Utility Fans
13
Belt Drive Maintenance
V-belt drives must be checked on a regular basis
for wear, tension, alignment and dirt accumulation.
Premature or frequent belt failures can be caused by
improper belt tension (either too loose or too tight)
or misaligned sheaves. Abnormally high belt tension
or drive misalignment will cause excessive bearing
loads and may result in failure of the fan and/or motor
bearings. Conversely, loose belts will cause squealing
on start-up, excessive belt flutter, slippage and
overheated sheaves. Either excessively loose or tight
belts may cause fan vibration.
When replacing V-belts on multiple groove drives,
all belts should be changed to provide uniform
drive loading. Use a set of matched belts whenever
possible. Do not pry belts on or off the sheave.
Loosen belt tension until belts can be removed by
simply lifting the belts off the sheaves. After replacing
belts, ensure that slack in each belt is on the same
side of the drive. Belt dressing should never be used.
Do not install new belts on worn sheaves. If the
sheaves have grooves worn in them, they must be
replaced before new belts are installed.
The proper tension for operating a V-belt drive is
the lowest tension at which the belts will not slip at
peak load conditions. Belts are adjusted by raising or
lowering the motor
pivot plate. For
initial tensioning,
the proper
belt deflection
halfway between
sheave centers is
1/64-inch for each
inch of belt span.
Check belt tension two times during the
first 24 hours of operation and periodically
thereafter.
Belt Span
Deflection =
Belt Span
64
Wheel and Fastener Maintenance
Wheels require very little attention when exhausting
clean air, however, air heavily laden with grease or
dirt will tend to accumulate on the wheel causing
unbalance. Wheels exhausting dirty or grease-laden
air require frequent cleaning to assure smooth and
safe operation.
All fasteners, including set screws in the bearing
collars, should be checked for tightness each time
maintenance checks are performed.
A proper maintenance program will help preserve the
performance and reliability designed into the fan.
XUEF-100 Belt Adjustment
Belts on the XUEF-100 are adjusted from the exterior
of the fan. The end cover must be removed so that
the belt(s) can be inspected and checked for proper
tension.
1. Loosen, but DO NOT remove the four corner bolts
on the adjustment plate.
2. Loosen, then adjust L-bolts on adjustment plate to
tighten or loosen belt(s) as needed.
3. Tighten L-adjustment bolts and the four corner
bolts to lock motor in place after proper tension is
reached.
NOTE
Loosen the corner bolts as minimal as possible
to allow the plate to move, but so the plate has
minimal movement when bolts are re-tightened.
L-Adjustment
Bolts
Corner
Bolts
