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9
Fig. 5 — Unit Leveling Tolerances
Step 5 — Field Fabricate Ductwork
Cabinet return-air static pressure (a negative condition) shall
not exceed 0.35 in. wg (87 Pa) with economizer or 0.45 in. wg
(112 Pa) without economizer.
For vertical ducted applications, secure all ducts to roof curb
and building structure.
Do not connect ductwork to unit.
Fabricate supply ductwork so that the cross sectional dimen-
sions are equal to or greater than the unit supply duct opening
dimensions for the first 18 in. (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 ducted through the roof deck to comply with applicable fire
codes.
UNITS WITH ACCESSORY ELECTRIC HEATERS
All installations require a minimum clearance to combustible
surfaces of 1 in. (25 mm) from duct for first 12 in. (305 mm)
away from unit.
Outlet grilles must not lie directly below unit discharge.
NOTE: A 90-degree elbow must be provided in the ductwork to
comply with UL (Underwriters Laboratories) code for use with
electric heat.
Step 6 — Rig and Place Unit
Keep unit upright and do not drop. Spreader bars are required.
Rollers may be used to move unit across a roof. Rigging mate-
rials under unit (cardboard or wood) must be removed PRIOR
to placing the unit on the roof curb. Level by using unit frame
as a reference. See Table 2 on page 6 and Fig. 6 for additional
information.
Lifting holes are provided in base rails as shown in Fig. 6. Re-
fer to rigging instructions on unit.
Before setting the unit onto the curb, recheck gasketing on
curb.
Position unit on roof curb so that the following clearances are
maintained:
1
/
4
in. (6.4 mm) clearance between the roof curb
and the base rail inside the front and rear, 0.0 in. clearance be-
tween the roof curb and the base rail inside on the duct end of
the unit. This will result in the distance between the roof curb
and the base rail inside on the condenser end of the unit being
approximately
1
/
4
in. (6.4 mm).
Although unit is weatherproof, guard against water from higher
level runoff and overhangs.
After unit is in position, remove the compressor access panel.
Holding the blocking between compressors with one hand, cut
the strapping. Carefully remove the blocking without damag-
ing tubing, wiring, or controls. Remove the strapping and re-
place the access panel.
After unit is in position, remove rigging skids and shipping
materials.
CAUTION
Failure to follow this caution may result in damage to roof-
ing materials.
Membrane roofs can be cut by sharp sheet metal edges. Be
careful when placing any sheet metal parts on such roof.
A
B
C
MAXIMUM ALLOWABLE
DIFFERENCE IN. (MM)
A-B
B-C
A-C
0.5 (13)
1.0 (25)
1.0 (25)
WARNING
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 a 90-degree
turn in the return ductwork between the unit and the condi-
tioned space. If a 90-degree elbow cannot be installed, then
a grille of sufficient strength and density should be installed
to prevent objects from falling into the conditioned space.
Due to electric heater, supply duct will require 90-degree
elbow.
CAUTION
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 fork truck when panels or pack-
aging are removed.
If using top crate as spreader bar, once unit is set, carefully
lower wooden crate off building roof top to ground. Ensure
that no people or obstructions are below prior to lowering
the crate.
CAUTION
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 fork truck when panels or pack-
aging are removed.
Summary of Contents for 50HCQA04-06
Page 22: ...22 Fig 36 Electro Mechanical Control Wiring 208 230v 460v ...
Page 23: ...23 Fig 37 Electro Mechanical Control Wiring 575v ...
Page 24: ...24 Fig 38 Electro Mechanical Power Wiring 208 230 1 60 ...
Page 25: ...25 Fig 39 Electro Mechanical Power Wiring 208 230 3 60 ...
Page 26: ...26 Fig 40 Electro Mechanical Power Wiring 460 3 60 ...
Page 27: ...27 Fig 41 Electro Mechanical Power Wiring 575 3 60 ...
Page 28: ...28 Fig 42 PremierLink Wiring Schematic 208 230 460v ...
Page 29: ...29 Fig 43 PremierLink Wiring Schematic 575v ...