Check Belt Tension; Field-Furnished Blower Drives - Lennox LGH180H Installation Instructions Manual

Blowers Equipped With Belt Tensioner
1- Loosen the bolt in the center of the tensioner. See
figure 17.
2- Place belt over all three pulleys.
3- Using a 15/16" wrench, turn the tensioner nut until
marks align as shown in figure 17.
4- Hold the tensioner with marks aligned and tighten the
bolt to 23 ft.lbs. using the 9/16" wrench.
E-Check Belt Tension
Overtensioning belts shortens belt and bearing life.
Check belt tension as follows:
1- Measure span length X. See figure 18.
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.
LGH/LCH156, 180, 210, 240, 300S
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
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
F-Field-Furnished Blower Drives
For field-furnished blower drives, use page 17 or 18 to
determine BHP and RPM required. Reference table 3 to
determine the manufacturer's model number.
Page 16
these values indicates
FORCE
FIGURE 18
and