EMR-5000
IM02602012E
Commissioning: Current Transformer Failure Supervision
Preconditions:
1.Measurement of all three-phase currents (are applied to the measuring inputs
of the device).
2.The ground current is detected via a zero sequence transformer (not in
residual connection).
Object to Be Tested:
Check of the CT Supervision (
by comparing the calculated with the measured ground 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 the secondary side
has to be maintained).
•
Make sure that the »CTS.A
LARM
« signal is generated.
Successful Test Result, Part 1:
The
»CTS.A
LARM
«
signal 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 ground current
measuring input.
Make sure that the
»CTS.A
LARM
«
signal is generated.
Successful Test Result, Part 2:
The »CTS.A
LARM
« signal is generated.
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