Installation manual

IM-487 Page 71
Bearings
Bearings are the most critical moving part of the fan and
should be inspected at periodic intervals. Locking collars and
set screws, in addition to fasteners attaching the bearings to
the bearing plate, must be checked for tightness. In a clean
environment and temperatures above 32°F/below 200°F,
lubricate fan shaft bearings with grease fittings semi-annu-
ally using a high quality lithium based grease. If unusual
environmental conditions exist, temperatures fall below
32°F/ or above 200°F, or if there is excessive moisture or
contaminants, then lubricate more often.
With the unit running, add grease very slowly with a manual
grease gun until a slight bead of grease forms at the seal. Be
careful not to unseat the seal by over lubricating or using
excessive pressure. Bearings without grease fittings are lubri-
cated for life.
Fasteners and Setscrews
Any fan vibration has a tendency to loosen mechanical fas-
teners. A periodic inspection should include checking all fas-
teners and set screws for tightness. It is important to tighten
setscrews attaching the propeller to the shaft and the
shaft to the bearings. Loose bearing set screws will lead to
premature failure of the fan shaft.
Lubrication
Refer to “Bearings” for bearing lubrication. Many fractional
horsepower motors installed on the smaller fans are lubricated
for life and require no further attention. Oil motors equipped
with oil holes in accordance with the manufacturer's instruc-
tions. Use a high grade SAE 20 machine oil and use caution
not to over lubricate.
Grease motors supplied with grease fittings according to
directions printed on the motor.
Removal of Dust/Dirt
Dirt clogs cooling openings on the motor housing, contami-
nates bearing lubricant and collects on propeller blades caus-
ing severe imbalance if left unchecked. Thoroughly clean the
exterior surface of the motor, fan panel and entire propeller
periodically. Use caution and do not allow water or solvents
to enter the motor or bearings. DO NOT spray motors or
bearings with steam or water.
Table 14: Propeller Exhaust Fan Troubleshooting
Figure 72. Propeller Exhaust Replacement Parts List
Problem Cause Corrective Action
Reduced Airflow
System resistance is too high.
Check backdraft dampers for proper operation. Remove
obstructions in ductwork. Clean dirty filters. Check for adequate
supply for air exhaust fans or exhaust air for supply fans.
Unit running backwards. See “Prestarting Checks” on page 69
Fan speed too low. Increase fan speed
Excessive dirt on propeller. Clean propeller
Excessive Noise
Bearings
Tighten bearing collars and setscrews. Lubricate bearings.
Replace defective bearings.
V-Belt drive
Tighten pulleys on motor shaft and fan shaft. Adjust belt tension.
Align pulleys. Replace worn belts or pulleys.
Excessive vibration
Clean dirt build-up from propeller. Check all setscrews and
fasteners for tightness. Check for worn bearing. Correct propeller
imbalance. Check for loose dampers, guards or ductwork.
Defective motor Replace motor.
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1 . F a n P a n e l
2 . P r o p e l l e r
3 . D r i v e F r a m e
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4 . M o t o r P l a t e
5 . M o t o r
6 . M o t o r P u l l e y
7 . S h a f t P u l l e y
8 . F a n S h a f t
9 . B e a r i n g s
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1 1 . B e a r i n g P l a t e