Siemens SINOVA - Inspection & Maintenance; General Principles, Safety, and Personnel

3WJ Air Circuit breakers
Operating Instructions, 12/2022, L1V30828903001-01
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Inspection & Maintenance
4
4.1 General
In addition to the costs of purchasing the protection devices and power distribution
equipment, the expenditure associated with service and maintenance are a significant cost
and time factor for the operator.
• Inspection:
Inspection refers to visual inspection of the circuit breaker and testing of the electrical and
mechanical functions of the circuit breaker.
• Maintenance:
If a defect or problem becomes apparent during the inspection, the circuit breaker must
be subjected to a maintenance procedure. During maintenance, parts can be replaced,
wiring can be changed or secured, and installed or fitted parts can be refastened.
The following factors have an impact on expenditure and downtimes:
1. Time between inspection intervals
The operator defines the inspection intervals based on the operating conditions of the
circuit breaker. In normal operation, the circuit breaker must be inspected at least once a
year. If certain conditions are met, the inspection interval can be extended to four years.
For more information, see Chapter Inspection interval.
2. Scope of work, tests and checks to be performed
Only inspections are required for the 3WJ circuit breaker.
For more information on the scope of the inspections, see Chapter Planning of
inspection and maintenance.
3. Number and frequency of components and accessories requiring replacement
Parts only need to be replaced during maintenance:
– If this is deemed necessary based on the inspection results
– When the contacts of the circuit breaker have reached their specified service life and
require replacement
– When the circuit breaker has reached the maximum number of operating cycles
without maintenance
Provided the specified operating conditions are observed, the service life of the accessory
components corresponds to the maximum mechanical service life of the 3WJ circuit
breaker.
The 3WJ circuit breaker can be operated at low cost. Among other things, no relubrication
of moving parts is necessary thanks to its grease reserves.