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www.DaikinApplied.com 35
IM 777-8 • Skyline Air Handler
Adjusting
1. Slack off belt tension if belts have been installed.
2. Loosen setscrews
D
.
3. Loosen but do not remove capscrews
E
.
4. Remove key
F
.
NOTE:
This key projects a small amount to provide a grip for
removing.
5. Adjust pitch diameter by opening or closing the movable
flanges by half or full turns.
NOTE:
Two-groove sheaves are supplied with both grooves
set at the same pitch diameter.
6. To provide the same pitch diameter for satisfactory
operation, move both movable flanges the same number
of turns. Do not open sheaves more than five turns for
A
belts or six turns for
B
belts.
7. Replace key
F
.
8. Tighten setscrews
D
and capscrews
E
.
9. If belts have been installed, readjust belt tension. If belts
have not been installed, install them and adjust belt
tension.
Do not force belts over grooves .
See
See Fan
Drive Belt Adjustment on page 37
.
10. Before starting the drive, ensure that all keys are in
place and all setscrews and all capscrews are tight.
Check and retighten all screws and retention belts after
approximately 24 hours of operation.
Figure 48: LVP Type Sheave Adjustment
MVP Variable Speed Sheaves
Mounting
1. Verify both driving and driven sheaves are in alignment
and the shafts are parallel. The centerline of the driving
sheave must be in line with the centerline of the driven
sheave. See
Figure 49
.
2. Verify that all setscrews are torqued to the values shown
in
Table 28
before starting drive. Check setscrew torque
and belt tension after 24 hours of service.
Adjusting
1. Adjust motor base forward to release belt tension.
Remove the belts for easier adjustment.
2. Loosen, but do not remove both of the locking setscrews
A in the outer locking ring by using a hex key or torque
wrench with a hex bit.
3. Adjust sheave to desired pitch diameter by turning the
outer locking ring. Use a spanner wrench or drift inserted
into the three holes that are located 120° apart on the ring.
4. Any pitch diameter can be obtained within the sheave
range. One complete turn of the outer locking ring
changes the pitch diameter 0.233".
5. Do not open sheaves more than the following:
a. Do not open
B
sheaves more than 4, 3/4 turns for
the
A
belts or 6 turns for the
B
belts.
b. Do not open
C
sheaves more than 9, 1/2 turns.
c. Do not open
5V
sheaves more than 6 turns.
d. Do not open
8V
sheaves more than 8 turns.
6. Tighten BOTH locking screws
A
in the outer locking ring
before operating the drive. Use a torque wrench and
tighten to the value shown in
Table 28
.
7. Replace belts and adjust the motor base to tension the
belts properly. See
See Fan Drive Belt Adjustment on
page 37
.
8. Do not loosen any screws other than the two locking
screws
A
in the outer locking ring when adjusting the
sheave pitch. Do not operate the drive until the locking
screws have been set to the torque specifications.
Section A-A
Section A-A
A
B
C
D
E
F
D
E
A
E
C
F
D
A
A
