ELECTRICAL COMPONENTS REPAIR INSTRUCTIONS
Section I. GENERATOR ASSEMBLY
(c) Check drive end head for cracks or
6 - 1 . General
warping. Inspect shaft end of armature for
The generator assembly has an armature
damage and wear.
mounted on bearings at both ends. The arma-
(d) Examine pulley for broken flanges
ture rotates between pole shoes over which are
and worn shaft hole. Inspect brushes for wear
wound field coils. The voltage and current
or damage.
developed in the armature windings is supplied
(3) Repair.
through brushes riding on a commutator to
(a) Check commutator with a dial in-
the generator terminals and then to the bat-
dicator for out-of-round. If total out-of-round
teries and other electrical accessories in the
exceeds 0.001 inch, turn down commutator on
circuit.
lathe.
(b) Replace armature or coils if tests
6-2. Generator and Components
indicate shorts.
a. Removal and Disassembly.
(c) Replace all parts indicating cracks,
wear, or damage.
described in paragraph 3-55.
(d) Replace brush springs that are
(2) Disassembly. Disassemble as shown
worn or fatigued. Replace brushes.
in figure 6-1.
(e) Undercut mica insulation between
the commutator bars to a depth of 1/32 of an
b. Cleaning, Inspection, Repair and Testing.
inch. When undercutting mica, the cut should
(1) Cleaning.
be square and free of burrs.
(a) Use a cloth dampened with an ap-
(4) Testing.
proved solvent to wipe all dust, oil, and other
foreign material from the brush plates, end
(a) Use a conventional test light and
frames, armature and field assemblies.
check field coils for open circuits and shorts to
(b) Use filtered compressed air to blow
ground or between coils.
dust and dirt from the crevices of the armature
(b) Check armature assembly for open
and field windings.
coils and shorts to ground, or between coils
(c) Secure armature in a lathe. With
by using a test light.
armature spinning, hold a sheet of No. 000
(c) Check brushholders for shorts to
sandpaper against the commutator until the
ground with a test light.
copper is bright and smooth.
c. Armature End Play Test.
(2) Inspection.
(1) Aline end of armature shaft with
(a) Examine field coils for worn,
plunger of dial indicator. Pull shaft to outer
burned insulation. Be certain connections
limit and set dial indicator.
between field coils are secure, Repair connec-
tions if necessary.
(2) Push shaft in toward commutator
end of generator to its inner limit. Dial indica-
(b) Examine field frame assembly for
tor should read between 0.003 and 0.010 inch.
cracks and distortions. Check thread condi-
tions in tapped holes,
(3) If dial indicator reading is not within
