Rockwell Automation 1329R Std. Industrial AC Induction Motors - Manual (Page 14)

14 Standard Industrial AC Induction Motors
Maintenance and Repair The fundamental principle of electrical maintenance is keep the
apparatus clean and dry. This requires periodic inspection of the
motor, the frequency depending upon the type of motor and the
service.
The following should be checked at regular intervals:
• Windings should be dry and free of dust, grease, oil and dirt.
Windings may be cleaned by suction cleaners or by wiping.
Nozzles on suction type cleaners should be nonmetallic. Gummy
deposits of dirt and grease may be removed by using a
commercially available low volatile solvent.
• Terminal connections, assembly screws, bolts and nuts should be
tight. They may loosen if motor is not securely mounted and tend
to vibrate.
• Insulation resistance of motors in service should be checked
periodically at approximately the same temperature and humidity
conditions to determine possible deterioration of the insulation.
When such measurements at regular intervals indicate a wide
variation, the cause should be determined. Motor should be
reconditioned if the motor has been subjected to excessive
moisture by re-winding or re-insulating if necessary. Enclosed
motors require very little attention. Ensure that the external air
chamber of fan-cooled motors does not become clogged with
foreign material which will restrict passage of air.
Disassembly
If it becomes necessary to disassemble the motor, care should be
taken not to damage the stator windings as the insulation may be
injured by improper or rough handling. Precautions to keep bearings
clean should also be exercised. Before removing either end shield:
1. Disconnect motor from power source. Label the leads to assure
proper reconnection.
2. Remove motor from mounting base. Remove fan cover and fan if
present.
3. Mark end brackets relative to position on frame so they can be
easily replaced.
!
ATTENTION: To ensure that the driven equipment is not
unexpectedly started, remove all power before proceeding.
Failure to observe this precaution could result in personal
injury or death.