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Check Belt Tension
Overtensioning belts shortens belt and bearing life. Check
belt tension as follows:
1− Measure span length X. See figure 10.
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
deflection force should be 5 lbs. (35kPa). A new belt
deflection 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
FIGURE 10
DEFLECTION 1/64" PER INCH OF SPAN
OR 1.5mm PER 100mm OF SPAN
FORCE
FIGURE 11
BLOWER ASSEMBLY
TO INCREASE BELT TENSION
1−Loosen four screws securing blower motor to
sliding base.
2−Turn adjusting screw to the left, or counter-
clockwise, to move the motor downward and
tighten the belt.
3−Tighten four screws.
TO INCREASE CFM
LOOSEN ALLEN SCREW &
TURN PULLEY CLOCKWISE
TO DECREASE CFM
TURN PULLEY
COUNTERCLOCKWISE
BLOWER
WHEEL
BLOWER
MOTOR
PULLEY
BLOWER
ASSEMBLY
SLIDING BASE
BELT TENSION
ADJUSTING
SCREW
LOOSEN (4) SCREWS TO
ADJUST BELT TENSION
REMOVE SCREWS TO
SLIDE BLOWER
ASSEMBLY OUT OF UNIT
PULLEY
MOTOR
ALLEN
SCREW
SIDE VIEW
