GE Digital Energy Multilin 239, Инструкция по эксплуатации

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CHAPTER 7: TESTING
239 MOTOR PROTECTION RELAY – INSTRUCTION MANUAL 7–99
7.3 Phase Current Accuracy
Any phase current protection is based on the ability of the 239 to read phase input
currents accurately to ±2% of full scale. Perform the steps below to test the phase
current accuracy.
1. Alter the following setpoint.
S2: SYSTEM SETUP\CT INPUTS\PHASE CT PRIMARY: 100A
2. To determine if the relay is reading the proper input current values, inject phase
currents shown in the table below, view the readings in
A2: METERING\CURRENT
,
and verify with the expected readings stated in the table.
3. Alter the setup to inject current into the 1 A input of each phase and repeat the above
step with current settings shown in the table below.
Table 7–1: Phase Current Accuracy Test, 5 A Input
INJECTED
CURRENT
EXPECTED READING
IN EACH PHASE †
ACTUAL PHASE A
READING (A)
ACTUAL PHASE B
READING (A)
ACTUAL PHASE C
READING (A)
0.5 A 10 A
1.0 A 20 A
3.5 A 70 A
5.0 A 100 A
10.0 A 200 A
† displayed current injected current
PHASE CT PRIMARY
5 A
------------------------------------------------
 
 
×
=
Table 7–2: Phase Current Accuracy Test, 1 A Input
INJECTED
CURRENT
EXPECTED READING
IN EACH PHASE †
ACTUAL PHASE A
READING (A)
ACTUAL PHASE B
READING (A)
ACTUAL PHASE C
READING (A)
0.1 A 10 A
0.3 A 30 A
0.6 A 60 A
1.0 A 100 A
2.0 A 200 A
† displayed current injected current PHASE CT PRIMARY
×
=