GE Feeder Management Relay 750 User Manual

8-28 750/760 Feeder Management Relay GE Multilin
8.4 PROTECTION SCHEMES 8 COMMISSIONING TESTS
8
6. Repeat Steps 1 through 4, substituting V
bn
for V
an
, V
cn
for V
bn
and V
an
for V
cn
.
The following procedure tests Pickup with Three Phases For Operation:
1. Inject V
an
= V
bn
= V
cn
= a voltage above the pickup voltage into the bus voltage input of the relay. The Pickup LED
should be on.
2. Slowly lower V
an
until the Pickup LED goes out. This reset voltage should be the pickup value minus 2% of VT.
3. Raise V
an
until the Pickup LED comes on. This is the pickup voltage of V
an
.
4. Slowly lower V
bn
until the Pickup LED goes out. This reset voltage should be the pickup value minus 2% of VT.
5. Raise V
bn
until the Pickup LED comes on. This is the pickup voltage of V
bn
.
6. Slowly lower V
cn
until the Pickup LED goes out. This reset voltage should be the pickup value minus 2% of VT.
7. Raise V
cn
until the Pickup LED comes on. This is the pickup voltage of V
cn
.
f) OVERVOLTAGE (DELTA VTS ONLY)
To test Overvoltage for Delta VTs, use the test connections specified in Figure 8–2: Relay Test Wiring – Delta Connection
on page 8–3. The following procedure tests Pickup with One Phase For Operation:
1. Inject V
ab
= V
cb
= 0 into the bus voltage input of the relay. The Pickup LED should be off.
2. Slowly raise V
ab
until the Pickup LED comes on. This is the pickup voltage.
3. Lower V
ab
until the Pickup LED goes out. This is the reset voltage, which should be the pickup value minus 2% of VT.
4. Repeat Steps 1 through 3 except adjust V
bc
.
The following procedure tests Pickup with Two or Three Phases For Operation:
1. Inject V
ab
= V
cb
> pickup into the bus voltage input. The Pickup LED should be on.
2. Lower V
ab
until the Pickup LED goes out. This is the reset voltage, which should be the pickup value minus 2% of VT.
3. Slowly raise V
ab
until the Pickup LED comes on. This is the pickup voltage.
4. Repeat Steps 1 through 3 except adjust V
bc
.
g) OVERVOLTAGE (WYE AND DELTA VTS)
To test Overvoltage for Delta and Wye VTs, use the test connections specified in Figure 8–1: Relay Test Wiring – Wye Con-
nection and Figure 8–2: Relay Test Wiring – Delta Connection on page 8–3. The Indications and Operations are as outlined
for Phase TOC 1 on page 8–16.
The following procedure tests Blocking From Logic Inputs:
1. Inject voltage to cause a pickup.
2. Assert a logic input to provide a "Block 1 Trip Relay".
The following procedure tests the element Timing:
1. Connect the “Stop Trigger".
2. Set the voltage source to the required test voltage, then turn off voltage.
3. Reset the timer. Turn the voltage on in the required number of phases, and measure the operating time. Repeat Steps
2 and 3 four more times and obtain an average of the time intervals.
4. Reset the relay and disconnect the “Stop Trigger".
h) NEUTRAL DISPLACEMENT (WYE VTS ONLY)
To test Neutral Displacement (Wye VTs only), use the test connections specified in Figure 8–1: Relay Test Wiring – Wye
Connection on page 8–3.
The following procedure tests the Pickup Level:
1. Apply a three phase balanced nominal voltage to the relay.
2. Reduce one phase voltage slowly until the Neutral Displacement element operates and note this voltage.
Courtesy of NationalSwitchgear.com

GE Feeder Management Relay 750 Specifications

General

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