Table 15-4. Electric motors and controls.
Report any unusual conditions. Clean and lubricate those
motors assigned to the team for this purpose
Kcep area around motors free from obstructions.
(1) Unusual noises
(3) Accumulation of dust and moisture
(5) Difficulty in coming up to speed
Check oil level on sleeve bearing motors with oil gages.
Fill, if necessary. Add oil and check only when motor is
Check belts for suitable slack.. Adjust as necessary.
Check brushes in holders for fit and free play. Tighten
brush studs. Replace brushes if necessary.
Inspect commutator for high mica. glaze, roughness or
Check for vibration.
Check shunt, series, and commutating fields or tightness.
Check cable connections.
Check for bearing wear. Lubricate ball bearings.
Measure insulation resistanc e on motars over 10 hp.
Check winding insulation for cracks or other defects.
Make sure windings are dry.
Check air gap between rotor and stator on motors over 1
horsepower. Use long feeler gages for this purpose. A
record of yearly checks will give a picture of bearing wear.
A variation of 10 percent from one year to the next is
Cheek belts to insure that they are no tighter than necessary
to insure against slipping. Check chains for evidence of
Maintain proper alignment between motor and machine that
Check motor to see that end thrust is not excessive and
shaft has a reasonable axial float.
Lubricate motors. Flush and refill oil reservoirs. USe
lubricants recommended by equipment manufacture.
Frequency of lubrication depends on usage of motors.
Grease lubricated ball or roller bearing motors may require
lubrication only once a year if motor is operated lightly,
but as often as every 2 months if hard driven. Do not mix
greases of different type or specifications.