GE Power Management 750/760 Feeder Management Relay 17-
27
17 COMMISSIONING 17.7 PROTECTION SCHEMES
17
17.7.10 NEUTRAL INSTANTANEOUS OVERCURRENT 1
The procedure to test this element is identical to that outlined in Section 17.7.5: PHASE INSTANTANEOUS
OVERCURRENT 1 on page 17–24, with the following exceptions.
Current is injected into any one phase, and the element is not subject to the test "phases required for opera-
tion”, and not subject to the tests “linear reset timing” and “voltage restrained time overcurrent”.
Blocking From Logic Inputs
1. Inject current to cause a pickup.
2. Assert a logic input to provide a "Block Neutral Inst 1". The PICKUP indicator should immediately go out.
3. Repeat 1 and 2 for logic inputs "Block Neutral O/C", "Block All O/C" and “Block 1 TRIP Relay” as required.
17.7.11 NEUTRAL INSTANTANEOUS OVERCURRENT 2
The procedure to test this element is identical to that outlined in Section 17.7.5: PHASE INSTANTANEOUS
OVERCURRENT 1 on page 17–24, with the following exceptions. Current is injected into any one phase, and
the element is not subject to the test "phases required for operation”, and not subject to the tests “linear reset
timing” and “voltage restrained time overcurrent”.
Blocking From Logic Inputs
1. Inject current to cause a pickup.
2. Assert a logic input to provide a "Block Neutral Inst 2". The PICKUP indicator should immediately go out.
3. Repeat 1 and 2 for logic inputs "Block Neutral O/C", "Block All O/C" and “Block 1 TRIP Relay” as required.
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