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2021-06-09 / V1.0
Contactors CPP series – Installation and Maintenance Manual
Maintenance
Component
Tests/checks
Measures
Contactor housing
Check for:
X
dirt
X
damage or wear
X
loose or missing fastening elements
In case of faults:
X
remove any dirt that may be present
X
if the contactor housing is damaged
or heavily worn replace the entire
contactor
X
tighten loose fastening elements im-
mediately replace missing fastening
elements
X
tighten a loose contactor immedi-
ately
Arc chamber
Check for:
X
dirt
X
damage or wear
X
traces of combustion residue (slight soot deposits
permitted)
X
correct and firm seating of the entire arc chamber
unit on the magnetic drive assembly
X
correctly engaged latching lever
In case of faults:
X
remove any dirt that may be present
X
if the housing is damaged or heavily
worn replace the complete arc cham-
ber
X
if there are holes in the housing walls,
replace the complete arc chamber
X
adjust the arc chamber in correct po-
sition and firm seating
X
make sure that the arc chamber is
latched securely
Main contacts
(both stationary
contacts and moving
contact bridge)
Prior to checking the main contacts, the arcing cham-
ber must first be removed, see section
“Removing the
arc chamber”
.
Thereafter, the main contacts are accessible and can
be checked for:
X
damage or wear
X
traces of combustion residue (slight soot deposits
permitted)
A certain level of experience is required to assess
the state of the contacts. Even after a few load
switching cycles, to a lay user the contacts appear
worn and the surroundings fouled. Replacement
of the contactor is only necessary after more than
70% of the contact material is burnt through.
In case of faults:
X
if more than 70% of the contact ma-
terial is burnt through, replace the
contactor as a whole unit.
Auxiliary switches
S870
Check for:
X
dirt
X
damage or wear on the housing
X
signs of short circuits
The auxiliary switches can be accessed from the
outside for a simple visual inspection.
Under normal working condition (there have
been no short circuits in the control circuit) the
life time of the auxiliary switches exceeds those of
the contactor.
In case of faults:
X
replace the auxiliary switches,
see section
“Replacing the S870 aux-
iliary switches”
