11
Model BCSW-FRP
Problem
Cause
Corrective Action
Excessive Noise
Wheel rubbing (inlet)
Adjust wheel.
Tighten wheel hub or bearing collars on shaft.
V-belt drive
Tighten Sheaves on motor/fan shaft. Adjust belt tension. Align
sheaves properly (see V-Belt Drives section). Replace worn belts
or sheaves.
Bearings
Replace defective bearing(s). Lubricate bearings.
Tighten collars and fasteners.
Wheel unbalance
Clean all dirt off wheel. Check wheel balance, rebalance if
necessary.
Low CFM
Fan
Check wheel for correct rotation. Increase fan speed.*
Duct system
See page 3.
High CFM
Fan
Decrease fan speed.
Duct system
Resize ductwork. Access door, filters, grilles not installed.
Static Pressure
Wrong
Duct system
has more or less
restriction than
anticipated
Change obstructions in system. Use correction factor to adjust
for temperature/altitude. Resize ductwork. Change fan speed.*
High Horsepower
Fan
Check rotation of wheel. Reduce fan speed.
Duct system
Resize ductwork. Check proper operation of face and bypass
dampers. Check filters and access doors.
Fan Doesn’t Operate
Electrical supply
Check fuses/circuit breakers. Check for switches turned off or
disconnected. Check for correct supply voltage.
Drive
Check for broken belts. Tighten loose pulleys.
Motor
Assure motor is correct horsepower and not tripping overload
protector.
Overheated Shaft
Bearing
Lubrication
Check for excessive or insufficient grease in the bearings.
Mechanical
Replace damaged bearing. Relieve excessive belt tension. Align
bearings. Check for bent shaft.
Excessive
Vibration
Belts
Adjust tightness of belts. Replacement belts should be a matched
set.
System unbalance
Check alignment of shaft, motor and pulleys. Check wheel
balance, rebalance if necessary.
Coupling
misalignment
Check alignment between coupling, motor and fan shafts.
Any adjustments should be made per coupling manufacturer’s
instructions. Shim only under motor.
Troubleshooting
* Always check motor amps and compare to nameplate rating. Excessive fan speed may overload the motor and result in
motor failure. Do not exceed the maximum cataloged RPM of the fan.
NOTE: Always provide the unit model and serial numbers when requesting parts or service information.
