Step 9 - Install Flue Hood; Step 10 - Install Gas Piping - Carrier WeatherMaster 48HC14 Installation Instructions Manual

Step 9 — Install Flue Hood —
shipped screwed to the basepan beside the burner compartment
access panel. Remove the panel below the control box access
panel to access the flue hood shipping location. Using screws
provided, install flue hood and screen in location shown in
Fig. 16.
Fig. 16 — Flue Hood Details
Step 10 — Install Gas Piping —
gas piping must be accordance with local building codes and
with applicable national codes. In U.S.A., refer to NFPA 54/
ANSI Z223.1 National Fuel Gas Code (NFGC). In Canada, in-
stallation must be in accordance with the CAN/CSA B149.1
and CAN/CSA B149.2 installation codes for gas burning appli-
ances.
This unit is factory equipped for use with Natural Gas fuel
at elevations up to 2000 ft (610 m) above sea level. Unit may
be field converted for operation at elevations above 2000 ft
(610 m) and/or for use with liquefied petroleum fuel. See ac-
cessory kit installation instructions regarding these accessories.
NOTE: In U.S.A. the input rating for altitudes above 2000 ft
(610 m) must be derated by 4% for each 1000 ft (305 m) above
sea level. In Canada the input rating must be derated by 10%
for altitudes of 2000 ft (610 m) to 4500 ft. (1372 m) above sea
level.
For natural gas applications, gas pressure at unit gas connec-
tion must not be less than 5 in. wg (1250 Pa) or greater than 13
in. wg (3240 Pa) while the unit is operating. For liquified
petroleum applications, the gas pressure must not be less than
11 in. wg (2740 Pa) or greater than 13 in. wg (3240 Pa) at the
unit connection.
Table 2 — Natural Gas Supply Line Pressure
Ranges
UNIT MIN
48HC**14 5.0 in. wg (1250 Pa)
Table 3 — Liquid Propane Supply Line Pressure
Ranges
UNIT MIN
48HC**14 11.0 in. wg (2740 Pa)
The gas supply pipe enters the unit at the burner access pan-
el on the front side of the unit, through the long slot at the
The flue hood is
CONTROL BOX
ACCESS PANEL
FLUE
HOOD
Installation of the
MAX
13.0 in. wg (3240 Pa)
MAX
13.0 in. wg (3240 Pa)
13
bottom of the access panel. The gas connection to the unit is
made to the 3 / -in. FPT gas inlet port on the unit gas valve.
4
Manifold pressure is factory-adjusted for NG fuel use. Ad-
just as required to obtain best flame characteristics.
Table 4 — Natural Gas Manifold Pressure Ranges
UNIT MODEL HIGH FIRE
48HC**14 3.5 in. wg (872 Pa)
Manifold pressure for LP fuel use must be adjusted to spec-
ified range. Follow instructions in the accessory kit to make
initial readjustment.
Table 5 — Liquid Propane Manifold Pressure
Ranges
UNIT HIGH FIRE
48HC**14 10.0 in. wg (2490 Pa)
CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in damage to
equipment.
When connecting the gas line to the unit gas valve, the
installer MUST use a backup wrench to prevent damage to
the valve.
Install a gas supply line that runs to the unit heating section.
Refer to the NFPA 54/NFGC or equivalent code for gas pipe
sizing data. Size the gas supply line to allow for a maximum
pressure drop of 0.5-in. wg (124 Pa) between gas regulator
source and unit gas valve connection when unit is operating at
high-fire flow rate.
The gas supply line can approach the unit in three ways:
horizontally from outside the unit (across the roof), thru-curb/
under unit basepan (accessory kit required) or through unit
basepan (factory-option or accessory kit required). Consult ac-
cessory kit installation instructions for details on these installa-
tion methods. Observe clearance to gas line components per
Fig. 17.
9" MINIMUM CLEARANCE
FOR PANEL REMOVAL
MANUAL GAS
SHUTOFF VALVE
BASE UNIT
48" MINIMUM
BASE RAIL
ROOF
CURB
FROM
GAS
METER
LEGEND
NFGC — National Fuel Gas Code
* Field supplied.
NOTE: Follow all local codes.
STEEL PIPE NOMINAL
DIAMETER (in.)
1
/
2
3
/ or 1
4
1 1 / or larger
4
Fig. 17 — Gas Piping Guide
LOW FIRE
2.0 in. wg (498 Pa)
LOW FIRE
5.7 in. wg (1420 Pa)
X
GAS
*
REGULATOR
*
DRIP LEG
*
PER NFGC
FIELD-FABRICATED
SUPPORT *
SPACING OF SUPPORTS X
DIMENSION (ft)
6
8
10