Troubleshooting - SPX MARLEY CP User Manual

troubleshooting

Trouble Cause
Power not available at motor terminals
Wrong connections
Motor will not start
Low voltage
Open circuit in motor winding
Motor or fan drive stuck
Rotor defective
Motor running single-phase
Motor leads connected incorrectly
Bad bearings
Unusual motor noise
Electrical unbalance
Air gap not uniform
Rotor unbalance
Cooling fan hitting end belt guard
Wrong voltage or unbalanced voltage
Overload
Wrong motor RPM
Bearing overgreased
Wrong lubricant in bearings
One phase open
Motor runs hot
Poor ventilation
Winding fault
Bent motor shaft
Insufficient grease
Too frequent starting or speed changes
Deterioration of grease or foreign material in grease
Bearings damaged
Voltage too low at motor terminals because of line
drop
Motor does not come up
to speed
Broken rotor bars
Wrong motor rotation Wrong sequence of phases
14
Remedy
Check power at starter. Correct any bad connections between the control
apparatus and the motor.
Check starter contacts and control circuit. Reset overloads, close contacts,
reset tripped switches or replace failed control switches.
If power is not on all leads at starter, make sure overload and short circuit
devices are in proper condition
Check motor and control connections against wiring diagrams.
Check nameplate voltage against power supply. Check voltage at motor
terminals.
Check stator windings for open circuits.
Disconnect motor from load and check motor and fan drive for cause of
problem.
Look for broken bars or rings.
Check 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 voltages and currents of all three lines. Correct if required.
Check and correct bracket fits or bearing.
Rebalance
Reinstall or replace fan.
Check voltage and current of all three lines against nameplate values.
Check fan blade pitch. See "Fan User Manual. " Check for drag in fan
drivetrain and from damaged bearings.
Check nameplate against power supply. Check RPM of motor and drive
ratio.
Remove bearing 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 stat if single-phased.
Check wiring, controls and motor.
Clean motor and check ventilation openings. Allow ample ventilation
around motor.
Check with ohmmeter.
Straighten or replace shaft.
Remove plugs and regrease bearings.
Limit cumulative accelerations time to a total of 30 seconds/hour. Set on/
off or speed change set points farther apart. Consider installing a Marley
VFD drive for fine temperature control.
Flush bearings and relubricate.
Replace bearings.
Check transformer and setting of taps. Use higher voltage on transformer
terminals or reduce loads. Increase wire size or reduce inertia.
Look for cracks near the rings. A new rotor may be required. Have motor
service person check motor.
Switch any two of the three motor leads.