Pulley Alignment; Operation - COOK PLC Installation, Operation And Maintenance Manual

Wheel Rotation
Test the fan to ensure the rotation of the wheel is the
same as indicated by the arrow marked Rotation.
Airfoil
115 and 230 Single Phase Motors
Fan wheel rotation is set correctly at the factory. Chang-
ing the rotation of this type of motor should only be at-
tempted by a qualified electrician.
208, 230 and 460 3 Phase Motors
These motors are electrically reversible by switching
two of the supply leads. For this reason, the rotation of
the fan cannot be restricted to one direction at the factory.
See Wiring Diagrams for specific information on reversing
wheel direction.
NOTICE! Do not allow the fan to run in the wrong
direction. This will overheat the motor and cause
serious damage. For 3-phase motors, if the fan is
running in the wrong direction, check the control
switch. It is possible to interchange two leads at
this location so that the fan is operating in the
correct direction.
Belt and Pulley Installation
Belt tension is determined by the sound the belts make
when the fan is first started. The belts will produce a loud
squeal which dissipates after the fan is operating at full ca-
pacity. If belt tension is too tight or too loose, lost efficiency
and damage can occur.
Do not change the pulley pitch diameter to change
tension. This will result in a different fan speed.
1. Loosen motor plate adjustment bolts and move motor
plate in order that the belts can easily slip into grooves
on pulleys. Never pry, roll or force the belts over the
rim of the pulley.
2. Adjust the motor plate until proper tension is reached.
For proper tension, a deflection of approximately 1/4"
per foot of center distance should be obtained by firm-
ly pressing the belt. Refer to Figure 3.
3. Lock the motor plate adjustment nuts in place.
4. Ensure pulleys are properly aligned. Refer to Figure 4.
PLC IO&M
Backward
Inclined
Figure 3
Tolerance
OFFSET
Center Max.
Distance Gap
A
Up through 12" 1/16"
W
12" through 48" 1/8"
Over 48" 1/4"
X
Y
Z
B

Pulley Alignment

Pulley alignment is adjusted by
loosening the motor pulley setscrew
and by moving the motor pulley on
the motor shaft.
Figure 4 indicates where to mea-
sure the allowable gap for the drive
alignment tolerance. All contact
points (indicated by WXYZ) are to
have a gap less than the tolerance
shown in the table. When the pul-
leys are not the same width, the al-
lowable gap must be adjusted by half of the difference in
width. Figure 5 illustrates using a carpenter's square to ad-
just the position of the motor pulley until the belt is parallel
to the longer leg of the square.
Final Installation Steps
1. Inspect fasteners and setscrews, particularly fan
mounting and bearing fasteners then tighten accord-
ing to Recommended Torque for Setscrews/Bolts.
2. Inspect for correct voltage with a voltmeter.
3. Ensure all accessories are installed.

Operation

Pre-Start Checks
1. Lock out all the primary and secondary power sources.
2. Ensure fasteners and setscrews, particularly those
used for mounting the fan, are tightened.
3. Inspect belt tension and pulley alignment.
4. Inspect motor wiring.
5. Ensure belt touches only the pulley.
6. Ensure fan and ductwork are clean and free of debris.
7. Inspect wheel-to-inlet clearance. The correct wheel-
to-inlet clearance is critical to proper fan performance.
8. Close and secure all access doors.
9. Restore power to fan.
Start-Up
Turn on the fan. In variable speed units, set fan to its low-
est speed and inspect for the following:
• Direction of rotation
• Excessive vibration
• Unusual noise
• Bearing noise
• Improper belt alignment or tension (listen for squealing)
• Improper motor amperage or voltage
4
Figure 4
ANGULAR OFFSET/ANGULAR
CENTER
DISTANCE
(CD)
GAP
B51023-002
GAP