Positioning On Curb; Step 7 - Horizontal Duct Connection; Step 8 - Install Outside Air Hood - Factory Option - Carrier WeatherExpert 48LC Installation Instructions Manual

Positioning on Curb —
Position unit on roof curb so that the following clearances
1
are maintained: / in. (6 mm) clearance between the roof
4
curb and the base rail inside the right and left,
(12 mm) clearance between the roof curb and the base rail
inside the front and back. This will result in the distance
between the roof curb and the base rail inside on the
condenser end of the unit being approximately equal to
Details A and B in Fig. 8, 9 and 10.
Do not attempt to slide unit on curb after unit is set. Doing
so will result in damage to the roof curb seal.
Although unit is weatherproof, guard against water from
higher level runoff and overhangs.
Flue vent discharge must have a minimum horizontal
clearance of 48 in. (1220 mm) from electric and gas meters,
gas regulators, and gas relief equipment. Minimum distance
between unit and other electrically live parts is 48 inches
(1220 mm).
Flue gas can deteriorate building materials. Orient unit such
that flue gas will not affect building materials. Locate
mechanical draft system flue assembly at least 48 in.
(1220 mm) from an adjacent building or combustible
material.
After unit is in position, remove rigging skids and
shipping materials.
Step 7 — Horizontal Duct Connection
Refer to Fig. 2, 3 and 4 for locations and sizes of the
horizontal duct connections. Note that there are two different
return air duct connection locations – one for unit without an
economizer (on back side of unit) and a different one for
unit equipped with an economizer (on left end, under the
economizer hood). The supply air duct connection is on the
back side. See Fig. 12 for top view depicting typical
horizontal duct arrangements.
Horizontal
Supply Air
Supply
Location Back
7
Height --- In. (mm) 15 / (402)
8
3
Width --- in. (mm) 29 / (756)
4
Fig. 12 - - Horizontal Duct Opening Dimensions
1
/ in.
2
Return Air Duct Return Air Duct
without with Economizer
Economizer
C10626
Return without Return with
Economizer Economizer
Back Left end
3 3
49 / (1253) 18 / (467)
8 8
3 5
23 / (593) 61 / (1564)
8 8
(3
Field- - supplied / - - inch) flanges should be attached to
4
horizontal duct openings (see Fig. 12) and all ductwork
should be secured to the flanges. Insulate and weatherproof
all external ductwork, joints, and roof or building openings
with counter flashing and mastic in accordance with
applicable codes.
Step 8 — Install Outside Air Hood — Factory
Option
The outside air hood for factory- - option economizer is
shipped in knock- - down form and requires field assembly.
The panel for the hood top is shipped on the end of the
unit (see Fig. 13). The remaining parts for the hood
assembly (including side panels, filters and tracks) are
shipped in a carton that is secured to the rear of the blower
assembly. Access the carton location through rear panel
(see Fig. 14).
Hood Top
Shipping
Position
Fig. 13 - - Hood Top – Shipping Position
To remove the hood parts package:
1. Remove the back blower access panel.
2. Locate and cut the strap, being careful to not damage
any wiring.
3. Carefully lift the hood package carton through the
back blower access opening.
See Fig. 15 for identification of the various parts of the
hood assembly.
Hood
Package
Fig. 14 - - Hood Package – Shipping Location
21
C09134
C09133