GE 750 Instruction Manual page 383

CHAPTER 7: COMMISSIONING
7.5.5 Overfrequency
Monitoring
7.5.6 Power Factor
750 FEEDER MANAGEMENT RELAY – INSTRUCTION MANUAL
 Wait for 90 seconds (fast rate) or 90 minutes (slow rate) to ensure the
relay has properly measured the input ramping-rate.
The relay should not pickup.
 Cycle the relay power supply Off then On.
 Adjust the ramp-rate to a higher rate and again apply and, if the relay
doesn't pickup, cycle the relay power supply Off then On.
 Repeat this procedure until the element generates an output.
The following procedure tests Analog Input Rate Timing:
 Connect the Stop Trigger.
 Preset the ramp-rate to a minimum of 110% of the pickup.
 Turn the current off, and reset the timer.
 Inject the preset current into the analog input and note the measured
delay time.
 Reset the timer.
 Repeat Step 3 four more times and obtain an average of the time
intervals.
 Disconnect the Stop Trigger.
To test Overfrequency monitoring, use the test connections specified in FIGURE 7–1: Relay
Test Wiring – Wye Connection or FIGURE 7–2: Relay Test Wiring – Delta Connection on page
7–5. The Indications and Operations are as outlined for Phase TOC 1 on page 7–25, except
that this element has no Trip function.
 Inject voltage at a frequency below the pickup level into Phase A.
 Slowly increase the frequency until the element generates an output.
 Slowly reduce the frequency until the element resets.
The following procedure checks the Overfrequency monitoring Timing:
 Connect the Stop Trigger.
 Preset the voltage source frequency to a minimum of 110% of pickup.
 Turn voltage off and reset the timer.
 Inject the preset voltage into phase A and note the measured delay time.
 Reset the timer.
 Repeat Step 3 four more times and obtain an average of the time
intervals.
 Disconnect the "Stop Trigger".
To test Power Factor monitoring, use the test connections specified in FIGURE 7–1: Relay
Test Wiring – Wye Connection or FIGURE 7–2: Relay Test Wiring – Delta Connection on page
7–5. The Indications and Operations are as outlined for Phase TOC 1 on page 7–25, except
that this element has no Trip function.
MONITORING
7 - 55