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2021-07-15 / V1.0
Maintenance
Contactors C320K/C320S – Installation and Maintenance Manual
8. Maintenance
Note the expert knowledge which is essential for car-
rying out maintenance work, referred to in chapter
“2. General and safety information”
.
8.1 Safety
DANGER
The contactors are used for high voltage switching. Contact with live electrical parts can result in
serious injuries or even death!
Live parts are all metal parts belonging directly to one of the circuits or wires connecting to them.
All other visible metal parts and wiring may also be live if a fault exists.
Before starting any work on the contactors, always comply with the following safety rules:
X
Disconnect on all sides
X
Secure to prevent switching back on
X
Clearly identify the working area
X
Check that a voltage-free state exists
X
Earth and short circuit; this includes discharging any capacitors in the main circuit
X
Besides the main power circuits, also disconnect additional and auxiliary circuits
X
Cover or insulate adjacent live parts
X
The presence of a voltage-free state can only be clearly identified by a qualified electrician.
X
When the work has been concluded, follow the procedure in reverse.
8.2 Preventive maintenance
Contactors of the C320 series are maintenance-free
within the rated mechanical life time. The electrical life
time depends on the number of switching cycles under
heavy load conditions and may vary for different ap-
plications. In normal use, this corresponds to a decade-
long operating period.
Intervals for regular tests/checks
To ensure the correct function and a prolonged opera-
tional life span of the contactors, the following checks
and maintenance must be regularly performed.
Test/check
Interval
External visual inspection of the
contactor
X
1x per year
Check of the main contacts (both,
stationary and moving contacts)
X
1x to 2x
per year
Checking of the auxiliary switches
X
Every 2 years
If the contactors are operated in a particularly dirty
environment, the visual checks should be performed
at shorter intervals. Dirt can impair the clearance and
creepage distances, which can result in a shorter ser-
vice life or to a malfunction.
Extraordinary checks need only be carried out if there
has been a significant and extraordinarily high record-
ed number of switching cycles under short-circuit con-
ditions.
DANGER
If damage to the contactor, wires or bus-
bars is visible, the safety of the contactor
is no longer guaranteed.
X
Immediately submit any damaged
contactors or components for
maintenance.
