19
Troubleshooting
Remedy
Stop motor and attempt to start it. Motor will not start if single-
phased. Check wiring, controls and motor.
Check motor connections against wiring diagram on motor.
Check lubrication. Replace bad bearings.
Check voltage and currents of all three lines. Correct if required.
Rebalance.
Check voltage and current of all three lines against nameplate
values.
Check nameplate RPM of motor and sheave ratio against parts
list. Measure RPM.
Remove grease reliefs. Run motor up to speed to purge excessive
grease.
Change to proper lubricant. See motor manufacturer’s instructions.
Stop motor and attempt to start it. Motor will not start if single-
phased. Check wiring, controls and motor.
Clean motor and check ventilation openings. Allow ample ventila-
tion around motor.
Check with Ohmmeter.
Straighten or replace shaft.
Remove plugs and regrease bearings.
Limit cumulative starting time to a total of 0 seconds each hour.
Flush bearings and relubricate.
Replace bearings.
Tighten all bolts and cap screws on all mechanical equipment and
supports.
Replace bearings.
Replace shaft.
Make sure fan and motor are straight and properly aligned.
Check belt for proper tension.
Disconnect load. Remove sheave, tape key in keyway and
operate motor. If motor still vibrates, rebalance motor.
Trouble
Unusual motor noise
Motor runs hot
Unusual fan drive
vibration
Cause
Motor running single-phase
Motor leads connected incorrectly
Bad bearings
Electrical unbalance
Rotor unbalance
Motor overload, wrong voltage or
unbalanced voltage
Wrong fan RPM
Bearings overgreased
Wrong lubricant in bearings
One phase open
Poor ventilation
Winding fault
Bent motor shaft
Insufficient grease
Too frequent starting
Deterioration of or foreign material
in grease
Bearings damaged
Loose bolts and cap screws
Worn fan shaft bearings
Bent shaft
Misalignment
Loose or stretched belt
Unbalanced motor
Summary of Contents for Aquatower 490A
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