Transfer Scheme - GE 750 Instruction Manual

Control Schemes

Transfer Scheme

GE Multilin
15. Turn the voltage on. The Close Relay should operate after the delay
programmed in
UNDERFREQ RESTORE DELAY
16. If Underfrequency 2 initiation is to be checked, change Underfrequency
Restoration to Disabled, Underfrequency 1 to Disabled, Underfrequency 2 to
Trip and repeat Steps 2 through 8.
The following procedure checks the minimum voltage for underfrequency
restoration:
1. Assert or De-assert a logic input to simulate an open breaker.
2. Set
UNDERFREQ RESTORE DELAY
3. Inject a voltage below the
voltage input of the relay.
4. Reduce the injected frequency to cause an underfrequency trip, then increase
the frequency to nominal.
5. Slowly raise V until the Close relay operates. This is the operating level of
a
setpoint Underfreq Restore Min Volts.
The following procedure checks the minimum frequency for underfrequency
restoration:
1. Assert or De-assert a logic input to simulate an open breaker.
2. Set
UNDERFREQ RESTORE DELAY
3. Inject nominal voltage into the bus voltage input of the relay.
4. Reduce the injected frequency to cause an underfrequency trip.
5. Slowly increase the frequency until the Close Relay operates. This is the
operating level of the
UNDERFREQ RESTORE MIN FREQ
a) Common Logic
1. Ensure that the Phase Inst O/C 1, Neutral Inst O/C 1, Line Undervoltage 3, Line
Undervoltage 4, Synchrocheck and Logic Input features in the relays pro-
grammed as Incomer 1 and Incomer 2 have been tested and are Enabled.
2. Ensure that the Synchrocheck and Logic Input features in the relay
programmed as Bus Tie has been tested and is "Enabled".
3. Ensure all circuit breakers are disconnected from their normal positions in the
primary circuit, are open and operating properly, and the close and trip circuits
have been tested and are energized.
4. De-assert Logic Inputs 1, 2, 3, 4, 5, 6, 11, 12, and 13 at both Incomer relays.
De-assert Logic Inputs 1, 2, 3, 4, 5, 6, and 11 at the Bus Tie relay.
5. At this time both of the Incomer relays should have Output Relays 1 and 4
operated, Output Relays 5 through 7 reset, and be displaying the message
Transfer Not Ready. At the Bus Tie breaker relay, Output Relays 4 through 7
should be reset (de-energized).
6. Parallel the Line to Bus voltage inputs of the Incomer 1 relay to the Bus voltage
input of the Bus Tie relay and connect this circuit to a voltage source (Source 1
for these tests). Do not energize the source.
7. Parallel the Line to Bus voltage inputs of the Incomer 2 relay to the Line voltage
input of the Bus Tie relay and connect this circuit to a voltage source (Source 2
for these tests). Do not energize the source.
8. Assert Logic Input 5 (Breaker Connected) at the Bus Tie relay; Output Relays 4
and 6 on the Bus Tie relay should operate.
9. Assert Logic Input 5 (Breaker Connected) at the Incomer 1 relay - nothing
should happen.
10. Assert Logic Input 2 (Remote Close) at the Incomer 1 relay - nothing should
happen. Energize Source 1 at nominal voltage - the Incomer 1 breaker should
http://www.GEmultilin.com
Feeder Management Relay
.
to 0.
UNDERFREQ RESTORE MIN VOLTS
to 0.
setpoint.
750/760
level into the bus
7–53