Unit installation

Maintenance
82 SCXF-SVX01K-EN
Fan Bearings
The opposite drive end bearing is a special bearing with
close tolerance fit of balls and races. Replace this bearing
with the same part number as the original bearing.
Fan Belt Tension
Note: Check fan belt tension at least twice during the first
days of new belt operation since there is a rapid
decrease in tension until belts are run-in.
Proper belt tension is necessary to endure maximum
bearing and drive component life and is based on fan
brake horsepower requirements. If frayed or worn, replace
belts in matched sets.
Measuring Belt Tension
Measure fan belt tension with a Browning, Gates, or
equivalent belt tension gauge. Determine deflection by
dividing the belt span distance (in inches) by 64. See
Figure 46, p. 83. Follow the procedure below to measure
belt tension.
1. Measure belt span between centers of sheaves and set
the large “O” ring of the tensioning gauge at 1/64 inch
for each inch of belt span.
2. Set the load “O” ring at zero.
3. Place the large end of the gauge at the center of the belt
span.
Press down until the large “O” ring is even with
the top of the belt line or the next belt as in Figure 46,
p. 83. Place a straight edge across the sheaves as a
reference point. See Figure 45, p. 82.
4. Remove the gauge. Note that the load “O” ring now
indicates
a number on the plunger scale.This number
represents pounds of force required to deflect the belt.
Figure 45. Fan shaft and motor sheave alignment
NOTICE:
Bearing Failure!
Do not mix greases with different bases within the
bearing. Mixing grease within the bearing could result
in premature bearing failure.
Table 46. Compatible fan bearing grease
Recommended Grease Recommended Operating Range
Exxon Unirex #2
–20°F to 205°F
Mobile 532
Mobile SHC #220
Texaco Premium
Fixed
Sheave
Table 47. Fan hub and sheave torques
Unit size Fan Dia. Set Screw Size Torque (ft-lbs)
SCWF 20
18” 5/16” 12
SCWF 22
SCWF 25
SCRF 20
SCWF 29
18” 5/16” 12
SCWF 32
SCRF 25
SCRF 30
SCWF 35
20” 5/16” 14
SCWF 38
SCRF 30
SCRF 35
SCWF 42
25” 3/8” 24
SCWF 46
SCWF 52
SCWF 58
SCRF 40
SCRF 50
SCWF 65
27” 3/8” 24
SCWF 72
SCWF 80
SCRF 60
SCWF 90
SCWF C0
SCWF C1