Secondary Circuits - TAVRIDA ELECTRIC VCB Series User Manual

7.2 Secondary circuits

The CM is inherently maintenance free. However when maintenance is carried out on the switchgear then
commissioning tests should be repeated. It is also recommended to conduct regular visual checks of the
module housing and insulation of the wires connected to the CM. Test results should be treated as given in
the Table 19.
Operation description
Connect all points of the secondary circuits
with a shorting wire. ISM coil connection
wires must be disconnected from connector
X3 of the CM before the test.
Connect the shorting wire to the high
potential lead of the high voltage tester and
ground the circuit breaker housing. Start
with zero volts, gradually increase the test
voltage to 1500 V RMS, 50 or 60 Hz.
Maintain test voltage for one minute.
If no disruptive discharge occurs, the
secondary circuits insulation level is
satisfactory.
Disconnect the shorting wire and reattach
the wires to connector X3 of the CM.
Table 19 - List of tests and check-ups of CM during maintenance
Required tool
Auxiliary circuits insulation check
Wires
Power frequency withstand voltage test set
Power frequency withstand voltage test set
Visual check, no tool is required
Approximate timing
5 minutes
3 minutes
-
5 minutes
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