APPENDIX B
B-3
ACTION REFERENCEMALFUNCTION
3. Read the phase instantaneous trip delay and
verify that the overcurrent condition is present for
longer than this time.
4. Ensure that the trip relay wiring to the breaker is
correct at terminals 41 and 57.
1. Verify that the ground fault sensing is enabled in
setpoints mode.
2. Check that the sensing system selected in set-
points, either Residual or Zero sequence, corre-
sponds to your system.
3. For Zero sequence sensing systems, verify that
the CT primary ratio entered in setpoints mode
correspond to the installed CT.
4. Check that the correct ground fault overcurrent
pickup has been entered in setpoints.
5. Verify that the correct protection curve, pickup
level and curve number have been selected for
the level of ground fault encountered.
6. Ensure that the fault current is present for longer
than the time necessary to trip according to the
selected time/overcurrent curve.
7. Check all system wiring.
8. Perform calibration mode relay test to verify the
operation of the trip relay.
1. Check that the ground fault alarm is enabled in
setpoints.
2. Identify the relay to which the alarm has been
assigned from setpoints mode page 3. Ensure
that it is correctly wired to the alarm annunciation.
3. Check that the ground fault alarm level is low
enough to cause an alarm before the trip level is
reached.
4. Read the ground fault alarm time delay and en-
sure that the alarm condition is present for longer
than this time. Note that if the ground fault current
level rises to the trip level before the timed period,
a trip will occur before the alarm.
5. Perform calibration mode relay test to verify the
operation of the assigned relay(s).
1. Check that the ground fault instantaneous trips
are enabled in setpoints.
Setpoints page 2.
Relay wiring diagram.
Setpoints page 3.
Setpoints page 3.
Setpoints page 3.
Setpoints page 3.
Setpoints page 3 and Instruc-
tion manual section 6.
Setpoints page 3 and Instruc-
tion manual section 6.
Relay wiring diagram.
Setpoints page 8.
Setpoints page 3.
Setpoints page 3 and relay
wiring diagram.
Setpoints page 3.
Setpoints page 3.
Setpoints page 8.
Setpoints page 3.
11. Ground fault protection
not energizing trip
relay(s).
12. Ground fault protection
causes trip but no
alarm.
13. Ground fault instantane-
ous trips not operating.
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