Product manual

McQuay IM 782-4 43
Service and Maintenance
7 Insert key F.
8 Tighten setscrews D and capscrews E.
9 Put on belts and adjust belt tension. Do not force belts
over grooves. See “Fan Drive Belt Adjustment” on page
28.
10 Be sure that all keys are in place and all setscrews and all
capscrews are tight before starting the drive. Check and
retighten all screws and retension belts after
approximately 24 hours of service.
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. (This key projects out 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. (Two-groove sheaves are
supplied with both grooves set at the same pitch
diameter.) Move both movable flanges the same
number of turns to provide the same pitch diameter
for satisfactory operation. Do not open sheaves more
than five turns for
A belts or six turns for B belts.
6 Replace key F.
7 Tighten setscrews D and capscrews E.
8 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 “Fan Drive
Belt Adjustment” on page 28.
9 Verify that all keys are in place and all setscrews and all
capscrews are tight before starting the drive. Check and
retighten all screws and retension belts after
approximately 24 hours of operation.
Figure 40: LVP Type Sheave Adjustment
MVP Variable Speed Sheaves
Mounting:
1 Verify that 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 26.
2 Before starting drive, verify that all setscrews are
torqued to the values shown in Table 25. Check setscrew
torque and belt tension after 24 hours of service.
Adjusting:
1 Adjust motor base forward to release belt tension. For
easier adjustment, remove the belts.
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 amounts:
• Do not open
B sheaves more than 4 3/4 turns for the A
belts or 6 turns for the
B belts.
• Do not open
C sheaves more than 9 1/2 turns.
• Do not open
5V sheaves more than 6 turns.
• Do not open
8V sheaves more than 8 turns.
6 Before operating the drive, tighten BOTH locking
screws
A in the outer locking ring. Use a torque wrench
and tighten to the value shown in Table 25.
7 Replace belts and adjust the motor base to tension the
belts properly. See “Fan Drive Belt Adjustment” on page
28.
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 are 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