McQuay Skyline IM 777-1, Installation And Maintenance Manual

Page: 5 / 36

McQuay IM 777-1 3
Installation Guidelines
Curb Mounting and Unit Leveling
Do not place a Skyline unit over an open curb unless it is
equipped with a curb-ready base. Installation instructions for
mounting units on a roof curb are provided in IM 770. For a
copy, contact your local McQuay representative or visit
www.mcquay.com. Make provisions under the unit to divert
any moisture from entering the building below.
For units without roof curb mounting, place the equipment
on a flat and level surface. Where surface irregularities
exist, shim the base of the unit at one or more points along
the length of the rails to prevent distortion or sagging.
Uneven or distorted sections cause misfit or binding of the
doors and panels and improper draining of drain pans. See
Figure 4
.
Figure 4: Leveling the unit
Assembling Sections
If the unit is shipped in more than one shipping section, rig
each section into position separately. Shipping sections are
provided with a connection splice joint attached on the leaving
air side of the shipping section that seals against the frame
channel on the entering-air side of the adjoining section. The
splice joint is insulated and provides an air-tight seal between
two sections once they are assembled together. Align the splice
joint to seat into the mating gasket to provide an air seal. If the
splice joint was bent during shipping or rigging, restore it to its
original position. See Figure 7
.
To assemble shipping sections:
1
Caulk all assembly joints of the unit—Before joining the
sections, apply at least 1/4 inch diameter bead of sealant to
the mating faces of the cabinet. Use the splice joint as a
guide for applying the sealant. See Figure 5
.
Figure 5: Apply sealant to mating faces
2
Pull sections together to fasten. Use straps and a ratchet to
help pull the sections together securely. Apply sealant to
any gaps that may admit moisture.
3
Fasten base rails together first using the 3/8"-16 × 5" bolts
located in the splice kit provided with the unit. See
Figure 7.
a
To fasten two shipping sections together, 4 bolts are
needed (2 on each side of the unit). The bolts are run
from one base rail into the other and fastened with a nut.
Complete each section bottom and top before attaching
additional sections.
b
If desired, shipping sections for non curb-ready units
can be fastened together internally. To fasten internally,
run field-provided #10 sheet metal screws or drill
screws (4" long, maximum) through the interior frame
channel of one unit into the splice joint of the
neighboring section.
c
Handle units with curb-ready bases and vestibules so the
lifting bracket can be removed after the unit is placed on
the curbing.
– Remove the lifting bracket that projects inward over
the curbing. Save the self tapping screws.
– When the adjacent section is placed in position, use
self tapping screw to secure the bases together.
S h i m t o p r e v e n t
d i s t o r t i o n i f w i d t h
i s o v e r 1 0 8 "
S h i m s e c t i o n s u n t i l
t h e y a r e s t r a i g h t
a n d l e v e l
1 / 4 " d i a m e t e r
b e a d c e n t e r e d
i n f a c e o f
c l e a r a n c e
U s e S p l i c e
J o i n t a s a
g u i d e