GE Power Management 750/760 Feeder Management Relay 17-
43
17 COMMISSIONING 17.8 MONITORING
17
17.8 MONITORING 17.8.1 PHASE CURRENT LEVEL
Test Connections per Figure 17–1: RELAY TEST WIRING – WYE CONNECTION or Figure 17–2: RELAY
TEST WIRING – DELTA CONNECTION on page 17–4.
1. Set the Delay time to 0.
2. Inject current at a level below the pickup level into phase A.
3. Slowly increase the current until pickup is reached and the element generates an output.
4. Slowly reduce the current until the element resets, which should be 2% of CT less than pickup when
pickup
≤
CT or 97 to 98% of pickup when pickup > CT.
5. Repeat steps 2 to 4 for phase B and C current.
6. Set the Delay timer to the required setting.
Indications and Operations caused by the various Functions are as outlined under Phase Time O/C,
with the following exception.
There is no Trip function for this element.
Timing:
1. Set the test source to a current at least 110% of pickup. Turn off and reset the timer.
2. Inject current into the relay and measure the time to operate.
3. Repeat step 2 four more times and obtain an average of the time intervals
4. Disconnect the Stop Trigger.
17.8.2 NEUTRAL CURRENT LEVEL
Test Connections per Figure 17–1: RELAY TEST WIRING – WYE CONNECTION or Figure 17–2: RELAY
TEST WIRING – DELTA CONNECTION on page 17–4.
The testing for this element is the same as for the Phase Current Level element, except current is the residual
current injected into the phase current inputs.
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