9229 9923 176 0B
Maintenance and servicing
High voltage – danger to life
Touching live parts is fatal or causes serious physical injury.
Before beginning maintenance work, note the five safety rules for high-voltage
equipment specified in EN 50110-1, namely:
Isolate from the power supply*)
Secure against reclosing
Verify safe isolation from the power supply
Earth and short-circuit
Cover or cordon off neighbouring live parts
On the vacuum circuit-breaker, actuate the OPEN, CLOSE and OPEN pushbut-
tons manually one after the other. This ensures that the vacuum circuit-breaker is
open and the closing spring is discharged.
The vacuum circuit-breaker module should be taken out of the switch cabinet or
switchgear for servicing.
The 3AKvacuum circuit-breaker module is maintenance-free under normal operat-
ing conditions. We do, however, recommend you carry out regular visual inspec-
tions. The maximum permitted mechanical operating cycle number is 10 000.
The insulating parts must be clean if their insulating capacity is to be guaranteed.
Rub insulating parts with a moist cloth.
As a cleaning agent, use only warm water with a mild, liquid household detergent
added and leave to dry.
Joints and bearings that cannot be disassembled must not be washed out with a
detergent prior to work.