GE Feeder Management Relay 750 Instruction Manual

8-18 750/760 Feeder Management Relay GE Multilin8.4 PROTECTION SCHEMES 8 COMMISSIONING TESTS82. Inject current below the pickup level into Phase A and slowly increase until the Pickup LED is on. Note the pickup valueis the pickup current of the Curve in use.3. Slowly reduce the current into Phase A until the Pickup LED goes off and note the dropout level, which should be 2%of CT less than pickup when pickup ≤ CT or 97 to 98% of pickup when pickup > CT.4. Reduce the current to zero.5. Repeat Steps 2 to 4 for current injected into Phases B and C.6. Set all input voltages to 0 and slowly increase Phase A current until the Pickup LED comes on. Check that this currentis 9 to 11% of the measured full voltage pickup current.7. Increase input voltage Vab until the Pickup LED goes out. This should be at 9 to 11% of the nominal phase-phase volt-age. This test establishes the lower knee of the operating characteristic.8. With the Pickup LED still off, increase voltage Vab to 60% of the nominal phase-phase voltage.9. Increase the Phase A current until the Pickup LED comes on. This should be at 59 to 61% of the full voltage measuredpickup current.10. With the Pickup LED still off, increase voltage Vab to 130% of nominal.11. Increase Phase A current to 90% of normal pickup and hold this value. Slowly decrease Vab until the Pickup LED justcomes on. This should be at 89 to 91% of nominal Vab. This establishes the upper knee of the characteristic, andshows the pickup is not altered above 90% voltage.12. Reduce current and voltages to 0.13. Repeat Steps 6 through 12 for current injected in Phase B and controlling voltage Vcb.14. Repeat Steps 6 through 12 for current injected in Phase C and controlling voltage Vca.To check trip timing with voltage restraint, set the input voltage to a given level, establishing a new pickup current, and thenfollowing the procedure outlined earlier under Timing.b) PHASE TOC 2The procedure to test this element is identical to that for Phase TOC 1, except for the blocking from logic inputs, in whichcase the following procedure should be used:1. Inject current to cause a Pickup.2. Assert a logic input to provide a "Block Phase Time 2". The Pickup LED should immediately go out.3. Repeat Steps 1 and 2 for logic inputs "Block Phase O/C", "Block All O/C" and “Block 1 Trip Relay” as required.c) PHASE IOC 1The procedure to test this element is identical for Phase TOC 1, except for the procedures below. Pickup, indication andoperation are subject to the "phases required for operation" test, but not subject to the "linear reset timing" and "voltagerestrained Phase TOC" tests.The following procedure checks pickup with two phases for operation:1. Inject current into Phase B at 150% of pickup.2. Inject current at a level below the pickup level into Phase A.3. Slowly increase the Phase A current until the Pickup LED comes on and note the pickup value.4. Slowly reduce the Phase A current until the Pickup LED goes out. Note the dropout level, which should be 2% of CTless than pickup when pickup ≤ CT or 97 to 98% of pickup when pickup > CT.5. Repeat Steps 1 through 4 for phase pair B and C and phase pair C and A.The following procedure checks pickup with three phases for operation:1. Inject current into Phases B and C at 150% of pickup.2. Inject current at a level below the pickup level into Phase A.3. Slowly increase the Phase A current until the Pickup LED comes on and note the pickup value.