80
T-Series Climate Changer Air Handler IOM •
CLCH-SVX06A-EN
Start-Up
Determine Fan Speed
Fan speed can be determined using a strobe-type tachometer, or revolution counter.
Check unit vibration if the fan speed is changed more than 5 percent from the original
designed speed, or if parts such as shafts, fan wheels, bearings, or other drive
components are replaced. Do not exceed the maximum fan speed.
Pay particular attention to any vibration, noise, or overheating of the motor and fan
bearings; however, note that bearings may run warm during break in.
Figure 61. Proper drive alignment
Sheave Alignment
Align the fan and motor sheaves using a straightedge. The
straightedge must be long enough to span the distance between
the outside edges of the sheaves. When the sheaves are aligned,
the straightedge will touch both sheaves at points
A
through
D
(see
Figure 61
) to confirm the shaft is parallel. For uneven width
sheaves, place a string in the center groove of both sheaves and
pull tight. Adjust the sheaves and tighten the sheave set screws to
the proper torque given in
Table 12
.
Multibelt Check
Tighten the belts slightly and rotate the drive several times.
On multiple belt drives, ensure the force of deflection is
approximately the same on each belt by pushing each belt in an
equal distance at a point halfway from each sheave (see
Figure 61
).
If this force is not the same for each belt, the motor and fan shaft
are not parallel. Realign as required. After realignment, tighten the
belts again to the standard belt tensioning specifications. If the
force is still not the same for all belts, the belts or sheaves are worn
and must be replaced.
Table 12. Fan and drive compound torque settings (inches)
Screw Size
Hex Key
Square Head
Hex Head
Torque (in.-lb.)
Torque (ft.-lb.)
1/4
1/8
3/8
7/16
66-90
5.5-7.5
5/16
5/32
1/2
1/2
126-164
10.5-13.7
3/8
3/16
9/16
9/16
228-300
19.0-25.0
7/15
7/32
5/8
5/8
348-450
29.0-37.5
1/2
1/4
3/4
3/4
504-650
42.0-54.2
5/8
5/16
15/16
15/16
1290-1390
107.0-116.0
#10
3/32
-
-
28-40
2.3-3.3