9.1 Strategies
9.1.1 Preventive maintenance
Is maintenance carried out at predetermined
intervals or according to prescribed criteria, aimed
at reducing the failure risk or performance
degradation of the equipment.
This method is based on scheduled activities
performed on the out-of-service equipment
including: visual checks, apparatus cleaning,
mechanical components lubrication, worn parts
replacement and routine tests.
9.1.2 Risk-based maintenance
Is maintenance carried out by integrating analysis,
measurement and periodic test activities with
standard preventive maintenance.
The gathered information is viewed in the context
of the environmental, operation and process
condition of the equipment in the system. The
aim is to perform the asset condition and risk
assessment and define the appropriate
maintenance tasks.
9.2 Inspection
Caution!
The switchgear should first be
de-energised in accordance with the site
procedures and the recommendations in
the ZVC Operating Manual.
The checks listed below must be carried
out by ABB personnel or suitably
qualified client staff.
During normal service the contactors are
maintenance-free.
The frequency of inspection will depend on service
conditions including frequency of operations,
the value of the interrupted current, the power
factor and installation ambient.
It is strongly advisable to keep a maintenance
card and service book for each unit where the
anomaly and the corrective action are listed with
dates. These records are invaluable in case of
investigations of later events on the switchgear.
—
9 Maintenance
M A I N T E N A N C E
45