Table of Contents
Advertisement
number of turns open. Any increase in fan speed
represents a substantial increase in horsepower
required from the motor. Always check motor load
amperage and compare to nameplate rating when
changing fan speed.
Routine Maintenance
Once the fan has been put into operation, a periodic
maintenance program should be set up to preserve
the reliability and performance of the fan. Items to
be included in this program are: Belts, Bearings,
Fasteners and Setscrews, Lubrication, and Removal
of Dust and Dirt.
WARNING
Always disconnect, lock and tag power source before
installing or servicing. Failure to disconnect power
source can result in fire, shock or serious injury.
Belts
Premature belt failures are frequently caused by
improper belt tension (either too tight or too loose) or
misaligned pulleys. The proper tension for operating
a V-belt is the lowest tension at which the belts will
not slip at peak load conditions. For initial tensioning,
the proper belt deflection halfway between pulley
centers is 1/64 inch (0.4 mm) for each inch of belt
span. For example, if the belt span is 64 inches
(1626 mm), the belt deflection should be one inch
(25 mm) using moderate thumb pressure at midpoint
of the drive. See figure shown below.
Slack
Side
Check belt tension two times during the first 24
hours of operation and periodically thereafter. To
adjust belt tension, simply loosen four fasteners
(two on each side of the motor plate) and slide the
motor plate away from the fan shaft until proper
belt tension is attained. On some fans, fasteners
attaching the motor to the motor plate must be
loosened in order to adjust the belt.
It is very important
that the drive pulleys
remain in proper
alignment after
adjustments are
made. Misalignment
of pulleys will result
in premature belt
wear noise, vibration
and power loss.
®
Bearings
(For belt drive fans only)
Bearings are the most critical moving part of the
fan and should be inspected at periodic intervals.
Locking collars and setscrews, in addition to
fasteners attaching the bearings to the bearing
plate, must be checked for tightness. In a clean
environment and temperatures above 32ºF (0ºC)
and below 200ºF (93ºC), fan shaft bearings with
grease fittings should be lubricated semi-annually
using a high-quality lithium based grease. If unusual
environmental conditions exist, temperatures below
32ºF (0ºC) and above 200ºF (93ºC), moisture or
contaminants, more frequent lubrication is required.
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 lubricated for
life.
Fasteners and Setscrews
Any fan vibration has a tendency to loosen
mechanical fasteners. A periodic inspection should
include checking all fasteners and setscrews for
tightness. Particular attention should be paid to
setscrews or taper-lock bushings attaching the
propeller to the motor shaft and the motor shaft to
the bearings. Loose bearing setscrews will lead to
premature failure of the fan shaft. In addition, check
all fasteners attaching the motor to the motor plate.
Lubrication
Refer to the paragraph on bearings for bearing
lubrication. Many fractional horsepower motors
installed on the smaller fans are lubricated for life
and require no further attention. Motors equipped
with oil holes should be oiled in accordance with the
manufacturer's instructions printed on the motor.
Use a high grade SAE 20 machine oil and use caution
not to over lubricate. Motors supplied with grease
fittings should be greased according to directions
printed on the motor.
Removal of Dust and Dirt
Dirt clogs cooling openings on the motor housing,
contaminates bearing lubricant and collects on
propeller blades causing severe imbalance if left
unchecked. The exterior surface of the motor, fan
panel and entire propeller should be thoroughly
cleaned periodically. Use caution and do not allow
water or solvents to enter the motor or bearings.
Motors or bearings must not be sprayed with steam
or water.
The filters also require periodic cleaning. The 2 inch
(51 mm) washable aluminum filters are accessed
through the bolted access panel.
Sidewall Propeller Fans • Exhaust, Supply and Filtered Supply
5
Advertisement
Table of Contents
