COOK SQI - Manual (Page 2)

2
Wiring Installation (continued)
Leave enough slack in the wiring to allow for motor move-
ment when adjusting belt tension. Some fractional motors
have to be removed in order to make the connection with
the terminal box at the end of the motor. To remove motor,
remove bolts securing motor base to power assembly. Do
not remove motor mounting bolts.
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.
a. Loosen motor plate adjustment nuts on stud 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. 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 firmly press-
ing the belt. Refer to Figure1.
c. Lock the motor plate adjustment nuts in place.
d. Ensure pulleys are properly aligned. Refer to Figure 2.
Pulley Alignment
Pulley alignment is adjusted by loosening the motor pulley
setscrew and by moving the motor pulley on the motor
shaft.
Figure 2 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. Figure 3 illustrates using a carpenter’s square to
adjust the position of the motor pulley until the belt is paral-
lel to the longer leg of the square.
1 foot
1/4 inch
Figure 1
Final Installation Steps
a. Ensure that all accessories are
installed.
b. Ensure that the blower is secured to
ductwork.
c. Inspect wheel-to-inlet clearance.
Ensure wheel does not rub against the
inlet.
d. Test the fan to ensure the rotation of
the wheel is the same as indicated by
the rotation label.
e. Inspect for correct amperage with
an ammeter and correct voltage with a voltmeter.
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.
Operation
Pre-Start Checks
a. Lock out all the primary and secondary power sources.
b. Inspect and tighten fasteners and setscrews, particu-
larly fan mounting and bearing fasteners. Refer to Torque
chart.
c. Inspect belt tension and pulley alignment.
d. Inspect motor wiring.
e. Ensure fan and ductwork are clean and free of debris.
f. Close and secure all access doors.
g. 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 squealing).
• Improper motor amperage or voltage.
NOTICE! If a problem is discovered, immediately shut
the fan off. Lock out all electrical power and check for
the cause of the trouble. See Troubleshooting.
Inspection
Inspection of the fan should be conducted at the first 30
minute, 8 hour and 24 hour intervals of satisfactory opera-
tion. During the inspections, stop the fan and inspect as per
the chart below.
Figure 2
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
Figure 3
Motor Plate Adjustment
Motor Plate
Motor Plate
Adjustment Nut