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2021-07-15 / V1.0
Contactors C320K/C320S – Installation and Maintenance Manual
Maintenance
8.3 Corrective maintenance
The contactors are largely maintenance-free. Therefore
there is no general requirement to replace parts during
its service life. Excepted from this are auxiliary switches.
Replacing the S870 auxiliary switches
Under normal operating conditions (there were no
short circuits in the control circuit), there is no general
need to replace the auxiliary switches.
However, in the event of a short circuit in the control
circuit, it is possible that the auxiliary switches may be
damaged and need to be replaced.
If auxiliary switches have to be replaced, always replace
all auxiliary switches of the contactor.
Only use identical types of auxiliary switches specified
for the contactor.
Safety
DANGER
Before starting work on the contactors,
make sure that
X
no voltage is present,
X
all safety regulations are fully ob-
served.
X
Be sure to observe chapter
“3. Hazards and safety precautions”
on page 6
.
Tools required
-
Continuity tester
Procedure
X
Pull off the receptacles of the control wires from
the auxiliary switches.
X
Carefully release the snap-fit hook (1) of the catch
mechanism.
-
Be careful not to damage the snap-fit hook!
X
Continue to hold the snap-fit hook (1) carefully
and turn the auxiliary switch (2) approx. 45° clock-
wise around the bearing pin (3).
X
Pull the auxiliary switch (2) off the bearing pin (3).
X
Place a new auxiliary switch (2) in approx. 45° posi-
tion (as shown in
Fig. 19
to
Fig. 22
) on the bearing
pin (3).
X
Carefully turn the auxiliary switch (2) counterclock-
wise around the bearing pin (3) until it slides into
the mounting and the snap-fit hook (1) engages.
X
Replace all other auxiliary switches in the same
way.
X
Plug the receptacles of the control wires back on
to the contacts of the auxiliary switches.
X
Check the correct connection of the control wires-
to the auxiliary switches.
X
Use a continuity tester to check the correct assign-
ment and correct function of the auxiliary switches.
X
Finally, subject the contactor to a complete check
as described in section
“7.3 Checks” on page 21
.
1
1
2
2
Fig. 19: C320K: Replacing the auxiliary switches - 1
2
2
3
3
Fig. 20: C320K: Replacing the auxiliary switches - 2
