3-24. POWER CONTACTOR (cont)
CLEANING, INSPECTION, AND REPAIR (cont)
f. Armature (39).
(1) Inspect armature (39) for a rounded bearing
edge or uneven wear. If the armature
bearing edge is worn beyond 1/32 inch (0.
793 mm), replace the armature).
(2) Inspect the armature bracket (extension on
the end of the armature to which the
calibrating spring is attached).
(3) Inspect the pin over which the contact
pressure spring fits. Replace the pin if less
than 1/64 inch (0.396 mm) of pin remains
between the hole and the end of the pin.
(4) Inspect the armature shim. Replace shim if the portion between armature and magnet frame is pounded
more than halfway through or if the short, bent-up portion is worn more than two-thirds through.
Armature stop (29). Inspect the armature stop for grooving and uneven wear. If the armature stop is grooved
or worn more than 1/16 inch (1.58 mm) at the bearing edge of the armature, replace the armature stop.
Calibrating Spring (21). Inspect calibrating spring and replace spring if it is cracked, corroded, notched on the
end hook, or has lost its tension.
Contact pressure spring (32). Inspect pressure spring and replace spring if cracked, corroded, notched on end
hook, low on tension, annealed, or showing signs of electrical damage.
Stationary contact support (49).
(1) Inspect contact support for discoloration caused by overheating and for cracks. Replace contact if any of
the above conditions are found.
(2) Inspect the tapped hole for signs of burred, stripped, or damaged threads. Replace the contact if
of the hole will not restore the threads.
k. Base (56).
Inspect base (56) for soundness. Replace base if it appears to be oil soaked or cracked.
Paint base (56) with one or two coats of insulating varnish.