3-64. TRACTION MOTOR ASSEMBLY (cont)
CLEANING, INSPECTION, AND REPAIR (cont)
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, and pitting.
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 undercutting saw and regroove mica.
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.
Use dry, compressed air and remove loose mica and copper from commutator.
Do not paint commutator.
Paint surfaces of coil insulation with electrical insulating varnish.
Clean, inspect, and repair motor housing (42) 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 aid immediately.
· 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.
Use a wiping rag dampened with drycleaning solvent and remove dirt and foreign material from motor frame
and field assembly. Dry with compressed air.
Check that field coils, leads, and cable commutator are secure.