CLCH-SVX03C-EN
75
Startup
Tension the Fan Belt
NOTICE
Belt Tension!
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 67. Tension drive belt label
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 67
).
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.
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 68. Belt tensioner
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 68
). 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 69
). Adjust the belt tension to the correct
pounds force and tighten all set screws to the proper torque.
Figure 69. Belt tension measurement
Small O-Ring
Force Scale
Large O-Ring
Span Scale
Belt Span
Belt Span
64
Deflection =