SPX Cooling Technologies F400 user manual Troubleshooting, Trouble Cause Remedy

Troubleshooting

Trouble	Cause	Remedy
Motor Will Not Start	Power not available at motor terminals	1. Check power at starter. Correct any bad connections be-
		tween the control apparatus and the motor.
		2. Check starter contacts and control circuit. Reset overloads,
		close contacts, reset tripped switches or replace failed con-
		trol switches.
		3. 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 Geareducer
		for cause of problem.
	Rotor defective	Look for broken bars or rings.
Unusual Motor Noise	Motor running single-phase	Stop 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.
	Ball bearings	Check lubrication. Replace bade 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 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 Service Manual. Check for drag
		in fan drive train as from damaged bearings.
	Wrong motor RPM	Check nameplate against power supply. Check RPM of motor
		and gear ratio.
	Bearings overgreased	Remove grease reliefs. Run motor up to speed to purge exces-
		sive grease.
	Rotor rubs stator bore	If not poor machining, replace worn bearing.
	Wrong lubricant in bearings	Change to proper lubricant. See motor manufacturer’s instruc-
		tion.
	One phase open	Stop motor and attempt to start it. Motor will not start if single-
		phased. Check wiring, controls and motor.
	Poor ventilation	Clean motor and check ventilation openings. Allow ample venti-
		lation around motor.
	Winding fault	Check with Ohmmeter
	Bent motor shaft	Straighten or replace shaft.
	Insufficient grease	Remove plugs and regrease bearings.
	Deterioration of or foreign material in	Flush bearings and relubricate.
	grease
	Bearings damaged	Replace bearings.
	Incorrect fan blade pitch	See Fan Service Manual for blade pitching instructions.
Motor Does Not Come Up	Voltage too low at motor terminals be-	Check transformer and setting of taps. Use higher voltage on
To Speed	cause of line drop	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 man check motor.

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