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BLOWER ASSEMBLY
TO INCREASE BELT TENSION
1-Loosen four bolts securing motor base to mounting
frame.
2-Slide the motor downward to tighten the belt.
3-Tighten four bolts on motor base.
TO INCREASE CFM
LOOSEN ALLEN SCREW &
TURN PULLEY CLOCKWISE
TO DECREASE CFM
TURN PULLEY
COUNTERCLOCKWISE
PULLEY
MOTOR
SIDE VIEW
ALLEN
SCREW
LOOSEN FOUR BOLTS AND
SLIDE BLOWER MOTOR
DOWNWARD TO TIGHTEN BELT
LOOSEN ALLEN
SCREW TO
ADJUST CFM
FIGURE 11
PULLEY ALIGNMENT
BELT
BLOWER
PULLEY
MOTOR
PULLEY
NOT ALIGNED
ALIGNED
FIGURE 12
F-Blower Belt Adjustment - M Volt Units With 3 HP
Blowers Equipped With A Belt Tensioner
1- Remove blower belt.
2- Remove bracket from blower housing. See figure 14.
3- Remove the screw from the back side of the bracket.
4- Move the tensioner to the appropriate adjustment hole
and reinstall screw.
5- Replace bracket.
6- Replace blower belt. See figure 15.
G-Check Belt Tension - Units Not Equipped With A Belt
Tensioner
Overtensioning belts shortens belt and bearing life. Check
belt tension as follows:
1- Measure span length X. See figure 13.
2- Apply perpendicular force to center of span (X) with
enough pressure to deflect belt 1/64” for every inch of
span length or 1.5mm per 100mm of span length.
Example: Deflection distance of a 40” span would be
40/64” or 5/8”.
Example: Deflection distance of a 400mm span would
be 6mm.
3- Measure belt deflection force. For a used belt, the de
flection force should be 5 lbs. (35kPa). A new belt de
flection force should be 7 lbs. (48kPa).
A force below these values indicates an underten
sioned belt. A force above these values indicates an
overtensioned belt.
MEASURE BELT TENSION
DEFLECTION 1/64” PER INCH OF SPAN
OR 1.5mm PER 100mm OF SPAN
FORCE
FIGURE 13
Initiate blower demand at thermostat according to instruc
tions provided with thermostat. Unit will cycle on thermostat
demand. The following steps apply to applications using a
typical electro-mechanical thermostat.
H-Field-Furnished Blower Drives
For field-furnished blower drives, use belt drive blower ta
bles to determine BHP and RPM required. Reference the
drive kit specification table and manufacturer's drive num
ber table.
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