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13
Detailed Component
Maintenance
Procedures
Fan Drive System
Model Specific Fan Drive
System Descriptions
Inspection & Maintenance
•
Belt tension check:
–
Place a straight edge along the belt from sheave to sheave as shown in
Figure 3a
, or
use a tape measure as shown in
Figure 3b
to measure belt deflection.
–
Apply a moderate force by hand (approximately 40 lbs/178 N) evenly across the
width of the belt in the center of the span between the sheaves.
–
There is adequate belt tension if the belt deflects between 1/4” and 3/8” as shown
in
Figures 3a
and
3b
.
NOTE:
If belts are properly
tensioned, there should be no
“chirp” or “squeal” when the fan
motor is started.
Motor Adjusting Screws
Figure 4a.
External Motor
Figure 4b.
Internal Motor
Motor Adjusting Screw
•
Belt tension adjustment (if required):
–
Remove the locking wrench (wrench attached to casing near motor/door) by
loosening the plastic thumbscrew.
–
Using the supplied locking wrench, wrench, or impact gun, turn the motor
base adjusting screw (
Figures 4a
and
4b
) clockwise to tension the belt or
counterclockwise to relieve belt tension. During adjustment of the belt tension,
rotate the drives several times by hand to evenly distribute the tension throughout
the belt. Keep hands away from pinch points such as where belts engage sheaves.
–
When the belt is properly tensioned, align the adjustment bolt to facilitate
replacement of the locking wrench. Replace the locking wrench and tighten the
plastic thumbscrew to secure.
Figure 3a.
Belt Tension with a Straight Edge
Figure 3b.
Belt Tension with a Tape Measure
DANGER:
Rotating equipment
will cause severe personal injury
or death to persons who come in
contact. Do not perform any service,
maintenance or inspection on or
near the fans, motors, and drives,
or inside the unit without first
ensuring that the fan and pump
motors are disconnected, locked
out, and tagged out.
