ENGINE DIVISION SERVICE MANUAL
ELECTRICAL
Fig. 11. Testing Armature for CG-6685 Short Circuits
Heavy Duty Drive Clutch Motor
1.
Disconnect field coil connector from solenoid motor
terminal and lead from solenoid ground terminal.
2.
Motors which have brush inspection plates, remove
the plates, then remove the brush lead screws which
disconnect the field leads from the brush holders.
3.
Separate the commutator end frame from the field
frame.
4.
Separate the nose housing and field frame from the
lever housing.
5.
Remove the armature and clutch assembly from
lever housing.
6.
Separate solenoid from lever housing by pulling
apart.
INSPECTION AND REPAIR
1.
Brushes and Brush Holders - Inspect the brushes for
wear. If they are worn down to one-half their original
length, when compared with a new brush, they
should be replaced. Clean brush holders and be
sure that the brushes will not bind in the holders.
The full length of the brush surface should ride on
the commutator with spring tension to provide a good
con-
tact. Inspect the brush leads and screws to be sure
they are tight and clean.
2.
Armature - Inspect the armature to be sure there are
no short circuits, open or grounds.
a.
Short circuits are located by turning the armature
in a growler while holding a steel strip on the
armature. The steel strip will vibrate on the area
of the short circuit, see Fig. 11.
b.
Opens are usually found where the conductors
are joined to the commutator. Loose or poor
connections will cause arcing and burning of the
commutator. If the bars are not burned too bad,
resolder the leads in the riser bars and turn the
commutator down in a lathe. Then under cut the
insulation between the commutator bars 1/32".
c.
Grounds in the armature can be found using a
test lamp and prods, see Fig. 12. If the lamp
lights when one prod is positioned on the
commutator and the other prod on the armature
core
or
shaft
the
armature
is
grounded.
CGES-230 - Page 12
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