10
A-B
0.5” (13)
B-C
1.0” (25)
A-C
1.0” (25)
MAXIMUM ALLOWABLE
DIFFERENCE IN. (MM)
Fig. 7 - Unit Leveling Tolerances
Step 5 — Field Fabricate Ductwork
Cabinet return-air static pressure (a negative condition)
shall not exceed 0.35 inch wg (87 Pa) with economizer or
0.45 inch wg (112 Pa) without economizer.
For vertical ducted applications, secure all ducts to roof
curb and building structure.
Do not connect ductwork to unit.
Fabrica te supply ductwork so that the cross- sectional
dimensions are equal to or greater than t he unit supply
duct opening dimensions for the first 18 inches (458 mm)
of duct length from the unit basepan.
Insulate and weatherproof all external ductwork, joints,
and roof openings with counter flashing and mastic in
accordance with applicable codes.
Ducts passing through unconditioned spaces must be
insulated and covered with a vapor barrier.
If a plenum return is used on a vertical unit, the return
should be duc ted through the roof deck to comply wit h
applicable fire codes.
PROPERTY DAMAGE HAZARD
Failure to follow this caution may result in damage
to roofing materials.
Membrane roofs can be cut by sharp sheet metal
edges. Be careful when placing any sheet metal parts
on this type of roof.
CAUTION
!
For Optio n al Electric Heaters —
All installations require a minimum clearance to
combustible surfaces of 1 inch (25 mm) from the duct for
the first 12 inch (305 mm) away from unit.
NOTE:A90
° elbow must be provided in the ductwork to
comply with UL (Underwriters Laboratories) code for use
with electric heat.
PERSONAL INJURY HAZARD
Failure to follow this warning could cause personal
injury.
For vertical supply and return units, tools or parts
could drop into ductwork and cause an injury. Install
a90
° turn in the return ductwork be tween the unit
and the conditioned space. If a 90° elbow cannot be
installed, a grille of sufficient strength and density
should be i nstalled to prevent objects from falling
into the conditioned space. Due to electric heater, the
supply duct will require a 90
° elbow.
!
WARNING
Step 6 — Rig and Place Unit
Keep the unit upright and do not drop. Spreader bars are
not required if top crating is left on unit. Rollers may be
used to move unit across a roof. Le vel by using the unit
frame as a reference. See Table 3 and Fig. 8 for additional
information.
Lifting holes are provided in base rail s as shown in Fig. 8.
Refer to rigging instructions on unit.
Before setting unit onto curb, recheck gasketing on curb.
Rigging materials under unit (cardboard or wood) must be
removed PRIOR to placing the unit on t he roof curb.
When using the standard side drain connection, ensure the
red plug in the alternate botto m connectio n is tight. Do this
befor e setting the unit in place. The red drain pan plug can
be tightened with a 1/2 inch square socket drive extension.
For further details see “Step 8 - Install External Condensate
Tr ap and Line.”
UNIT DAMAGE HAZARD
Failure to follow this caution may result in
equipment damage.
All panels must be in place when rigging. Unit is not
designed for handling by forklift when packaging is
removed.
If using the top cra te as spreader bar once unit is set,
care f ully lower wooden crate off of the building roof
top to the ground. Ensure that no people or
obstructions are in the way bef ore lowering the crate.
CAUTION
!
40QQ
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