Woodward HighPROtec MCDLV4, Manual

Page: 1079 / 1275

Supervision
Commissioning: Current Transformer Failure Supervision
Precondition:
1. Measurement of all three phase currents (are applied to the
measuring inputs of the device).
2. The earth current is detected via a cable-type transformer (not in
Holmgreen connection).
Object to be tested
Check of the CT supervision (
by comparing the calculated with the measured earth current) .
Necessary means
Three-phase current source
Procedure, part 1
Set the limiting value of the CTS to »delta I=0.1*In«.
Feed a three-phase, symmetrical current system (approx. nominal current) to the secondary side.
Disconnect the current of one phase from one of the measuring inputs (the symmetrical feeding at
secondary side has to be maintained).
Make sure that the signal
»CTS.A
LARM
« is generated now.
Successful test result, part 1
The signal
»CTS.A
LARM
«
is generated.
Procedure, part 2
Feed a three-phase, symmetrical current system (approx. nominal current) to the secondary side.
Feed a current that is higher than the threshold value for the measuring circuit supervision to the earth
current measuring input.
Ascertain that the signal
»CTS.A
LARM
«
is generated now.
Successful test result, part 2
The signal »CTS.A
LARM
« is generated.
1079 MCDLV4 DOK-HB-MCDLV4-2E