3-22. FIELD SHUNT CONTACTOR (cont)
f. Armature (42).
(1) Inspect armature for a
rounded bearing edge or
uneven wear. If the
armature bearing edge is
worn beyond 1/32 inch
(0.793 mm), replace the
(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)
the pin of 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 (45). 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 (32). Inspect calibrating spring and replace spring if it is cracked, corroded, notched on the
end hook, or has lost its tension.
Contact pressure spring (35). 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 tip support (19).
(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 tapping
of the hole will not restore the threads.