Carrier NP034-074 - Manual (Page 36)

Gas Piping (48 Series Units Only) — Unit is equipped
for use with natural gas only. Installation must conform with
local building codes, or in the absence of local codes, with
the National Fuel Gas Code, ANSI Z223.1.
A 1/8-in. NPT tapping plug, accessible for test gage con-
nection, must be field installed immediately upstream of gas
supply connection to unit, but after manual gas valve. See
Fig. 21. Natural gas pressure at unit gas connection must not
be less than 5 in. wg or greater than 13 in. wg.
Size gas supply piping for 0.5 in. wg maximum pressure
drop. Do not use supply pipe smaller than unit gas
connection.
Disconnect gas piping from unit when leak testing at
pressures greater than 0.5 psig. Pressures greater than
0.5 psig will cause gas valve damage resulting in a haz-
ardous condition. If gas valve is subjected to pressure
greater than 0.5 psig, it must be replaced.
Installing Flue/Inlet Hoods (48 Series Units Only)
—
The flue/inlet hoods are shipped in a bag taped to the
basepan in the gas section.
UNIT SIZES 034 AND 044 — The 48 series units have 2
inlet hoods, 2 flue hoods, and 2 flue deflector hoods. See
Fig. 22. The 48 series low-heat units have one inlet hood,
one flue hood and one flue deflector hood.
Remove shipping block-offs and shipping tape from open-
ings in access panel. Inlet hoods are shipped unassembled
and must be assembled in place. See Fig. 23. The inlet hood
consists of a hood, 2 side plates, and an inlet screen.
Install inlet hoods using screws provided.
NOTE: Hoods must be assembled in place on the access panel.
Flanges on hood and side plates go to the inside of the ac-
cess panel.
Install inlet screen on each inlet hood using speed clips
and screws provided. Attach flue hoods (see Fig. 24) to ac-
cess panel using screws provided. Hoods go over each com-
bustion air outlet.
Sub-assemble flue deflector baffle inside the flue deflector
hood as shown in Fig. 25 and 26. Flue deflector baffle must
be assembled and installed on the access panel so that the
holes in the mounting flange are at the bottom. Install flue
deflector hood over flue hoods. Be sure that deflector scoop
is pointed up.
UNIT SIZES 054-074 — The 48 series high-heat units have
2 large inlet hoods, 2 small inlet hoods, 3 flue hoods, and
3 flue deflector hoods. See Fig. 27 and 28. The 48 series
low-heat units have one large inlet hood, 2 small inlet hoods,
2 flue hoods, and 2 flue deflector hoods. (See Fig. 27
and 28).
Remove shipping block-offs and shipping tape from open-
ings in access panels. Inlet hoods are shipped unassembled
and must be assembled in place. See Fig. 23. Inlet hoods
consist of a hood, 2 side plates, and an inlet screen.
Install large and small inlet hoods using screws provided.
NOTE: Hoods must be assembled in place on the access panel.
Flanges on hood and side plates go to the inside of the ac-
cess panel.
Install inlet screen in each inlet hood using speed clips
and screws provided. Attach flue hoods (see Fig. 24) to ac-
cess panel using screws provided. Hoods go over each com-
bustion air outlet.
Sub-assemble flue deflector baffle inside flue deflector hood
as shown in Fig. 29. Install flue deflector hoods over flue
hoods. (See Fig. 27.)
NOTE: Be sure deflector hoods are installed as shown and
not upside down. The holes in the mounting flange must be
at the bottom when installed on access panel.
*NPT plug is field supplied.
NOTE: Follow all local codes.
Fig. 21 — Gas Piping Details
FLUE HOOD AND
FLUE DEFLECTOR
HOOD (48 SERIES
HIGH-HEAT ONLY)
INLET HOOD
(48 SERIES HIGH-
HEAT ONLY)
FLUE HOOD AND
DEFLECTOR
HOOD
INLET HOOD
Fig. 22 — Flue/Inlet Hood, 034,044 Units
INLET HOOD
INLET HOOD
SIDE PLATE
(TYP EACH SIDE)
Fig. 23 — Inlet Hood
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