GE Feeder Management Relay 750 User Manual

8-10 750/760 Feeder Management Relay GE Multilin
8.3 METERING 8 COMMISSIONING TESTS
8
8.3METERING 8.3.1 CURRENT METERING
a) PHASE CURRENT INPUTS
For these tests, refer to the figures on page 8–3 for test connections. The expected accuracy is as follows:
For 1 A CTs: ±0.01 A for 0.01 to 1.99 A; ±0.2 A for 2.00 to 20.00 A
For 5 A CTs: ±0.05 A for 0.05 to 9.99 A; ±1.0 A for 10.00 to 100.00 A
Use the following procedure to test Phase and Neutral Current Inputs:
1. The relevant actual values displays are located under subheading
A2 METERING ÖØ CURRENT and are:
A: B: C: (Magnitude)
AVERAGE CURRENT: (Magnitude)
PHASE A CURRENT: (Phasor)
PHASE B CURRENT: (Phasor)
PHASE C CURRENT: (Phasor)
NEUTRAL CURRENT: (Phasor)
POS SEQ CURRENT: (Phasor)
NEG SEQ CURRENT: (Phasor)
ZERO SEQ CURRENT: (Phasor)
2. Inject 1-phase current of various values into the relay phase current input one phase at a time, and observe the magni-
tude. Note that the average, positive-sequence, negative-sequence and zero-sequence magnitudes are 1/3 of the
phase current magnitude for this test. The neutral current will match the phase current magnitude.
3. Inject 3-phase current of various values and angles into the relay phase current input and note the measured current
phasors and symmetrical components.
Use the following procedure for Ground and Sensitive Ground Current Inputs:
The relevant actual values displays are located under subheading A2 METERING ÖØ CURRENT as follows:
GND CURRENT: (Phasor)
SENSTV GND CURRENT: (Phasor)
1. Inject current of various values into the relay ground input, Terminals G10–H10, and note the current.
2. Inject current of various values into the relay sensitive ground input, Terminals G3–H3, and note the current.
b) PERCENT OF LOAD-TO-TRIP
For these tests, refer to the figures on page 8–3 for test connections. The expected accuracy is as follows:
Expected Accuracy: equivalent to that of phase current inputs
The relevant actual values displays are shown below:
A2 METERING ÖØ CURRENT ÖØ % OF LOAD-TO-TRIP
Percent of load-to-trip is calculated from the phase with the highest current reading. It is the ratio of this current to
the lowest pickup setting among the phase time and instantaneous overcurrent protection features. If all of these
features are disabled, the value displayed will be "0".
1. Inject current of various values into Phase A.
2. Verify that percent load-to-trip is calculated as the correct percentage of the most sensitive operational Phase Overcur-
rent element and displayed.
3. Repeat for phases B and C.
8.3.2 VOLTAGE METERING
a) BUS VOLTAGE
For these tests, refer to the figures on page 8–3 for test connections. The expected accuracy is as follows:
Phase-neutral voltages: ±0.68 V for 50 to 130 V; ±2.18 V for other voltages within specified limits
Phase-phase voltages (V
ab
and V
cb
): ±0.68 V for 50 to 130 V; ±2.18 V for all other voltages within the specified limits.
Phase-phase voltages (calculated V
ac
): ±1.36 V for 50 to 130 V; ±4.36 V for other voltages within the specified limits.
NOTE
Courtesy of NationalSwitchgear.com

GE Feeder Management Relay 750 Specifications

General

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