ABB VM1 Installation And Service Instructions Manual page 56

VM1 - USER MANUAL
56
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11. Maintenance
11.3.3. Circuit breaker pole
The circuit breaker pole and relative vacuum
interrupter are maintenance-free up to the
maximum number of
electrical operations foreseen for the type of
interrupter (see par. 9.2. Trip curves).
The operating life of the vacuum interrupter is
defined by the sum of the ultimate currents
corresponding to the specific type of interrupter
in accordance with what is indicated in the graphs
of par. 9.2. Trip curves: when the sum of the
ultimate currents is reached, the complete pole
must be replaced.
Note
Dismantling and replacement of the pole can only be carried out by ABB
personnel or suitably qualified and specially trained personnel, especially
for the necessary adjustments.
To carry out the interrupter test without
dismantling the circuit breaker pole, use:
• the VIDAR vacuum tester, made by the company
Programma Electric GmbH, Bad Homberg v.d.H.
To check vacuum tightness of the interrupter, the
following test values must be set on the VIDAR
tester:
Rated voltage of the circuit breaker
12 kV
17.5 kV
24 kV
The test must always be carried out with the
circuit breaker open with the contacts at the
nominal distance (12 to 24 kV).
Procedure for testing the degree of vacuum of the
interrupter of the circuit breaker poles:
• turn the power supply off and make the working
area safe by following the safety regulations
specified in the IEC/DIN VDE Standards;
• open the circuit breaker;
• earth a terminal of each circuit breaker pole;
• connect the earthed terminal of the VIDAR tester
to the circuit breaker structure;
• connect the high voltage terminal of the VIDAR
tester to the terminal of the circuit breaker pole
not connected to earth (L1 phase) and carry out
the test. Repeat the test for phases L2 and L3.
Note
The tester connection cables can produce an indication due to the
capacitive effect. In this case the cables must not be removed.
11.4. Repairs
Replacement of spare parts and accessories must
only be carried out by ABB personnel or suitably
qualified and specially trained personnel.
Always work with the circuit breaker open and
locked so that it cannot be closed again, with the
work area insulated and made safe.
The drive springs must be discharged.
All power supply sources must be disconnected
and made safe against any reclosing during
removal and installation work.
DC test voltage
40 kV
40 kV
60 kV
Should maintenance be carried out by the
customer's personnel, responsibility for
the interventions remains with the
customer.
The replacement of parts not included in
the "List of spare parts/accessories" (par.
13.1.) must only be carried out by ABB
personnel. In particular:
• complete pole with bushings/
connections
• actuator
• transmission system.