11 8 CLCH-SVX07C-EN
Troubleshooting
This section is intended to be used as a diagnostic aid only. For detailed repair procedures, contact
your local Trane service representative.
WARNING
Hazardous Service Procedures!
The maintenance and troubleshooting procedures recommended in this section of the 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. When
possible, 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 equipment cannot 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 33. Air handler troubleshooting recommendations
Symptom Probable Cause Recommended Action
Bearing is
excessively hot
First start after relubrication (Grease distribution) Allow machine to cool down and restart.
Over-lubrication Clean surface of grease and purge.
Over tensioned belts Adjust belt tension.
No lubricant Apply lubricant. Check bearings for damage.
Misaligned bearing Correct alignment. Check shaft level.
Motor fails to
start
Blown fuse or open circuit breaker Replace fuse or reset circuit breaker.
Overload trip Check and reset overload.
Improper wiring or connections Check wiring with diagram supplied on unit.
Improper current supply
Compare actual supply power with motor nameplate
recommendations. Contact power company for adjustments.
Mechanical failure Check that motor and drive rotate freely. Check bearing lubricant.
Motor stalls
Open phase Check line for an open phase.
Overloaded motor Reduce load or replace with larger motor.
Low line voltage Check across AC line. Correct voltage if possible.
Excessive
vibration
Poor alignment
Align bearing set screws (see Table 26 on page 108). Loosen and
retighten bearing set screws.
Shipping spacers not removed
Remove shipping spacers and/or bolts (see “Fan Isolation” on
page 61).
Over tensioned belts Adjust belt tension.
Misaligned drive Align drive.
Motor runs and
then dies down
Partial loss of line voltage
Check for loose connections. Determine adequacy of main power
supply.
Starter shorts when motor warms up Replace starter.
Motor does not
come up to speed
Low voltage at motor terminals Check across AC line and correct voltage loss if possible.
Line wiring to motor too small Replace with larger sized wiring.
Motor overheats
Overloaded motor Reduce load or replace with a larger motor.
Motor fan is clogged with dirt preventing proper
ventilation
Remove fan cover, clean fan and replace cover.
Excessive motor
noise
Motor mounting bolts loose Tighten motor mounting bolts.
Rigid coupling connections Replace with flexible connections.
Worn motor bearings Replace bearings and seals.
Fan rubbing on fan cover Remove interference in motor fan housing.
Rapid motor
bearing wear
Excessive overhung load due to overtensioned drive Check belt tension and overhung load.
Excessive overhung load due to a small diameter motor
sheave
Replace sheave with larger one.
Loose fan belt
Motor is poorly positioned Adjust belt tension.
Worn or damaged belt Replace belt or belt set. Check sheave alignment.
Worn sheaves Replace sheaves.