GE Feeder Management Relay 750 User Manual

8-30 750/760 Feeder Management Relay GE Multilin
8.4 PROTECTION SCHEMES 8 COMMISSIONING TESTS
8
The following procedure tests the Underfrequency Pickup:
1. Inject voltage at a frequency above the pickup level into phase V
a
. Slowly decrease the frequency until the Pickup LED
comes on. Note the pickup value.
2. Slowly increase the frequency until the Pickup LED goes out. Note the dropout level, which should be the pickup plus
0.03 Hz.
The following procedure tests Blocking From Logic Inputs:
1. Inject voltage and current above minimum at a frequency to cause a pickup.
2. Assert a logic input to provide a "Block Underfreq 1 (2)". The Pickup LED should immediately go out.
3. Repeat Steps 1 and 2 for logic input “Block 1 Trip Relay” as required.
The following procedure tests the Underfrequency element Timing:
1. Connect the “Stop Trigger".
2. Set the voltage source prefault mode to nominal voltage, current and frequency.
3. Set the voltage source fault mode to nominal voltage and current, but with a frequency below pickup.
4. Set the source to prefault mode, reset the timer, and apply to the relay.
5. Jump the source to fault mode and measure the operating time.
6. Repeat Steps 4 and 5 four more times and obtain an average of the time intervals.
7. Reset the relay and disconnect the “Stop Trigger".
b) FREQUENCY DECAY
To test Frequency Decay, use 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 Indications and Operations are as outlined for Phase TOC 1
on page 8–16.
The following procedure checks Minimum Operating Voltage Supervision:
1. Inject voltage into the V
a
bus voltage input at a level well below the Minimum Operating Voltage level. Also inject I
a
= I
b
= I
c
at a level well above the Minimum Operating Current level. Starting with the V
a
frequency at a level well below the
FREQ DECAY PICKUP, drop the frequency of V
a
at a speed greater than the FREQ DECAY RATE setting. The pickup indi-
cator should remain off.
2. Inject voltage into the V
a
bus voltage input at a level well above the Minimum Operating Voltage level. Also inject I
a
= I
b
= I
c
at a level well above the Minimum Operating Current level. Starting with the V
a
frequency at a level well below the
FREQ DECAY PICKUP, drop the frequency of V
a
at a speed greater than the FREQ DECAY RATE setting. The pickup indi-
cator should come on while the V
a
frequency is dropping.
The following procedure checks the Minimum Operating Current Supervision:
1. Inject voltage into the V
a
bus voltage input at a level well above the Minimum Operating Voltage level. Also inject I
a
= I
b
= I
c
at a level well below the Minimum Operating Current level. Starting with the V
a
frequency at a level well below the
Frequency Decay Pickup, drop the frequency of Va at a speed greater than the Frequency Decay Rate setting. The
Pickup LED should remain off.
2. With the V
a
voltage at a level well above the Minimum Operating Voltage level, increase I
a
to a level well above the
Minimum Operating Current level. Currents I
b
and I
c
should be well below the Minimum Operating Current level. Start-
ing with the V
a
frequency at a level well below the FREQ DECAY PICKUP, drop the frequency of V
a
at a speed greater
than the
FREQ DECAY RATE setting. The Pickup LED should come on while the V
a
frequency is dropping.
3. With the V
a
voltage at a level well above the Minimum Operating Voltage level, increase I
b
to a level well above the
Minimum Operating Current level. Currents I
a
and I
c
should be well below the Minimum Operating Current level. Start-
ing with the V
a
frequency at a level well below the FREQ DECAY PICKUP, drop the frequency of V
a
at a speed greater
than the
FREQ DECAY RATE setting. The Pickup LED should come on while the V
a
frequency is dropping.
4. With the V
a
voltage at a level well above the Minimum Operating Voltage level, increase I
c
to a level well above the
Minimum Operating Current level. Currents I
a
and I
b
should be well below the Minimum Operating Current level. Start-
ing with the V
a
frequency at a level well below the FREQ DECAY PICKUP, drop the frequency of V
a
at a speed greater
than the
FREQ DECAY RATE setting. The Pickup LED should come on while the V
a
frequency is dropping.
Courtesy of NationalSwitchgear.com

GE Feeder Management Relay 750 Specifications

General

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