GE Feeder Management Relay 750 User Manual

GE Multilin 750/760 Feeder Management Relay 8-43
8 COMMISSIONING TESTS 8.6 CONTROL SCHEMES
8
The procedures below check the control of overcurrent protection features. Use the following procedure to check Phase
IOC 1 Blocking:
1. Set a test current, in the number of phases required to generate an output, to a level above the pickup of this element
then turn the current off.
2. Apply a Close command, as described above, and immediately inject the test current to the relay. The element will not
pickup as it is blocked by manual close blocking. Wait until the element operates, as shown by the Pickup LED coming
on, at the end of the programmed Manual Close Block Time.
3. Turn the current off. The time interval can be checked in the Event Recorder.
For Neutral IOC 1 Blocking, Ground IOC Blocking, Sensitive Ground IOC Blocking, and Neg Seq IOC Blocking, follow the
procedure described for Phase IOC 1 Blocking above, injecting current as appropriate.
The following procedure checks Phase TOC 1 Raised Pickup:
1. Ensure all other overcurrent features are "Disabled".
2. Manual Close Blocking will raise the pickup setting of the curve normally used by this feature the programmed percent-
age. Set a test current to a level between the normal pickup setting and the raised setting, then turn the current off.
3. Apply a Close command, as described above, and immediately inject the test current into the relay. Phase TOC will not
pickup as the pickup current is raised. Increase the injection current until the Pickup LED comes on, before the manual
close feature times-out and returns the pickup to normal. Check that the raised pickup level is correct. Turn current off,
and wait until the alarm is removed from the display.
4. Set a test current to a level between the normal pickup setting and the raised setting, then turn the current off.
5. Apply a Close command, as described above, and immediately inject the test current into the relay. Phase TOC will not
pickup as the pickup current is raised.
6. At the end of the programmed MANUAL CLOSE BLOCK TIME, the Pickup LED should come on, as the pickup setting has
returned to normal. When this happens, reduce the injection current until the Pickup LED goes out. The MANUAL
CLOSE BLOCK TIME can be checked in the Event Recorder.
For Neutral TOC 1 Raised Pickup, Ground TOC Raised Pickup, Sensitive Ground TOC Raised Pickup, and Neg Seq TOC
Raised Pickup, follow the procedure outlined for Phase TOC 1 Raised Pickup above, injecting current as appropriate.
To check the Select Setpoint Group function, apply a manual close and verify that the selected setpoint group becomes
active when the breaker closes. Verify that settings return to the previous setpoint group after the MANUAL CLOSE BLOCK
TIME expires.
8.6.4 COLD LOAD PICKUP BLOCKING
Make the test connections specified in Figure 8–1: Relay Test Wiring – Wye Connection or Figure 8–2: Relay Test Wiring –
Delta Connection on page 8–3. The following procedure checks the Cold Load Pickup Function and Timer Control:
1. Enable the
COLD LOAD PICKUP setpoint to cause the relay to go into cold load pickup operation after the OUTAGE TIME
BEFORE COLD LOAD setpoint expires. Check that any selected output relays have operated. If the function is selected
as Alarm, the alarm message and LED should also be turned on.
2. Inject a current in any phase below 10% of nominal, and slowly increase. The relay should go into cold load operation
when the current is above 10% of nominal. The alarm message and LED should reset and any output relays pro-
grammed to operate should dropout after a time interval equal to the cold load pickup block time. This interval can be
checked in the Event Recorder.
3. Reduce this current to 3% of nominal and simultaneously start a timer. This feature should generate an output at the
end of the
OUTAGE TIME BEFORE COLD LOAD setting.
The procedures below check the control of overcurrent protection features. The following checks Phase IOC 1 Blocking:
1. Set a test current, in the number of phases required to generate an output, to a level above the pickup of this element
then turn the current off.
2. Assert a Cold Load Pickup logic input, and immediately apply the test current to the relay. The element will not pickup
as it is blocked by cold load pickup blocking. Wait until the element operates, as shown by the Pickup LED coming on
at the end of the programmed
COLD LOAD PICKUP BLOCK time.
Courtesy of NationalSwitchgear.com

GE Feeder Management Relay 750 Specifications

General

Brand	GE
Model	Feeder Management Relay 750
Category	Protection Device
Language	English