Greenheck Housed Plenum Array , Plug and Plenum Fans (475405) - Manual (Page 14)

14 Housed Plenum Array, Plug and Plenum
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 V-Belt Drive 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 in place if
necessary.
Low CFM
Fan Check wheel for correct rotation. Increase fan speed.*
Duct system Check duct installations with poor inlet or discharge configurations.
High CFM Fan Decrease fan speed.
High Horsepower Fan Check rotation of wheel. Reduce fan speed.
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. Adjustable pitch pulleys
with motors over 15 hp are especially prone to unbalance. Check wheel
balance, rebalance if necessary.
* 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.
Troubleshooting