18
PNEG-1872
36" Direct Drive Box Fans
4. Troubleshooting Guide
Symptom
Probable Cause(s)
Corrective Action
Excessive noise.
Defective motor bearing.
Replace.
Defective pillow block bearing (if applicable).
Replace.
Damaged fan blade.
Replace blade. Recoat shaft with
anti-seize lubricant.
Motor not securely anchored.
Secure properly.
Housing fasteners loose, causing housing
to “oil can”.
Tighten fasteners.
Fan inoperative.
Open power supply circuit.
Replace fuse or reset circuit breaker. Check for
disconnected, cut or damaged power cord.
Electricity turned OFF.
Contact local utility supplier.
Defective motor.
Repair or replace.
Belt broken (if applicable).
Replace.
Insufficient airflow.
Intake or exhaust shutter jammed/clogged.
Repair/replace/clean as necessary.
Inlet/outlet guards clogged with dirt/debris.
Repair/replace/clean as necessary.
Excessive vibration.
Fan blade has excessive build-up of dirt.
Clean unit.
Fan blade is bent or otherwise damaged.
Replace blade. Recoat shaft with
anti-seize lubricant.
Motor/drive shaft (if applicable) is bent.
Replace.
Motor overheats and
nuisance trips.
Intake or exhaust shutter jammed/clogged.
Repair/replace/clean as necessary.
Inlet/outlet guards clogged with dirt/debris.
Repair/replace/clean as necessary.
Building operating static pressure too high.
Adjust air inlets to lower static pressure.
Motor has excessive build-up of dirt.
Clean unit.
Fan blade has excessive build-up of dirt.
Clean unit.
Power supply voltage is too low.
Check line voltage at motor, verify wiring is
of sufficient gauge for load and length of
conductor. Check with local utility supplier for
possible line problems.
