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CLCH-SVX009A-EN
51
Tension the Fan Belt
Proper belt tension is required to ensure maximum
bearing and drive component life and is based on motor
horsepower requirement. A label located on the bearing
support on the drive side of the unit lists all drive parts, the
proper belt tension, and deflection for that tension for the
specific drive (
Figure 43
).
If the drive is changed from the original, proper belt
tension can be estimated using
Table 15
.
The correct operation tension for a V-belt drive is the
lowest tension at which the belts will not slip under the
peak load conditions. It may be necessary, however, to
increase the tension of some drives to reduce excessive
belt flopping or to reduce excessive startup squealing.
Check the fan belt tension at least three times during the
first days of operation because there is a rapid decrease in
tension until the belt settles in. To measure belt tension,
use a belt tensiometer (see
Figure 44
). Determine actual
deflection by depressing one belt with the belt
tensiometer and measuring the deflection relative to the
other belts or to belt line (see
Figure 45
). Adjust the belt
tension to the correct pounds force and tighten all bolts to
the proper torque. See
Table 18
.
NOTICE:
Belt Tension! (2 of 2)
Do not over-tension belts. Excessive belt tension will
reduce fan and motor bearing life, accelerate belt wear
and possibly cause shaft failure. Under tensioning belts
is the primary cause of premature belt failure. Belts
should not squeal at startup. Recheck belt tension after
8 hours, 24 hours, and 100 hours of operation and
monthly thereafter.
Figure 43.
Tension drive belt label
V-BELT DRIVE KIT
1627373
MODULE 0400
PURCHASE ORD. NUMBER B24597-061 H5D073B A
CUSTOMER’S KIT # H5D073B A-012-0400
MTR HP.= 10.0
FAN RPM = 1458 CD = 9.4 AT 3.00 TRN OPN
TENSION INFO - 3.86 LB., 0.14 IN.
DRIVE’S BELTS - B40
MOTOR SHEAVE - 2VP75X 1 3/8
MOTOR BUSHING - NONE REQUIRED
FAN SHEAVE - 2B5V80
FAN BUSHING - B 1 7/16
Figure 44.
Belt tensioner
Figure 45.
Belt tension measurement
Small O-Ring
Force Scale
Large O-Ring
Span Scale
Belt Span
Belt Span
64
Deflection =
