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4 Maintenance
Closing of the switch several times under load
conditions (maximum two closing operations at
100 % of the rated short-circuit making current)
makes inspection and possibly maintenance
necessary. The electrical and mechanical
functions of the switch must not be adversely
affected, and only slight contact welding is
permissible. The pairs of earthing blades and
the earthing contacts should be replaced if
necessary.
Otherwise, it is advisable to carry out inspection
and maintenance of the earthing switches at
appropriate intervals together with the switchgear,
particularly in exceptional operating conditions
and/or under adverse environmental influences
such as pollution and aggressive air.
•
Check whether the operating mechanism
functions smoothly and easily
•
Carry out general visual examination for the
condition of mechanical fasteners, dirt, moisture
and corrosion
•
Remove any dust deposits on insulating parts
with a dry, soft cloth (do not use cleaning wool)
•
Regrease the mechanically movable parts and
contacts (applying grease thinly) using Isoflex
Topas NB 52 lubricant
8
ST-E EARTHING SWITCH
I N S T R U C T I O N M A N U A L
Summary of Contents for ST-E Series
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