GE 750 Instruction Manual page 479

17 COMMISSIONING
Instantaneous O/C Blocking:
1. Select the
MAX NUMBER OF RECLOSURE SHOTS
set the test set to a current level above the pickup of this element, and inject into a phase input. The relay
should trip and reclose 4 times. Turn off the current, reset the relay and close the breaker.
2. Enable Phase Inst OC 1 Blocking for Reclosure Shot 1. Turn on the current. The relay should trip and
reclose once. The Shot in Effect display should show 1. The PICKUP indicator should be off. Once the
Autoreclose Reset Time has expired, the relay will then pickup, trip and reclose until lockout as the fault
current is still present. Turn off the current, reset the relay and close the breaker.
3. Disable Phase Inst OC 1 Blocking for Reclosure Shot 1, and Enable for Reclosure Shot 2. Turn on the cur-
rent. Reclosure Shot 2 should not operate, and the PICKUP indicator will be off. Turn off the current and
reset the relay.
4. Repeat procedure 3 using Phase Inst OC 1 Blocking for each of the 4 Reclosure Shot settings.
5. Repeat steps 1-4 for each Instantaneous OC Blocking setpoint, disabling each Instantaneous OC element
before moving on to the next.
Raised Pickup of Time O/C Elements:
1. Keep the Maximum Number of Reclosure Shots at 4. With the Phase Time OC 1 function selected as Trip
+ AR, set the test set to a current level above the pickup of this element. Turn off the current, reset the
relay and close the breaker.
2. In Reclosure Shot 1 settings, select the Phase Time OC 1 Raised Pickup such that it brings the pickup
level just below the actual current that is being injected. Turn on the current. The relay should trip and
reclose 4 times.
3. In Reclosure Shot 1 settings, select the Phase Time OC 1 Raised Pickup such that it brings the pickup
level just above the actual current that is being injected. Turn on the current. The relay should trip and
reclose once. The Shot in Effect display should show 1. The PICKUP indicator should be off. Once the
Autoreclose Reset Time has expired, the relay will then pickup, trip and reclose until lockout as the fault
current is still present. Turn off the current, reset the relay and close the breaker.
4. Return Phase Time OC 1 Raised Pickup to 0 for Reclosure Shot 1, and set it to a level that is above the
actual current for Reclosure Shot 2. Turn on the current. Reclosure Shot 2 should not operate, and the
PICKUP indicator will be off. Turn off the current and reset the relay.
5. Repeat procedure 4 using Phase Time OC 1 Blocking for each of the 4 Reclosure Shot settings.
6. Repeat steps 1-5 for each Time OC Raised Pickup setpoint, disabling each Time OC element before mov-
ing on to the next.
Select Setpoint Group:
1. Keep the Maximum Number of Reclosure Shots at 4. In Setpoint Group 1, Enable
AR . In Setpoint Group 2, Enable
to Trip + AR . In Setpoint Group 4, Enable
1
each element.
2. For Reclosure Shot 1 settings, set the
Group 3 for
RECLOSURE SHOT 2
3. Set the test set to a current level above the pickup of these elements. With the current source off, Reset
the relay, and clear the event recorder.
4. Turn on the current. The relay should Trip + AR 4 times caused by the following elements, in order, Phase
Time OC 1, Phase Time OC 2, Phase Inst OC 1, Phase Inst OC 2, Phase Time OC 1. The event recorder
will show this sequence of events. Turn off the current, and reset the relay.
GE Power Management
Courtesy of NationalSwitchgear.com
to be 4. With Phase Inst OC 1 function selected as Trip + AR ,
to Trip + AR . In Setpoint Group 3, Enable
PHASE TIME OC 2
PHASE INST OC 2
SELECT SETPOINT GROUP
, Group 4 for
RECLOSURE SHOT 3
750/760 Feeder Management Relay
17.9 CONTROL SCHEMES
PHASE TIME OC 1
to Trip + AR . Select the same pickup level for
setpoint to Group 2 . Similarly, set it to
, and Group 1 for
RECLOSURE SHOT 4
17
to Trip +
PHASE INST OC
.
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