Troubleshooting - Trane UCCA Installation, Operation And Maintenance Manual

Troubleshooting

This section is intended to be used as a diagnostic aid only.
For detailed repair procedures, contact your local Trane
service representative.
Hazardous Service Procedures!
The maintenance and troubleshooting procedures recommended in this manual could result in exposure to electrical,
mechanical or other potential safety hazards. Always refer to the safety warnings provided throughout this manual
concerning these procedures. Unless specified otherwise, disconnect all electrical power including remote disconnect
and discharge all energy storing devices such as capacitors before servicing. Follow proper lockout/tagout procedures
to ensure the power can not be inadvertently energized. When necessary to work with live electrical components,
have a qualified licensed electrician or other individual who has been trained in handling live electrical components
perform these tasks. Failure to follow all of the recommended safety warnings provided, could result in death or
serious injury.
Table 21. Air handler troubleshooting recommendations
Symptom Probable Cause
First start after relubrication (Grease distribution)
Over-lubrication
Bearing is
Over tensioned belts
excessively hot
No lubricant
Misaligned bearing
Blown fuse or open circuit breaker
Overload trip
Motor fails to Improper wiring or connections
start
Improper current supply
Mechanical failure
Open phase
Motor stalls Overloaded motor
Low line voltage
Poor alignment
Excessive
vibration Over tensioned belts
Misaligned drive
Partial loss of line voltage
Motor runs and
then dies down
Starter shorts when motor warms up
Motor does not Low voltage at motor terminals
come up to
Line wiring to motor too small
speed
Overloaded motor
Motor overheats
Motor fan is clogged with dirt preventing proper
ventilation
Motor mounting bolts loose
Rigid coupling connections
Excessive motor
noise
Worn motor bearings
Fan rubbing on fan cover
Excessive overhung load due to over tensioned drive
Rapid motor
Excessive overhung load due to a small diameter motor
bearing wear
sheave
Motor is poorly positioned
Loose fan belt Worn or damaged belt
Worn sheaves
Worn sheaves
Misaligned belt
Short belt life Grease or oil on belts
Belt slipping
Belts rubbing
62
WARNING
Recommended Action
Allow machine to cool down and restart.
Clean surface of grease and purge.
Adjust belt tension.
Apply lubricant. Check bearings for damage.
Correct alignment. Check shaft level.
Replace fuse or reset circuit breaker.
Check and reset overload.
Check wiring with diagram supplied on unit.
Compare actual supply power with motor nameplate recommendations.
Contact power company for adjustments.
Check that motor and drive rotate freely. Check bearing lubricant.
Check line for an open phase.
Reduce load or replace with larger motor.
Check across AC line. Correct voltage if possible.
Align bearing set screws (see
bearing set screws.
Adjust belt tension.
Align drive.
Check for loose connections. Determine adequacy of main power supply.
Replace starter.
Check across AC line and correct voltage loss if possible.
Replace with larger sized wiring.
Reduce load or replace with a larger motor.
Remove fan cover, clean fan and replace cover.
Tighten motor mounting bolts.
Replace with flexible connections.
Replace bearings and seals.
Remove interference in motor fan housing.
Check belt tension and overhung load.
Replace sheave with larger one.
Adjust belt tension.
Replace belt or belt set. Check sheave alignment.
Replace sheaves.
Replace sheaves.
Realign drive with MVP sheave set at mean pitch diameter.
Check for leaky bearings. Clean belts and sheaves.
Improper belt tension. Adjust tension.
Remove obstruction or realign drive for clearance.
Table 16, page 53). Loosen and retighten
CLCH-SVX009A-EN