Step 5 - Install Curb Gasketing; Step 6 - Install Field-Fabricated Ductwork; Step 7 - Rig Unit - Carrier WeatherExpert 48N2 Installation Instructions Manual

Step 5 — Install Curb Gasketing
After ductwork has been connected to the roof curb, apply gasket
material ( / -in. thick x 1 / -in. wide neoprene) where indicated.
1 1
2 2
Single-Thickness Gasketing (See Fig. 5 for Item Numbers)
Apply gasketing in the following places:
1. Along both side rails (1) — 2 places, full length
2. Along return air end rail (2) — 1 place
3. Around return air internal duct flange (3) — 1 or 2 places
4. Around supply air internal duct flanges (4) — 3 places
5. Along supply section base rail (5) — 1 place
Condenser Section Roof Curb (See Fig. 6)
Apply single-thickness gasket along both side rails (5).
Step 6 — Install Field-Fabricated Ductwork
WARNING
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 a 90 degree turn in
the return ductwork between the unit and the conditioned
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.
.
3
RETURN
2
Fig. 5 — Gasket Location on Roof Curb
5
Fig. 6 — Gasket Location — Condenser Section Roof Curb
Field-fabricated ductwork for vertical supply/vertical return units
must be attached to the roof curb, or to the support steel, prior to
the final rigging and installation of the unit. Supply and return duct
dimensions are shown in Fig. 3.
To attach ductwork to roof curb, insert duct approximately 10 to
11 in. up into roof curb. Connect ductwork to 14-gage roof curb
material with sheet metal screws driven from inside the duct.
Secure all ducts to the building structure, using flexible duct con-
nectors between roof curbs and ducts as required. Ducts passing
through an unconditioned space must be insulated and covered
with a vapor barrier. Outlet grilles must not lie directly below unit
discharge.
Design supply duct strong enough to handle expected static pres-
sures. Field-fabricated ductwork for horizontal supply/return units
must be attached to the unit.
Step 7 — Rig Unit
Do not drop unit; keep upright. Use spreader bars over the unit to
prevent sling or cable damage. Sheets of plywood placed along
the condenser coils will provide additional protection. All lifting
lugs MUST be used when lifting unit. Level by using unit frame
as a reference. See Fig. 7-9 for information. Unit and accessory
weights are shown in Tables 1 and 2. Weight distribution and cen-
ter of gravity can be found in Fig. 10. Additional unit dimensional
data can be found in Fig. 11-13.
SUPPLY
4
1
5
18
5 ALONG SUPPLY
SECTION END RAIL