TM 11-6125-252-15
i. Unit Causes Radio Interference.
Possible cause
What to check
Remedy
Faulty capacitor. Defective coil
Test capacitors -------------------------
Replace faulty capacitor.
Sparking at commutator or slip-
Test coils for continuity and to ground
Repair or replace faulty part.
rings.
Inspect
commutator,
sliprings, and Clean commutator or sliprings; replace
brushes.
brushes.
hold the ac
a g o n a l nuts, and lockwashers that
5 - 6 . Repair
output receptacle (A010) in the filter box cover;
When the troubleshooting procedure locates a
remove the receptacle from the cover.
fault in the motor generator requiring disassem-
(13) Remove the dc input power wires from
bly and reassembly in order to make the repair,
the dc input terminal block (A082), noting the
follow the procedures below, Refer to figure 5-1
terminals from which they were removed; remove
for an exploded view of the motor generator and
the input cable and filter box cover from the
rotary converter.
a. Disassembly is accomplished by proceeding
(14) Remove the heavy black and white field
with the following steps:
coil wires from the terminal block, noting the
(1) Remove the ac brushes (A128).
terminals from which they were removed. Remove
the ac wires from the ground lug and choke coil
(2) Remove the dc brushes (A111).
L2 (A041). Remove the field coil wire from the
(3) Remove the inspection plate (A120)
terminal post connected to choke coil L1 (A036).
above the ac brushes.
(15) Remove the four machine screws and
(4) Remove the .01 f mica capacitor (A163)
lockwashers that secure the filter base assembly
to the rotary converter; carefully remove the
ac brush holder assemblies.
filter base assembly from the rotary converter
(5) Remove the four hexagonal nuts and
frame, noting where the respective field coil wires
split lockwashers from the thru bolts of the frame.
come through the rubber grommets on the base.
Remove the thru bolts.
NOTE
(6) Remove the ac endbell (A193) from the
field frame.
If the ac or dc brush holder assemblies
have to be removed for replacement,
(7) Carefully remove the armature (A195)
proceed with (16) and (17) below. If
while holding the baffle plate (A198). Armature
not, omit these steps.
shaft bearings (A196 and A197) will remain on
the shaft. After the armature is removed, the
(16) Remove the setscrews that secure the
baffle plate (A198) will fall free; remove.
ac brush holder assemblies in the ac endbell;
remove the ac brush assemblies.
NOTE
(17) Remove the four machine screws and
If the armature shaft bearings have to
lockwashers that secure the dc brush holder as-
be removed for replacement, proceed
semblies to the dc endbell; remove the two brush
with (8) below. If not, omit this Step.
holder assemblies (A146).
(8) Remove the armature shaft bearings
from the shaft, using a bearing puller.
b. Reassembly is accomplished by proceeding
with the following steps. Replace worn or dam-
(9) Remove the two dc leads to the dc brush
aged parts with new parts.
holders (fig. 4-2).
(1) Guide the field coil wires through their
(10) Remove the dc endbell (A161) from the
respective grommets in the filter base assembly
field frame.
and position the filter base assembly on the rotary
(11) Loosen the machine screws on the cable
converter; secure the filter base to the converter
clamp (A008) that holds the input power cable
with the four lockwashers and machine screws.
to the filter boX cover. Remove the four machine
screws that hold the filter box cover (A017) to
(2) Connect one ac wire to the ground lug
the filter box base (A095); lift the cover.
and the other to choke coil L2 (A041).
(12) Remove the two machine screws, hex-
(3) Connect the heavy black and white field
5-4
