Instruction Manual

Troubleshooting
Problem Cause Corrective Action
Excessive Noise
Wheel Rubbing Inlet
Adjust wheel and/or inlet cone. Tighten wheel hub or bearing
collars on shaft.
V-Belt Drive
Tighten sheaves on motor/fan shaft. Adjust belt tension. Align
sheaves properly (see page 9). 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 in-
place if necessary.
Volume Too Low
Fan Check wheel for correct rotation. Increase fan speed.
Duct System See page 4.
Volume Too High
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. Clean filters/
coils. Change fan speed.
Excessive Power
Consumption High
Horsepower
Fan Check rotation of wheel.
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.
Bearings Overheated
Lubrication Check for excessive or insufficient grease in the bearing.
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. Adjustable pitch
pulleys with motors over 15 hp motors are especially prone to
unbalance. Check wheel balance, rebalance if necessary.
WARNING
Before taking any corrective action, make certain unit
is not capable of operation during repairs.
AVERTISSEMENT
Avant d’entreprendre toute action corrective, s’assurer
que l’appareil ne pourra pas fonctionner durant les
réparations.
Mixed Flow 11