3-24. POWER CONTACTOR (cont)
Measure tip break as follows:
Make sure the contactor armature is against the stop when making the measurement; otherwise, the
reading will be false.
Measure the tip break (air gap) at the point of minimum spacing when tips are open.
Tip break shall be 14/32 to 19/32 inch (11.11 to 15.08 mm) for worn contactor and 15
/32 to 18/32 inch (11.9 to
14.29 mm) for new contactor.
If the tip break is not correct, check for the following conditions:
(1) Worn or bent contact tip
Bent armature stop
(3) Worn or bent contact lever
Adjust gap by bending the armature stop.
Measure tip alignment and adjust as follows:
The maximum allowable side-to-side misalignment of the contact tips is 3/32 inch (2.38 mm).
Check tip for misalignment. If necessary, loosen the screws holding the magnet frame and
support to the block and move the assembly until tips aline properly.
If tip misalignment cannot be corrected, check for the following conditions:
(1) Grooving or uneven wear of the armature stop
(2) Rounded knife edge or uneven wear of the armature pivot point
(3) Grooving or uneven wear of the armature guide
Measure tip pressure as follows:
Measure initial pressure as follows:
(1) Block the armature (not the tip lever) so the contacts nearly touch.
Measure the pull required to just move the contact-tip arm against the contact pressure spring.
Check for a pull of 3.6 to 6.5 lb (1.63 to 2.95 kg).