SPX Cooling Technologies Marley MH 05-116E Manual De Usuario

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Motor will not start

Power not available at motor terminals

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

Wrong connections

Check motor and control connections against wiring diagrams.

Low voltage

Check nameplate voltage against power supply. Check voltage at 
motor terminals.

Open circuit in motor winding

Check stator windings for open circuits.

Motor or fan drive stuck

Disconnect motor from load and check motor and fan drive for cause 
of problem.

Rotor defective

Look for broken bars or rings.

Unusual motor noise

Motor running single-phase

Check motor and attempt to start it. Motor will not start if single-
phased. Check wiring, controls and motor.

Motor leads connected incorrectly

Check motor connections against wiring diagram on motor.

Bad bearings

Check lubrication. Replace bad bearings.

Electrical unbalance

Check voltages and currents of all three lines. Correct if required.

Air gap not uniform

Check and correct bracket fits or bearing.

Rotor unbalance

Rebalance

Cooling fan hitting end belt guard

Reinstall or replace fan.

Motor runs hot

Wrong voltage or unbalanced voltage

Check voltage and current of all three lines against nameplate values.

Overload

Check fan blade pitch. See Fan User Manual. Check for drag in fan 
drivetrain as from damaged bearings.

Wrong motor RPM

Check nameplate against power supply. Check RPM of motor and drive 
ratio.

Bearing overgreased

Remove bearing reliefs. Run motor up to speed to purge excessive 
grease.

Wrong lubricant in bearings

Change to proper lubricant. See motor manufacturer's instructions.

One phase open

Stop motor and attempt to start it. Motor will not stat if single-phased. 
Check wiring, controls and motor.

Poor ventilation

Clean motor and check ventilation openings. Allow ample ventilation 
around motor.

Winding fault

Check with ohmmeter.

Bent motor shaft

Straighten or replace shaft.

Insufficient grease

Remove plugs and regrease bearings.

Too frequent starting or speed changes

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.

Deterioration of grease or foreign material in grease

Flush bearings and relubricate.

Bearings damaged

Replace bearings.

Motor does not come up to 
speed

Voltage too low at motor terminals because of line 
drop

Check transformer and setting of taps. Use higher voltage on 
transformer terminals or reduce loads. Increase wire size or reduce 
inertia.

Broken rotor bars

Look for cracks near the rings. A new rotor may be required. Have 
motor service person check motor.

Wrong motor rotation

Wrong sequence of phases

Switch any two of the three motor leads.