Carrier 48DH - Manual (Page 3)

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Ductwork Installation — For air duct system design
information, refer to Carrier System Design Man­
ual, Part 2. System air flow must be within the
range of temperature rise and external static
pressure shown on the unit A.G.A. rating plate.
Bolt or screw ductwork to unit supply and
return air duct flanges and seal joints with sheet
metal flashing. Flange location and dimensions are
given in Fig. 1 and Table 1. Use flexible connectors
between ductwork and unit to dampen vibration.
If a single split duct is connected to the unit, use a
gasket to prevent air bypass between supply and
return sides.
Insulate and weatherproof all external duct­
work. Secure ducts to building structure and
weatherproof all duct openings in wall or roof.
Ducts passing thru unconditioned spaces must be
insulated and provided with a vapor barrier.
Filter Installation (Field-Supplied)
1. Locate filter in return air system. Convenient
location for filter is inside building behind
return air grille. Size and number of required
filters is given in Table 2.
2. Attach filter manufacturer’s instructions to
filter rack.
ASSEMBLE WIND CAP AND
COMBUSTION-AIR INLET BOX
Locate — The wind cap assembly, heat-shield collar
and combustion-air inlet box (items 1, 2 and 3 of
Fig. 2) are shipped within the condenser section of
all size 003 thru 005 units except 460 volt unit.
On 460 volt, size 003 thru 005 units, only the
combustion-air inlet box is shipped within the
condenser section. The heat-shield collar and wind
cap assembly are shipped in a separate package.
On size 002 units of any voltage, the
combustion-air inlet box is inside the unit behind
the heating section access panel (Fig. 1). The
heat-shield collar and wind cap assembly are
shipped in a separate package.
Remove — On size 002 units, remove the heating
section access panel (Fig. 1) and obtain the
combustion-air inlet box.
On size 003 thru 005 units, remove 6 sheet
metal screws and lift condenser fan, grille and
orifice from the top of the condenser section (Fig.
3). Remove and discard metal banding securing the
wind cap and/or inlet box and remove the item(s)
from the condenser section.
Before replacing the condenser fan, grille and
orifice, remove any shipping tape from the con­
denser fan.
Assemble (Fig. 2)
1. Mount the combustion-air inlet box (item 3) by
sliding the horizontal box flange under the
retaining clip on the unit top cover. Fasten the
inlet box with sheet metal screws provided.
2. Place end of heat-shield collar (item 2) over top
cover extrusion.
3. Slide flue pipe into heat-shield collar and secure
wind cap assembly (item 1) with 3 sheet metal
screws thru wire cage eyelets.
WIND CAP
ASSEMBLY
FLUE PIPE
(PART OF WIND CAP
ASSEMSLY)
£Y£LETS(3)
■JXHEAT-SHIELC
^COLLAR
COMBUSTION
AIR INLET BOX
RETAINJNO
CLIP
TOP COVER
OF UNIT
TOP COVER
EXTRUSION
FLUE BOX
EXTRUSION
HEATING SECTION
ACCESS PANEL
Fig. 2 — Wind Cap and Air Inlet Box Assembly
Fig. 3 — Removing Condenser Fan
and Orifice Assembly
PIPING AND WIRING
Gas Piping — Install piping per national and local
codes and ANSI Z223.1 entitled “Installation of
Gas Appliances and Gas Piping,” (published by
American Gas Association, 1515 Wilson Blvd.,
Arlington (Rosslyn), Va. 22209).