14
McQuay IM 777-2
Installation Guidelines
Internal Isolation Assembly Adjustment
On units with internally isolated fan and motor assemblies, the
assemblies are secured for shipment. with a tie-down at each
point of isolation.
Before Operating the Unit:
Remove the shipping brackets and tie-down bolts (see
Figure 22) and discard. The shipping brackets located on the
opposite drive side of the unit are difficult to access from the
drive side of the unit. Either remove them before the unit is
assembled, or remove the panel on the opposite drive side to
gain access.
The spring isolators under the four corners of the fan and
motor assembly are factory adjusted while the fan was not
running. See Table 1 below. With the unit operating at normal
cfm and static pressure, all the isolators should be at the same
height opening. If adjustments are required, loosen the 1/2"
cap screw on top of the isolator and turn the adjusting bolt to
lower or raise the fan and motor base. Retighten the cap screw
when adjustments are completed.
For models 040 through 090, the isolators should be at equal
height during fan operation (6"). Center the fan outlet in the
outlet panel opening. If adjustment is required, loosen the cap
screw on top of the isolator assembly. Turn the adjustment nut
below the fan frame to lower or raise the fan motor and frame
assembly. Retighten the cap screw on top of the isolator
assembly.
Figure 22: Removing Shipping Brackets
Table 1: Spring Mount Adjustments
Spring mount adjustment at rest
Fan discharge position
Top or bottom horz. (dim "H")
Unit sizes 003–035
1
3.75
2
4.25
3
4.25
4
3.75
Unit sizes 040–-090
1
6.00
2
6.50
3
6.50
4
6.00
M o t o r
F a n
P O S 1
P O S 2
P O S 3
P O S 4
A i r f l o w
F a n i s o l a t o r p o s i t i o n n u m b e r s
D i m " H "
S p r i n g h e i g h t
a d j u s t m e n t s c r e w
S p r i n g h e i g h t
a d j u s t m e n t s c r e w
S h i p p i n g h o l d
d o w n s c r e w
S h i p p i n g
b r a c k e t
D e t a i l A
S h i p p i n g h o l d d o w n
r e m o v e a n d d i s c a r d
( T y p i c a l 4 p l a c e s )
S e e d e t a i l " A "
S h i p p i n g b r a c k e t
r e m o v e a n d d i s c a r d
( T y p i c a l 4 p l a c e s )
Unit sizes 006 - 090
