CHAPTER 7: TESTING
489 GENERATOR MANAGEMENT RELAY – INSTRUCTION MANUAL 7–13
7.3.2 Power Measurement Test
The specification for reactive and apparent power is ± 1% of × 2 × CT × VT
ratio
× VT
full-
scale
at I
avg
< 2 × CT. Perform the steps below to verify accuracy.
Z In the
S2 SYSTEM SETUP Z CURRENT SENSING menu, set:
PHASE CT PRIMARY: “1000”
Z In the S2 SYSTEM SETUP ZV VOLTAGE SENSING menu, set:
VT CONNECTION TYPE: “Wye”
VOLTAGE TRANSFORMER RATIO: “10.00:1”
Z Inject current and apply voltage as per the table below.
Z Verify accuracy of the measured values.
Z View the measured values in the
A2 METERING DATA ZV POWER
METERING menu:
7.3.3 Reactive Power Accuracy
The specification for reactive power is ±1% of × 2 × CT × VT
ratio
× VT
full scale
at
I
avg
< 2 × CT. Perform the steps below to verify accuracy and trip element.
Z In the
S2 SYSTEM SETUP Z CURRENT SENSING menu, set:
PHASE CT PRIMARY: “5000”
Z In the S2 SYSTEM SETUP ZV VOLTAGE SENSING menu, set:
VT CONNECTION TYPE: “Wye”
VOLTAGE TRANSFORMER RATIO: “100:1”
Z In the S2 SYSTEM SETUP ZV GEN. PARAMETERS menu, set
GENERATOR RATED MVA: “100”
GENERATOR RATED POWER FACTOR: “0.85”
GENERATOR VOLTAGE PHASE-PHASE: “12000”
The rated reactive power is .
Z Alter the following reactive power setpoints in the
S7 POWER ELEMENTS
Z REACTIVE POWER menu:
Injected Current / Applied Voltage
(Ia is the reference vector)
Power Quantity Power Factor
1 A UNIT 5 A UNIT Expected Tolerance Measured Expected Measured
Ia = 1 A∠0°
Ib = 1 A∠120° lag
Ic = 1 A∠240° lag
Va = 120 V∠342° lag
Vb = 120 V∠102° lag
Vc = 120 V∠222° lag
Ia = 5 A∠0°
Ib = 5 A∠120° lag
Ic = 5 A∠240° lag
Ia = 120 V∠342° lag
Vb = 120 V∠102° lag
Vc = 120 V∠222° lag
+3424 kW
3355 to
3493 kW
0.95 lag
Ia = 1 A∠0°
Ib = 1 A∠120° lag
Ic = 1 A∠240° lag
Va = 120 V∠288° lag
Vb = 120 V∠48° lag
Vc = 120 V∠168° lag
Ia = 5 A∠0°
Ib = 5 A∠120° lag
Ic = 5 A∠240° lag
Va = 120 V∠288° lag
Vb = 120 V∠48° lag
Vc = 120 V∠168° lag
+3424 kvar
3355 to
3493 kvar
0.31 lag
100 cos
1–
0.85()()sin 52.7 Mvar±=
Courtesy of NationalSwitchgear.com