3-62. TRACTION MOTOR ASSEMBLY (cont)
CLEANING, INSPECTION, AND REPAIR (cont)
g. Use a dial indicator and check commutator for roughness or out-of-roundness. Commutator is out-of-round if
there is a 0.002 inch (0.05 mm) variance within a six bar span. Inspect surface for wear, burns, or pitting. If
these conditions exist, use fine grinding stones and resurface commutator.
When traction motor or under-locomotive equipment must be inspected while the engine is running,
remove excitation from the main generator and set airbrakes. Move reverser to center position and
remove from the controller. This will prevent accidental movement of the locomotive and possible injury
(4) Check that mica is undercut to a depth of 1/16 to 3/32 inch (1.6 to 2.4 mm). If mica depth is not within
these limits, use an undercutter and regroove mica.
(5) Clean slots between copper bars to remove burrs.
Compressed air used for cleaning purposes will not exceed 30 psi (207 kPa). Do not direct compressed
air against skin. Use goggles or full face shield to prevent injury to personnel.
(6) Use dry compressed air and remove loose mica and copper from commutator.
(7) Paint surfaces of coil insulation with red enamel insulating vanish. 33. Clean, inspect, and repair stator
frame assembly by the following:
Drycleaning solvent P-D-680 is toxic and flammable. Wear protective goggles and gloves and use only in
a well-ventilated area. Avoid contact with skin, eyes, and clothes and don't breathe vapors. Do not use
near open flame or excessive heat. The flash point is 100-138°F (38-59°C). If you become dizzy, get
fresh air immediately and get medical aid. If contact with eyes is made, wash your eyes and get medical
a. Use a cloth dampened with drycleaning solvent and remove dirt and foreign material from traction motor frame
and field assembly. Dry with compressed air.
b. Check that field coils, leads, and cable commutator are secure.