ABB V-Contact VSC Series User Manual

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7.5. Servicing following a short-circuit
or overload
General
It is foreseen that the VSC contactor be protected by power
fusesand/orbyacircuit-breaker.Inanycase,thevalueof
a short-circuit can exceed the threshold of damage to the
vacuum bottles.
After interruption of a short-circuit at the maximum rated
MVAofthecontactor,putthecauseofthefaultright,inspect
all the apparatus and carry out the repairs or replacements
necessary before putting the apparatus back into service.
Makesurethatallthespareparts(whenrequired)aresuitable
for the application.
Incaseofanydoubts,pleasecontactABB.
Have a complete check of the contactor
carried out by ABB personnel after 1,000,000
operations or 10 years of operation.
Contact ABB Service Assistance.
Vacuum interrupters
A dielectric test by itself cannot be confirmation that the
interrupters have to be put back into service after a fault.
However,ifthereisnophysicalsignofstressandifthe
distanceMexceedsaminimumof0.5mm,theinterrupters
can be tested dielectrically as mentioned in point 3 of table 4.
Shouldthistestalsobepositive,itisreasonabletoputthe
interrupters back into service following a fault.
Enclosures
External evidence of deformation of the enclosure is usually
indicative of damage inside it. Extensive damage will require
replacement of the enclosure parts and of the apparatus
contained in it.
Terminals and internal conductors
Replacethedamagedpartswhichshowdiscolouration,
melting or damage caused by electric arcs.
Pay special attention to the moving parts.
Carry out the “Checking” procedures indicated in par. 6. of
this manual before putting the apparatus back into service.
7.6. Repairs
Replacement with spare parts and accessories must only
be carried out by ABB personnel or by suitably qualified
personnel with appropriate training.
All the power supply sources must be turned off and the
capacitor must be discharged.
Alwaysworkwiththecontactoropen,withtheworkarea
insulated and made safe.
Should maintenance be carried out by the
customer’s personnel, responsibility for the
interventions lies with the customer.
Item to be serviced Interval Operation to be carried out
1 Contactor. 2 years or
100,000operations.
Carry out five mechanical closing and opening operations. The contactor must operate
regularly without stopping in intermediate positions.
2 Contactor springs. 2 years or
100,000operations.
Check integrity of the springs.
3
Power connections. 2 years or
100,000operations.
Check tightness: M8 bolt = 23 Nm; M10 bolt = 33 Nm.
Check there are no traces of overheating or oxidation.
4
Earthing contact
(fixedcontactors)
2 years or
100,000operations.
Check tightness of the connections.
5
Insulation resistance. 2 years or
100,000operations.
See par. 6.1.
6
Racked-in/isolated
auxiliary contacts in the
truck.
2 years or
100,000operations.
Check that the signals are correct.
Furthermore provide: – replacementoftheauxiliarycontactsafter250,000operations.
7.4. Servicing
Carry out the checks described below.
NEPSI.COM - Northeast Power Systems. Inc.

ABB V-Contact VSC Series Specifications

General

Brand	ABB
Model	V-Contact VSC Series
Category	Industrial Electrical
Language	English