14
McQuay IM 777-4
Mechanical Installation
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 23
and
Figure 24
) 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
and
Table 2
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
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: Adjusting Large Spring Mount Assembly
Table 1: Motor Beside Fan Spring Mount Adjustments
Spring mount adjustment at rest
Fan discharge
position
Top or bottom
horz. H
Downblast
H
Upblast
H
Unit sizes 003 – 035
1
3.75
3.75
4.25
2
4.25
3.75
4.25
3
4.25
3.75
4.25
4
3.75
3.75
4.25
Unit sizes 040 – 090
1
6.00
6.75
6.75
2
6.50
6.75
6.75
3
6.50
6.75
6.75
4
6.00
6.75
6.75
Table 2: Motor Behind Fan Spring Mount Adjustments
Spring mount adjustment at rest
Fan discharge
position
Top or bottom
horz. H
Downblast
H
Upblast
H
Unit sizes 003 – 035
1
6.75
6.75
6.75
2
6.75
6.75
6.75
3
6.75
6.75
6.75
4
6.75
6.75
6.75
Unit sizes 040 – 090
1
6.75
6.75
6.75
2
6.75
6.75
6.75
3
6.75
6.75
6.75
4
6.75
6.75
6.75
Adjusting bolt
6"
