Carrier PG92MSA - Page 18

PG92MSA: Installation, Start-up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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hung from floor joists, rafters or trusses or installed on a
non-combustible platform, blocks, bricks or pad.
Supply Air Connections
For a furnace not equipped with a cooling coil, the outlet duct shall be
provided with a removable access panel. This opening shall be
accessible when the furnace is installed and shall be of such a size that
the heat exchanger can be viewed for possible openings using light
assistance or a probe can be inserted for sampling the air stream. The
cover attachment shall prevent leaks.
Connect supply-air duct to flanges on furnace supply-air outlet. Bend
flange upward to 90° with wide duct pliers. See Fig. 20. The supply-air
duct must be connected to ONLY the furnace supply-outlet-air duct
flanges or air conditioning coil casing (when used). DO NOT cut main
furnace casing side to attach supply air duct, humidifier, or other
accessories. All supply-side accessories MUST be connected to duct
external to furnace main casing.
Return Air Connections
The return-air duct can only be connected to bottom of the furnace. The
sides of casing cannot be used for return air connection. See Fig. 23.
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel installed in bottom
return-air opening. Remove and discard this panel when bottom return
air is used. To remove bottom closure panel, see Fig. 24.
Side Return Air Inlet
These furnaces are shipped with bottom closure panel installed in bottom
return-air opening. This panel MUST be in place when side return air
inlet(s) are used without a bottom return air inlet.
Not all horizontal furnaces are approved for side return air connections
See Fig. 23. Where required by code, seal bottom closure to furnace with
tape, mastic, or other durable sealing method.
CAUTION
!
FURNACE RELIABILITY HAZARD
Failure to follow this caution may result in unit component damage.
Return air connections to either side of the furnace in the horizontal
position can result in nuisance limit switch tripping. Use only the
factory bottom opening of the furnace for the return air connection.
Table 6 – Opening Dimensions - In. (mm)
FURNACE
CASING WIDTH
IN. (mm)
APPLICATION
PLENUM OPENING FLOOR OPENING
A B C D
14–3/16
*
(360)
*. Not all families have these models
Upflow Applications on Combustible or Noncombustible Flooring
(Subbase not required)
12-11/16
(322)
21-5/8
(549)
13-5/16
(338)
22-1/4
(565)
Downflow Applications on Noncombustible Flooring
(Subbase not required)
12-9/16
(319)
19
(483)
13-3/16
(335)
19-5/8
(498)
Downflow applications on combustible flooring
(Subbase required)
11-13/16
(284)
19
(483)
13-7/16
(341)
20-5/8
(600)
Downflow Applications on Combustible Flooring with coil assembly
coil or coil box (Subbase not required)
12-5/16
(319)
19
(483)
13-5/16
(338)
20
(508)
17–1/2
(445)
Upflow Applications on Combustible or Noncombustible Flooring
(Subbase not required)
16
(406)
21-5/8
(549)
16-5/8
(422)
22-1/4
(565)
Downflow Applications on Noncombustible Flooring
(Subbase not required)
15-7/8
(403)
19
(483)
16-1/2
(419)
19-5/8
(498)
Downflow applications on combustible flooring
(Subbase required)
15-1/8
(384)
19
(483)
16-3/4
(425)
20-5/8
(600)
Downflow Applications on Combustible Flooring with coil assembly
coil or coil box (Subbase not required)
15-1/2
(394)
19
(483)
16-1/2
(419)
20
(508)
21
(533)
Upflow Applications on Combustible or Noncombustible Flooring
(Subbase not required)
19-1/2
(495)
21-5/8
(549)
20-1/8
(511)
22-1/4
(565)
Downflow Applications on Noncombustible Flooring
(Subbase not required)
19-3/8
(492)
19
(483)
20
(508)
19-5/8
(498)
Downflow applications on combustible flooring
(Subbase required)
18-5/8
(473)
19
(483)
20-1/4
(514)
20-5/8
(600)
Downflow Applications on Combustible Flooring with coil assembly
coil or coil box (Subbase not required)
19
(483)
19
(483)
20
(508)
20
(508)
24-1/2
(622)
Upflow Applications on Combustible or Noncombustible Flooring
(Subbase not required)
23
(584)
21-1/8
(537)
23-5/8
(600)
22-1/4
(565)
Downflow Applications on Noncombustible Flooring
(Subbase not required)
22-7/8
(581)
19
(483)
23-1/2
(597)
19-5/8
(498)
Downflow applications on Combustible flooring
(Subbase required)
22-1/8
(562)
19
(483)
23-3/4
(603)
20-5/8
(600)
Downflow Applications on Combustible Flooring with coil assembly
coil or coil box (Subbase not required)
22-1/2
(572)
19
(483)
23-1/2
(597)
20
(508)