Service
Manual
9406
Relay repairs
The relay does not open or close
•
Check that the coil is energised. If so, check its
continuity. If the coil is open-circuited, replace it as
follows:
•
Remove the auxiliary top contact block as described
below under Replacement of Auxiliary Contact Block.
•
Undo the connector and remove it.
NB: The wires to the contacts do not need to be
removed.
•
Prise off the spring clips and carefully separate the two
halves of the main relay block. Be careful not to allow
the moving contacts to spring out.
•
Remove the connections to the coil and replace the coil.
•
Before re-assembly, check that the surfaces of the
magnetic core are clean and undamaged. Re-assemble
and reposition the connector.
Loud hum from the relay
•
Unscrew and disassemble the relay as described above.
•
Check that the shading windings are undamaged –
damaged shalding windings will result in considerable
hum. If the windings are damaged, replace the entire
relay.
•
Check that there are no foreign particles adhering to the
contact surfaces of the core. If necessary, carefully clean
the surfaces with fine emery cloth.
Relay is sticking
•
Remove and dissamble the relay as described above.
•
Check that the coil does not have any sharp edges or
flash that are/is preventing free movement of the moving
part of the core. Rub off any sharp edges or flash if
necessary.
•
Check that the moving contact carrier can move freely in
the relay casing, and that the moving contacts are
correctly located in their housings.
Relay is sticking
•
Replace the relay.
Replacement of the auxiliary contact block
•
Remove the auxiliary contact block as follows:
– Using one finger, press the rear edge of the
auxiliary contact block forwards and upwards
until the block disengages. (The rear edge is that
which is marked HN01/HN10: see diagram).
•
Fit the auxiliary contact block as follows:
– Position the auxiliary contact block on the body
of the relay so that the black tab of the auxiliary
contact block locates in the pole clips and the
red tab locates in the recess in the moving
contact block (see diagram).
– Press the auxiliary contact block backwards until
its rear edge drops down and clips into position.
•
Check that the auxiliary contact block is operating
properly, as follows:
– Press and release the red/green pin in the middle of
the auxiliary relay block, and check that the moving
contact carrier moves freely without binding.
0940
2
25. Relay
25
