Lennox LCH036 Installation Instructions Manual page 14

TO INCREASE CFM TO DECREASE CFM
LOOSEN ALLEN SCREW &
TURN PULLEY CLOCKWISE COUNTERCLOCKWISE
SIDE VIEW
MOTOR
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.
E-Blower Belt Adjustment - Belt Drive
Maximum life and wear can be obtained from belts only
if proper pulley alignment and belt tension are
maintained. Tension new belts after a 24-48 hour
period of operation. This will allow belt to stretch and
seat grooves. Make sure blower and motor pulley are
aligned as shown in figure 21.
PULLEY ALIGNMENT
ALIGNED
MOTOR
BELT
PULLEY
NOT ALIGNED
FIGURE 21
1- Loosen four bolts securing motor base to mounting
frame. See figure 20.
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.
3- To loosen belt tension -
Slide blower motor upward to loosen the belt. This
decreases the distance between the blower motor
and the blower housing.
4- Tighten four bolts securing motor base to the
mounting frame.
BLOWER ASSEMBLY
TURN PULLEY
ALLEN
SCREW
PULLEY
BLOWER
PULLEY
LOOSEN FOUR BOLTS AND
SLIDE BLOWER MOTOR
DOWNWARD TO TIGHTEN BELT
FIGURE 20
F-Blower Belt Adjustment - Units Equipped With An
Optional Belt Tensioner
1- Remove blower belt.
2- Remove bracket from blower housing. See figure 23.
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 24.
G-Check Belt Tension
Overtensioning belts shortens belt and bearing life.
Check belt tension as follows:
1- Measure span length X. See figure 22.
MEASURE BELT TENSION
DEFLECTION 1/64" PER INCH OF SPAN
OR 1.5mm PER 100mm OF SPAN
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.
Page 14
LOOSEN ALLEN
SCREW TO
ADJUST CFM
FORCE
FIGURE 22
LGH/LCH036, 048, 060, 072