Blower Assembly; Pulley Alignment - Lennox ZHA036 Installation Instructions Manual

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.
SIDE VIEW
MOTOR
ALLEN
SCREW
PULLEY
TO DECREASE CFM
TO INCREASE CFM
LOOSEN ALLEN SCREW &
TURN PULLEY CLOCKWISE

PULLEY ALIGNMENT

ALIGNED
MOTOR
PULLEY BELT
NOT ALIGNED
FIGURE 11
1- Loosen four bolts securing motor base to mounting
frame. See figure 10.
2- To increase belt tension -
Slide blower motor downward to tighten the belt. This
increases the distance between the blower motor and
the blower housing.
To loosen belt tension -
Slide blower motor upward to loosen the belt. This
decreases the distance between the blower motor
and the blower housing.
3- Tighten four bolts securing motor base to the
mounting frame.
D - Check Belt Tension
Overtensioning belts shortens belt and bearing life.
Check belt tension as follows:
1- Measure span length X. See figure 12.
ZH 036, 048, 060

BLOWER ASSEMBLY

LOOSEN FOUR BOLTS
AND SLIDE BLOWER
MOTOR DOWNWARD
TO TIGHTEN BELT
TURN PULLEY
COUNTERCLOCKWISE
BLOWER
PULLEY
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
undertensioned 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
E-Field-Furnished Blower Drives
For field-furnished blower drives, use pages 9-14 to
determine BHP and RPM required. Reference page 15
for additional air resistance and drive kit numbers. See
table 2 for drive component manufacturer's numbers.
Page 8
below these values
FORCE
FIGURE 12
indicates an