Lennox KGC092 - F-Check Belt Tension; MEASURE BELT TENSION; G-Field-Furnished Blower Drives

Page 14
F-Check Belt Tension
Overtensioning belts shortens belt and bearing life.
Check belt tension as follows:
1- Measure span length X. See figure 17.
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 new 2 and 3hp
belt, the deflection force should be 5.0-7.0 lbs.
(35-48kPa). For a new 5hp belt, the deflection
force should be 7-10lbs. (48-69kPa).
A force below these values indicates an
undertensioned belt. A force above these values
indicates an overtensioned belt.
MEASURE BELT TENSION
FIGURE 17
DEFLECTION 1/64” PER INCH OF SPAN
OR 1.5mm PER 100mm OF SPAN
FORCE
G-Field-Furnished Blower Drives
For field-furnished blower drives, use pages 15 through
17 to determine BHP and RPM required. Reference
table 4 for drive component manufacturer's numbers.