GE KVGC 202 - 9.7.4 Undervoltage Blocking (V<<) Testing; 9.7.5 Circulating Current Detector (IC) Testing

Technical
Manual
KVCG202/EN M/H
11
KVGC202
- intertap delay (tINTER),
- load current (
IL)].
9.7.4 Undervoltage blocking (V<<)
The relay should be commissioned with the settings calculated for the application.
When the system voltage input falls below set value, the undervoltage blocking detector
operates and instantaneously resets the initial time delay thus inhibiting the relay outputs
to ‘Raise’ or ‘Lower’ tap change operations.
Before making the following changes note the settings for: initial time delay setting
(tINIT), intertap delay (tINTER), undervoltage blocking setting (V<<).
Set the:
- initial time delay setting (tINIT) to 10 seconds,
- intertap delay (tINTER) to 5 seconds,
- undervoltage blocking setting (V<<) 60V to 130V].
Set the relay output masks to operate undervoltage blocking contacts ‘V<<‘ and
undervoltage detector contacts ‘V<‘. Both contacts should be open.
Monitor ‘Raise volts’ should be open.
Apply 115% of system voltage to input (terminals 17 & 18).
The ‘CONTROL’ LED should illuminate and the ‘Raise volts’ relay contacts should close
for a period of tPULSE. The undervoltage detector contacts ‘V<‘ should be closed.
Slowly reduce the input voltage until the ‘V<<‘ contacts closes simultaneously with the
opening of the ‘Raise volts’ contacts. ‘V<blk’ should be displayed on the LCD.
Check the voltage at which the tap change is cancelled is in the range. (V<<) –5% of
setting. Both ‘Raise volts’ and ‘Lower volts’ relay contacts should be open. The
‘CONTROL LED’ should be permanently lit and the ‘Blocked’ relay contacts should be
closed.
Restore the following settings:
- initial time delay setting (tINIT),
- intertap delay (tINTER),
- undervoltage blocking setting (V<<)].
9.7.5 Circulating Current Detector (
I
C
)
The relay should be commissioned with the settings calculated for the application.
This test will check if both the ‘Raise’ and ‘Lower’ operations of the relay are internally
blocked when the circulating current exceeds the set value if logic link LOG2 is set to ‘1’.
This also causes an alarm output either instantaneously or with a definite time delay.
Set the relay mask to operate ‘
Ic>’ and ‘Blocked’ relay output contacts. Both relay
contacts should be open.
Before making the following changes note the settings for: logic link LOG2, initial time
delay setting (tINIT), intertap relay (tINTER), circulating current setting (
Ic), Excessive
circulating current time delay (t
Ic).
Set the:
- logic link LOG2 to ‘0’,
- initial time delay setting (tINIT) to 0 seconds,
- intertap delay (tINTER) to 0 seconds,