GE Feeder Management Relay 750 User Manual

8-20 750/760 Feeder Management Relay GE Multilin
8.4 PROTECTION SCHEMES 8 COMMISSIONING TESTS
8
For forward tripping and Wye connected VTs, use the test connections specified in Figure 8–1: Relay Test Wiring – Wye
Connection on page 8–3 and use the following procedure:
1. Set V
an
= V
bn
= V
cn
> MIN POLARIZING VOLTAGE setpoint at 0°, 120°, and 240°, respectively. Inject Phase A current of
0.2 x CT at an angle which is in phase with the polarizing voltage. This angle is outside the tripping region, so tripping
should be blocked. If the function is set to “Control”, check that any output relays programmed for this condition are
operated. If the function is set to “Alarm”, check that the Alarm and Message LEDs are flashing, the correct Phase
Directional Reverse alarm message is displayed, and any output relays programmed for this condition are operated.
2. Slowly increase the angle of the Phase A current in the lagging direction. The directional element should detect current
flow in the tripping direction when the Phase A current is lagging the polarizing voltage by more than 90° ±2°. The
alarm and output relays should reset.
3. Continue to increase the lagging angle until the alarm is again raised. The Phase A current should be lagging the
polarizing voltage by an angle of 270° ± 2°.
4. Continue to increase the angle until the Phase A current is once again in phase with the polarizing voltage. The alarm
should remain.
5. Repeat the above Steps 1 through 4 for current angle adjusted in each of Phases B and C.
For forward tripping and Delta connected VTs, use the test connections specified in Figure 8–2: Relay Test Wiring – Delta
Connection on page 8–3 and use the following procedure:
1. Set V
ab
= V
bc
= V
ca
> MIN POLARIZING VOLTAGE setpoint at 0°, 120°, and 240°, respectively. Inject Phase A current of
0.2 x CT at an angle which is in phase with the polarizing voltage. This angle is outside the tripping region, so tripping
should be blocked. If the function is set to “Control”, check that any output relays programmed for this condition are
operated. If the function is set to “Alarm”, check that the Alarm and Message LEDs are flashing, the correct Phase
Directional Reverse alarm message is displayed, and any output relays programmed for this condition are operated.
2. Slowly increase the angle of the Phase A current in the lagging direction. The directional element should detect current
flow in the tripping direction when the Phase A current is lagging the polarizing voltage by more than 90° ±2°. The
alarm and output relays should reset.
3. Continue to increase the lagging angle until the alarm is again raised. The Phase A current should be lagging the
polarizing voltage by an angle of 270° ±2°.
4. Continue to increase the angle until the Phase A current is once again in phase with the polarizing voltage. The alarm
should remain.
5. Repeat the above Steps 1 through 4 for current angle adjusted in each of Phases B and C.
8.4.3 NEUTRAL OVERCURRENT
a) NEUTRAL TOC 1
The procedure to test this element is identical to that outlined in Phase TOC 1 on page 8–16, except that current is injected
into any one phase, and the element is not subject to the “phases required for operation” and “voltage restrained time over-
current” tests.
The blocking from logic inputs check is different from that for Phase TOC 1 and is performed as follows:
1. Inject current to cause a pickup.
2. Assert logic input to provide a "Block Neutral Time 1". The Pickup LED should immediately turn off.
3. Repeat Steps 1 and 2 for logic inputs "Block Neutral O/C", "Block All O/C" and “Block 1 Trip Relay” as required.
b) NEUTRAL TOC 2
The procedure to test this element is identical to that outlined in Phase TOC 1 on page 8–16, except that current is injected
into any one phase, and the element is not subject to the “phases required for operation” and “voltage restrained time over-
current” checks.
The blocking from logic inputs check is different from that for Phase TOC 1 and is performed as follows:
1. Inject current to cause a pickup.
2. Assert logic input to provide a "Block Neutral Time 2". The Pickup LED should immediately go out.
Courtesy of NationalSwitchgear.com

GE Feeder Management Relay 750 Specifications

General

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