MK Diamond Baldor Motor - Manual (Page 27)

Maintenance & Troubleshooting 3-5 MN408
Table 3-6 Troubleshooting Chart
Symptom Possible Causes Possible Solutions
Motor will not start
Usually caused by line trouble, such as,
single phasing at the starter.
Check source of power. Check overloads, fuses,
controls, etc.
Excessive humming
High Voltage.
Eccentric air gap.
Check input line connections.
Have motor serviced at local Baldor service center.
Motor Over Heating
Overload. Compare actual amps
(measured) with nameplate rating.
Locate and remove source of excessive friction in motor
or load.
Reduce load or replace with motor of greater capacity.
Single Phasing. Check current at all phases (should be approximately
equal) to isolate and correct the problem.
Improper ventilation. Check external cooling fan to be sure air is moving
properly across cooling fins.
Excessive dirt build-up on motor. Clean motor.
Unbalanced voltage. Check voltage at all phases (should be approximately
equal) to isolate and correct the problem.
Rotor rubbing on stator. Check air gap clearance and bearings.
Tighten “Thru Bolts”.
Over voltage or under voltage. Check input voltage at each phase to motor.
Open stator winding. Check stator resistance at all three phases for balance.
Grounded winding. Perform dielectric test and repair as required.
Improper connections. Inspect all electrical connections for proper termination,
clearance, mechanical strength and electrical continuity.
Refer to motor lead connection diagram.
Bearing Over Heating
Misalignment. Check and align motor and driven equipment.
Excessive belt tension. Reduce belt tension to proper point for load.
Excessive end thrust. Reduce the end thrust from driven machine.
Excessive grease in bearing. Remove grease until cavity is approximately 3/4 filled.
Insufficient grease in bearing. Add grease until cavity is approximately 3/4 filled.
Dirt in bearing. Clean bearing cavity and bearing. Repack with correct
grease until cavity is approximately 3/4 filled.
Vibration
Misalignment. Check and align motor and driven equipment.
Rubbing between rotating parts and
stationary parts.
Isolate and eliminate cause of rubbing.
Rotor out of balance. Have rotor balance checked are repaired at your Baldor
Service Center.
Resonance. Tune system or contact your Baldor Service Center for
assistance.
Noise
Foreign material in air gap or ventilation
openings.
Remove rotor and foreign material. Reinstall rotor. Check
insulation integrity. Clean ventilation openings.
Growling or whining
Bad bearing. Replace bearing. Clean all grease from cavity and new
bearing. Repack with correct grease until cavity is
approximately 3/4 filled.