7
Centrifugal Single-Width Blower
®
Routine Maintenance and
Operation
Once the unit has been put into operation, a routine
maintenance schedule should be set up to accomplish
the following:
1. Lubrication of bearings and motor.
2. Wheel, housing, bolts and set screws on the entire
fan should be checked for tightness.
3. Any dirt accumulation on the wheel or in the
housing should be removed to prevent unbalance
and possible damage.
4. Inspect fan impeller and housing looking for fatigue,
corrosion, or wear.
Fan Operation
All fans should be run every thirty (30) days, or at least
“bumped” every thirty days. It is preferred that each
fan is run as this causes all electrical and mechanical
components to get up to temperature, displacing any
formed condensation, redistributes load on bearings,
and redistributes grease in the bearings (motor and
shaft bearings).
CAUTION
When operating conditions of the fan are to be
changed (speed, pressure, temperature, etc.),
consult manufacturer to determine if the unit can
operate safely at the new condition.
CAUTION
When performing any service to the fan, disconnect
the electrical supply and secure fan impeller.
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.
For more information about measuring belt tension,
refer to Greenheck’s Product Application Guide,
FA/127-11, Measuring Belt Tension, found online at
www.greenheck.com in the library section.
Check belt tension two times during the
first 24 hours of operation and periodically
thereafter.
Belt Span
Deflection = Belt Span
64
