4
d. Ensure pulleys are properly aligned. Refer to Figure 4.
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 measure 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 pulleys are not the
same width, the allowable gap must be
adjusted by half of the difference in width
(As shown in A & B of Figure 4).
Figure 5
illustrates using a carpenter’s square to
adjust the position of the motor pulley until
the belt is parallel to the longer leg of the
square.
Final Installation Steps
a. Inspect fasteners and setscrews,
particularly fan mounting and bearing fasteners, and
tighten according to the recommended torque shown
in the table
Recommended Torque for Setscrews/
Bolts
.
b. Inspect for correct voltage with voltmeter.
c. Ensure all accessories are installed.
Operation
Pre-Start Checks
a. Lock out all the primary and secondary power
sources.
b. Ensure fasteners and setscrews, particularly those
used for mounting the fan, are tightened.
c. Inspect belt tension and pulley alignment.
d. Inspect motor wiring.
e. Ensure belt touches only the pulleys.
f. Ensure fan and ductwork are clean and free of debris.
g. Inspect wheel-to-inlet clearance. The correct wheel-
to-inlet clearance is critical to proper fan performance.
h. Close and secure all access doors.
i. Restore power to the fan.
Start Up
Turn the fan on. In variable speed units, set the fan to its
lowest speed and inspect for the following:
• Direction of rotation.
• Excessive vibration.
• Unusual noise.
• Bearing noise.
• Improper belt alignment or tension (listen for squeal-
ing).
• Improper motor amperage or voltage.
Figure 4
Tolerance
Center
Distance
Maximum
Gap
Up thru 12”
1/16”
12” up through 48
1/8”
Over 48”
1/4”
OFFSET
ANGULAR
OFFSET/ANGULAR
A
W
X
Y
Z
B
CENTER
DISTANCE
(CD)
GAP
GAP
NOTICE! Follow the wiring diagram in the disconnect
switch and the wiring diagram provided with the motor.
Correctly label the circuit on the main power box and
always identify a closed switch to promote safety (i.e.,
red tape over a closed switch).
Wheel Rotation
Test the fan to ensure the rotation of the wheel is the
same as indicated by the arrow marked Rotation.
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
attempted 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 on page 3 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 seri-
ous 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. Belts will produce a loud
squeal which dissipates after the fan is operating at full
capacity. If the belt tension is too tight or too loose, lost effi-
ciency and possible damage can occur.
Do not change the pulley pitch diameter to change ten-
sion. This will result in a different fan speed than desired.
a. Loosen motor plate adjustment bolts and move motor
plate in order that the belts can easily slip into the
grooves on the pulleys. Never pry, roll, or force the
belts over the rim of the pulley.
b. Slide the motor plate back until proper tension is
reached. For proper tension a deflection of approxi-
mately 1/4” per foot of center distance should be
obtained by firmly pressing the belt. Refer to figure 3.
c. Lock the motor plate adjustment bolts in place.
Airfoil
Backward
Inclined
1 foot
1/4 inch
Figure 3
Figure 5