GE 750 Instruction Manual page 441

17 COMMISSIONING
8. Lower V until the PICKUP indicator goes out. This is the programmed Minimum Operating Voltage of V
an
minus 2% of VT.
9. Slowly raise V until the PICKUP indicator comes on. This is the Minimum Operating Voltage level.
an
10. Reduce V until the PICKUP indicator goes out. This is the programmed Minimum Operating Voltage of
bn
V
minus 2% of VT.
bn
11. Slowly raise V until the PICKUP indicator comes on. This is the Minimum Operating Voltage level.
bn
12. Reduce V until the PICKUP indicator goes out. This is the programmed Minimum Operating Voltage of
cn
V minus 2% of VT.
cn
13. Slowly raise V until the PICKUP indicator comes on. This is the Minimum Operating Voltage level.
cn
b) FOR DELTA VTs
Test Connections per Figure 17–2: RELAY TEST WIRING – DELTA CONNECTION on page 17–4.
Pickup with One Phase For Operation:
1. Inject V = V
= nominal voltage into the bus voltage input of the relay. The PICKUP indicator should be
ab cb
off.
2. Slowly lower V
ab
3. Continue to lower V
2% of VT.
4. Raise V
until the PICKUP indicator comes on, and continue to increase until the indicator goes out. This
ab
is the reset voltage, which should be the pickup value plus 2% of VT.
5. Repeat steps 1 through 4 except adjust V
Pickup with Two or Three Phases For Operation:
1. Inject V = nominal voltage and V
ab
voltage into the bus voltage input of the relay. The PICKUP indicator should be on.
2. Slowly raise V until the PICKUP indicator goes out. This is the reset voltage, which should be the pickup
cb
value plus 2% of VT.
3. Reduce V until the PICKUP indicator comes on. This is the pickup voltage of V
cb
4. Continue to lower V
Voltage of V minus 2% of VT.
cb
5. Slowly raise V until the PICKUP indicator comes on. This is the Minimum Operating Voltage level.
cb
6. Reduce V until the PICKUP indicator goes out. This is the programmed Minimum Operating Voltage of
ab
V
minus 2% of VT.
ab
7. Slowly raise V
ab
which should be the pickup value plus 2% of VT.
8. Lower V until the PICKUP indicator comes on. This is the pickup voltage of V
ab
GE Power Management
Courtesy of NationalSwitchgear.com
until the PICKUP indicator comes on. This is the pickup voltage.
until the PICKUP indicator goes out. This is the Minimum Operating Voltage minus
ab
.
bc
= a voltage between the Minimum Operating Voltage and the pickup
cb
until the PICKUP indicator goes out. This is the programmed Minimum Operating
cb
until the PICKUP indicator first comes on and then goes out. This is the reset voltage,
750/760 Feeder Management Relay
17.7 PROTECTION SCHEMES
.
cb
.
ab
an
17
17-
35