Maintenance; V-Belt Drives - Greenheck TCF Installation, Operation And Maintenance Manual

11. If the fan has inlet vanes, they should be partially
closed to reduce power requirements.
12. Fans with multi-speed motors should be checked
on low speed during initial start-up.
13. Ensure proper wheel location for radial gap,
overlap and alignment (see Radial Gap, Overlap
& Alignment section on page 3).
14. Grease may be forced out of the bearing seals
during initial start-up. This is a normal self-
purging feature of the bearing.
15. Check for unusual noise, vibration or overheating
of bearings. Refer to the Troubleshooting section
of this manual if a problem develops.
Vibration
Excessive vibration is the most frequent problem
experienced during initial start-up. Left unchecked,
excessive vibration can cause a multitude of
problems, including structural and/or component
failure.
The most common sources of vibration are:
Wheel unbalance
Drive pulley misalignment
Incorrect belt tension
Bearing misalignment
Mechanical looseness
Faulty belts
Drive component unbalance
Poor inlet/outlet conditions
Foundation stiffness
Many of these conditions can be discovered by careful
observation. Refer to the Troubleshooting section
of this manual for corrective actions. If observation
cannot locate the source of vibration, a qualified
technician using vibration analysis equipment should
be consulted. If the problem is wheel unbalance,
in-place balancing can be done providing there is
access to the fan wheel. Any correction weights
added to the wheel should be welded to either the
wheel back (single-plane balance) or to the wheel
back and wheel cone (two-plane balance).

Maintenance

WARNING
Disconnect and secure to the "Off" position all
electrical power to the fan prior to inspection
or servicing. Failure to comply with this safety
precaution could result in serious injury or death.
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. Variable inlet vanes should be checked for freedom
of operation and wear.
3. Wheel, housing, bolts and set screws on the entire
fan should be checked for tightness.
®
4. Any dirt accumulation on the wheel or in the
housing should be removed to prevent unbalance
and possible damage.
5. Isolation bases should be checked for freedom
of movement and the bolts for tightness. Springs
should be checked for breaks and fatigue. Rubber
isolators should be checked for deterioration.
6. Inspect fan impeller and housing looking for
fatigue, corrosion or wear.
WARNING
Changing the belts or drives can significantly
increase the amp draw of the motor. If changes
are made to the drives or belts, the amps must be
checked to assure no overamping.

V-Belt Drives

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. 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 half-way between sheave
centers is 1/64 of the belt span. For example, if the
belt span is 64 inches, the belt deflection should be
1 inch using moderate thumb pressure at mid-point
of the drive. Check belt tension two times during
the first 24 hours of operation and periodically
thereafter.
Belt Span
Models TCF and Model QEI/QEID Centrifugal
Deflection = Belt Span
64
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