30 / 60
For example, if you are installing a 220J8, the minimum
allowance below center distance is 1/2 inch. If you are
working to maintain tension, the minimum allowance above
center distance for belt take-up is also 1/2 inch.
Shorter Center Distance for Poly-V® Belt Installation
Center Distance
Longer Center Distance for Poly-V® Belt Take-Up
13. Tension
Proper tension is essential for maximum belt life and efficiency.
Improper belt tension is the primary cause of premature belt
failure and increased costs. Under-tensioned belts lead to
slippage, overheating and noise, all of which lead to higher
maintenance costs and inefficient transmission of power. Also,
over-tensioning belts leads to premature wear, along with
bearing, shaft and pulley problems. The result is more frequent
replacement of drive components and costly downtime.
Common sense rules of Poly-V®
belt tensioning
The ideal tension is the lowest tension at which the belt will not
slip under peak load conditions.
Check the belt tension frequently during the first 24-48 hours
of run-in operation.
Do not over-tension belts. Doing so will shorten belt and
bearing life.
Keep belts free from foreign materials that may cause slippage.
Inspect the Poly-V® drive periodically. Re-tension the belts if
they are slipping.
Maintain sheave alignment with a strong straight-edge tool
while tensioning Poly-V® belts.
Table 15 Poly-V® Belt Recommended Installation and Take-Up Allowances
Recommended Installation and Take-Up Allowances (in.)
Standard
Effective Length
Minimum
Allowance
Below Standard
Center Distance
for Installation
of Belts
Minimum
Allowance
Above
Standard
Center Distance
for Maintaining
Tension,
All Cross
Selections
J
L M
Up to and including 20.0
0.4
0.3
Over 20.0 to and including 40.0 0.5
0.5
Over 40.0 to and including 60.0 0.6 0.9
0.7
Over 60.0 to and including 80.0 0.6 0.9
0.9
Over 80.0 to and including 100.0 0.7 1.0 1.5 1.1
Over 100.0 to and including 120.0 0.8 1.1 1.6 1.3
Over 120.0 to and including 160.0
1.2 1.7 1.7
Over 160.0 to and including 200.0
1.3 1.8 2.2
Over 200.0 to and including 240.0
1.4 1.9 2.6
Over 240.0 to and including 300.0
2.2 3.3
Over 300.0 to and including 360.0
2.3 3.9
Over 360.0 to and including 420.0
2.6 4.6
Over 420.0 to and including 480.0
2.9 5.2
Over 480.0 to and including 540.0
3.2 5.8
Over 540.0 to and including 600.0
3.6 6.5
30
Banded Belts
Installation Guide
‹
Under-Tensioned
Over-Tensioned
›
Belt Life Expectancy
100%
80%
60%
40%
20%
0%
Belt Tension
Optimal Belt Tension
Under-Tensioned
Over-Tensioned
Belt Life Expectancy vs. Tension
100% of Belt Life