GE GEH-5304A - Manual (Page 24)

GEH-5304A
24
Do not use liquid solvents of any kind. Solvents will not remove carbon dust
accumulations, but will spread and wash them into critical areas.
Figure 2
Brush Assembly
F. Commutator
Keep the commutator clean. Ordinarily, the commutator will require only occasional wiping with a piece of
canvas or other nonlinting cloth. Do not use lubricant or solvent on the commutator. Check the commu-
tator for roughness while running by feeling the brushes with a fibre stick, avoiding contact with live electri-
cal or moving mechanical parts. Chattering brushes give advance warning of deterioration of the commuta-
tor surface. (Refer to the Commutator Check Chart (GEA-7053) for commutator surface marking and causes
of poor commutator condition.) Commutator runout over .003” T.I.R. (Total Indicator Reading) and bar-to-
bar readings over .003” indicate need for repair. (Refer to Table 12.)
The presence of silicone in DC motors, particularly with totally enclosed con-
structions, will cause rapid brush wear. Sources of silicone include oils, RTV
compounds, hand creams, mold release agents, grease and some insulating
varnishes. These silicone substances must be avoided to ensure proper motor
performance.
Table 12
Commutator Diameters (In Inches)
Frame Start Min. Wear
CD2512AT 5.30 5.02 0.140
CD2513AT
CD2812AT
5.96 5.66 0.150
CD2813AT