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6.17.2.2 Information
F#
LCD-Text
Failure Σ I
0162
0163
Fail I balance
0167
Fail V balance
0171
Fail Ph. Seq.
0175
Fail Ph. Seq. I
0176
Fail Ph. Seq. V
0161
Fail I Superv.
0197
MeasSup OFF
6509
>FAIL:FEEDER VT
6510
>FAIL: BUS VT
6.17.3 Description of Fuse-Failur-Monitor
Single-Phase Mea-
surement Voltage
Loss or Fuse Fail-
ure Monitoring
7SJ63 Manual
C53000-G1140-C120-1
Failure: Current Summation
Failure: Current Balance
Failure: Voltage Balance
Failure: Phase Sequence
Failure: Phase Sequence Current
Failure: Phase Sequence Voltage
Failure: general Current Supervision
Measurement Supervision is switched OFF
>Failure: Feeder VT
>Failure: Busbar VT
In the event of a loss of measured voltage on one phase (typically due to a short circuit
or broken conductor in the voltage transformer secondary circuit), the device will false-
ly detect zero voltage. False detection of zero voltage can cause problems with the
directional overcurrent protection and the undervoltage protection.
If fuses are used instead of a secondary miniature circuit breaker with connected aux-
iliary contacts, then the fuse failure monitoring can detect problems in the voltage
transformer secondary circuit. If phase-to-phase voltages and the displacement volt-
age are supplied to the system, then the fuse failure monitor is masked. Of course,
supervision of the miniature circuit breaker and the fuse failure monitor can be used
at the same time.
If zero sequence voltage occurs, without a ground current being measured at the
same time, the device concludes that an unsymmetrical fault has occurred in the volt-
age transformer secondary circuit. The processing of the displacement voltage pro-
cessing of the sensitive ground fault detection and the undervoltage protection func-
tions are blocked.
Note:
For ungrounded systems or systems which generate small amounts of ground fault
current, fuse failure monitoring must not be used!
Comments
Functions
6-153
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