25
Repair instructions
The contactor fails to make or break
• Check that the operating coil is energised. If this is
the case, take measurements at the coil to check
for a break. If a break has occurred, replace the
coil as follows.
• Undo the contactor and lift it out.
NOTE! The connection cables to the contacts do
not need to be removed.
• Price apart the spring brackets and carefully take
the contactor halves apart; be carefully so that the
movable contacts do not jump out.
• Loosen the connections to the coil.
• Replace the coil.
• Prior to reassembly, check that the contact
surfaces to the magnet core are clean and
undamaged.
• Reassamble and replace the contactor.
The contactor hums considerably
• Loosen and take the contactor apart as described
above.
• Check whether or not the screen windings are
intact. A damaged screen winding causes a loud
hum. If this is the case, replace the contactor.
• Check for foreign particles on the contact surfaces
of the magnet core. Clean carefully with a fine
emery cloth if necessary.
The contactor sticks
• Undo and take the contactor apart as described
above.
• Check that there are no burrs on the coil bobbin
which brake the motion of the movable contactor
halt. Where necessary, deburr.
• Check that the movable contact bridge can move
freely in the contactor housing and that the
movable contacts are correctly seated in their
holders.
Other contactor faults
• Replace the contactor.
2
25. Contactor
Service
Manual
9406