reduced below pickup
value.
11.
Holding the TARGET RESET Button in, stop timing when the TARGET LED goes out. The time
should be the reset time within ±1 cycle or ±1%, whichever is greater.
12.
If testing is complete, enable any functions disabled for this test. If other tests are to be
completed, check the proper functions to disable for the next test and proceed from this
configuration.
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■
■
■
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NOTE: If retesting is required, the unit should be powered down or wait for the programmed reset
time period before the next test to assure resetting of the timer.
Summary of Contents for M-3425
Page 1: ...Instruction Book M 3425 Generator Protection ...
Page 14: ... 13 M 3425 Generator Protection Relay Figure 1 External Connections ...
Page 33: ...x M 3425 Instruction Book This Page Left Intentionally Blank ...
Page 89: ...M 3425 Instruction Book 2 52 This Page Left Intentionally Blank ...
Page 125: ...1 3 A B C M 3425 Instruction Book 4 26 This Page Left Intentionally Blank ...
Page 187: ...M 3425 Instruction Book 6 50 This Page Left Intentionally Blank ...
Page 207: ...M 3425 Instruction Book C 4 This Page Left Intentionally Blank ...
Page 209: ...D 2 M 3425 Instruction Book Figure D 1 Volts Hz 24 Inverse Curve Family 1 Inverse Square ...
Page 210: ...Inverse Time Curves Appendix D D 3 Figure D 2 Volts Hz 24 Inverse Family Curve 2 ...
Page 211: ...D 4 M 3425 Instruction Book Figure D 3 Volts Hz 24IT Inverse Curve Family 3 ...
Page 212: ...Inverse Time Curves Appendix D D 5 Figure D 4 Volts Hz 24IT Inverse Curve Family 4 ...
Page 215: ...D 8 M 3425 Instruction Book Figure D 5 Definite Time Overcurrent Curve ...
Page 216: ...Inverse Time Curves Appendix D D 9 Figure D 6 Inverse Time Overcurrent Curve ...
Page 217: ...D 10 M 3425 Instruction Book Figure D 7 Very Inverse Time Overcurrent Curve ...
Page 218: ...Inverse Time Curves Appendix D D 11 Figure D 8 Extremely Inverse Time Overcurrent Curve ...
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