Factory-Option Thru-Base Connections (Gas Connections) - Carrier WeatherExpert 48LC 04 Series Installation Instructions Manual

This unit is factory-equipped for use with natural gas (NG) 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: Furnace gas input rate on rating plate is for installation up
to 2000 ft (610 m) above sea level. 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 4 in. wg (996 Pa) or greater than
13 in. wg (3240 Pa) while the unit is operating. On 48LCF/N/
T*05-06 (high-heat) units, the gas pressure at unit gas connec-
tion must not be less than 5 in. wg (1245 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 13.0 in. wg (3240 Pa) at the
unit connection. See Tables 3 and 4.
Table 3 — Natural Gas Supply Line Pressure Ranges
UNIT
UNIT MODEL
SIZE
48LCD/E/L/M/S/R 04, 05, 06
48LCF/N/T
(High Heat units 05, 06
only)
Table 4 — Liquid Propane Supply Line Pressure
Ranges
UNIT MODEL UNIT SIZE
48LCD/E/S/R 04, 05, 06
48LCF/T
(High Heat units only)
The gas supply pipe enters the unit at the burner access panel
on the front side of the unit, through the long slot at the bottom
of the access panel. The gas connection to the unit is made to
the / -in. FPT gas inlet port on the unit gas valve.
1
2
Manifold pressure is factory-adjusted for NG fuel use. Adjust
as required to obtain best flame characteristics. See Table 5.
Table 5 — Natural Gas Manifold Pressure Ranges
UNIT MODEL UNIT SIZE
48LCD/E/L/M/S/R 04, 05, 06
48LCF/N/T
(High Heat units only)
Manifold pressure for liquid propane (LP) fuel use must be ad-
justed to specified range. Follow instructions in the accessory kit
to make initial readjustment. See Table 6.
Table 6 — Liquid Propane Manifold Pressure Ranges
UNIT MODEL UNIT SIZE
48LCD/E/S/R 04, 05, 06
48LCF/T
(High Heat units only)
MIN MAX
4.0 in. wg (996 13.0 in. wg (3240
Pa) Pa)
5.0 in. wg 13.0 in. wg
(1245 Pa) (3240 Pa)
MIN MAX
11.0 in. wg 13.0 in. wg
(2740 Pa) (3240 Pa)
11.0 in. wg 13.0 in. wg
05, 06
(2740 Pa) (3240 Pa)
HIGH FIRE LOW FIRE
3.5 in. wg 1.7 in. wg
(872 Pa) (423 Pa)
3.5 in. wg 1.7 in. wg
05, 06
(872 Pa) (423 Pa)
HIGH FIRE LOW FIRE
10.0 in. wg 5.0 in. wg
(2490 Pa) (1245 Pa)
10.0 in. wg 5.0 in. wg
05, 06
(2490 Pa) (1245 Pa)
EQUIPMENT DAMAGE
Failure to follow this caution may result in equipment damage.
When connecting the gas line to the unit gas valve, the in-
staller 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. Do not use a pipe size smaller than
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: hori-
zontally 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 accessory
kit installation instructions for details on these installation
methods. Observe clearance to gas line components per
Fig. 20.
9" MINIMUM CLEARANCE
FOR PANEL REMOVAL
BASE UNIT
BASE RAIL
ROOF
CURB
FROM
GAS
NFGC – National Fuel Gas Code
METER
* Field supplied.
NOTE: Follow all local codes.
STEEL PIPE
NOMINAL DIAMETER
(in.)
1 /
2
3
/
or 1
4
1
/
1 or larger
4
Fig. 20 — Gas Piping Guide (with Accessory
Thru-the-Curb Service Connections)
FACTORY-OPTION THRU-BASE CONNECTIONS (GAS
CONNECTIONS)
This service connection kit consists of a
er fitting (brass), two 1 /
a 3 / -in. electrical bulkhead connector, all factory-installed in
4
the embossed (raised) section of the unit basepan in the con-
denser section.
15
CAUTION
/
1
2
X
GAS
REGULATOR
MANUAL GAS
SHUTOFF VALVE *
48" MINIMUM
DRIP LEG
*
PER NFGC
FIELD-FABRICATED
SUPPORT
LEGEND
SPACING OF SUPPORTS
X DIMENSION
(ft)
6
8
10
1 / -in. NPT gas adapt-
2
-in. electrical bulkhead connectors and
2
-in. Size the
*
*