17.7 PROTECTION SCHEMES
17 COMMISSIONING
Indications and Operations are as outlined under Phase Time Overcurrent 1.
Blocking From Logic Inputs:
1. Inject voltage and current above minimum at a frequency to cause a pickup.
2. Assert a logic input to provide a "Block Underfreq 1 (2)". The PICKUP indicator should immediately go out.
3. Repeat steps 1 and 2 for logic input "Block 1 TRIP Relay" as required.
Timing:
1. Connect the "Stop Trigger."
2. Set the voltage source prefault mode to nominal voltage, current and frequency.
3. Set the voltage source fault mode to nominal voltage and current, but with a frequency below pickup.
4. Set the source to prefault mode, reset the timer, and apply to the relay.
5. Jump the source to fault mode and measure the operating time.
6. Repeat steps 4 and 5 four more times and obtain an average of the time intervals.
7. Reset the relay and disconnect the "Stop Trigger."
17
17-
750/760 Feeder Management Relay
GE Power Management
40
Courtesy of NationalSwitchgear.com