SPX Cooling Technologies MARLEY CLASS F400 - Manual (Page 14)

14
troubleshooting
Remedy
1. Check power at starter. Correct any bad connections between
the control apparatus and the motor.
2. Check starter contacts and control circuit. Reset overloads,
close contacts, reset tripped switches or replace failed control
switches.
3. 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 Geareducer for
cause of problem.
Look for broken bars or rings.
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 bade 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 Service Manual. Check for drag in
fan drive train as from damaged bearings.
Check nameplate against power supply. Check RPM of motor and
gear ratio.
Remove grease reliefs. Run motor up to speed to purge excessive
grease.
If not poor machining, replace worn bearing.
Change to proper lubricant. See motor manufacturer’s instruction.
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.
Flush bearings and relubricate.
Replace bearings.
See Fan Service Manual for blade pitching instructions.
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 man check motor.
Change any two of the three motor leads.
Cause
Power not available at motor terminals
Wrong connections
Low voltage
Open circuit in motor winding
Motor or fan drive stuck
Rotor defective
Motor running single-phase
Motor leads connected incorrectly
Ball bearings
Electrical unbalance
Air gap not uniform
Rotor unbalance
Cooling fan hitting guard
Wrong voltage or unbalanced voltage
Overload
Wrong motor RPM
Bearings overgreased
Rotor rubs stator bore
Wrong lubricant in bearings
One phase open
Poor ventilation
Winding fault
Bent motor shaft
Insufficient grease
Deterioration of or foreign material in grease
Bearings damaged
Incorrect fan blade pitch
Voltage too low at motor terminals because
of line drop
Broken rotor bars
Wrong sequence of phases
Trouble
Motor Will Not Start
Unusual Motor Noise
Motor Runs Hot
Motor Does Not Come Up
To Speed