Factory-Option Thru-Base Connections (Gas Connections); Equipment Damage - Carrier WeatherExpert 48LC 07 Series Installation Instructions Manual

units, the gas pressure at unit gas connection 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.
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.
3
4
Table 3 — Natural Gas Supply Line Pressure Ranges
UNIT MODEL UNIT SIZE
48LCD/E/S/R0
48LCF/T0
(High Heat units only)
Table 4 — Liquid Propane Supply Line Pressure
Ranges
UNIT MODEL UNIT SIZE
48LCD/F/E/S/R/T0
Manifold pressure is factory-adjusted for natural gas (NG) fuel
use. Adjust as required to obtain best flame characteristics. See
Table 5.
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 5 — Natural Gas Manifold Pressure Ranges
UNIT MODEL UNIT SIZE
48LCD/E/S/R0
48LCF/T0
(High Heat units only)
Table 6 — Liquid Propane Manifold Pressure Ranges
UNIT MODEL UNIT SIZE
48LCD/E/S/R0
48LCF/T0
(High Heat units only)
CAUTION

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. 16.
MIN MAX
4.0 in. wg 13.0 in. wg
07
(996 Pa) (3240 Pa)
5.0 in. wg 13.0 in. Wg
07
(1245 Pa) (3240 Pa)
MIN MAX
11.0 in. wg 13.0 in. wg
07
(2740 Pa) (3240 Pa)
HIGH FIRE LOW FIRE
3.5 in. wg 1.7 in. wg
07
(872 Pa) (423 Pa)
3.5 in. wg 2.0 in. wg
07
(872 Pa) (498 Pa)
HIGH FIRE LOW FIRE
10.0 in. wg 5.0 in. wg
07
(2490 Pa) (1245 Pa)
10.0 in. wg 5.7 in. wg
07
(2490 Pa) (1420 Pa)
1 / -in. Size the
2
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. 16 — 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.
BRASS FITTING FOR 3 TO 6 TON UNITS.
Fig. 17 — Fittings
The thru-base gas connector has male and female threads. The
male threads protrude above the basepan of the unit; the female
threads protrude below the basepan.
Check tightness of connector lock nuts before connecting gas
piping.
Install a 3 / -in. NPT street elbow on the thru-base gas fitting.
4
Attach a / -in. pipe nipple with minimum length of 16-in.
3
4
(406 mm) (field-supplied) to the street elbow and extend it
through the access panel at the gas support bracket. See
Fig. 18.
13
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
/ -in. NPT gas adapt-
3
4
-in. electrical bulkhead connectors and
2
LOW VOLTAGE
CONDUIT
CONNECTOR
HIGH VOLTAGE
CONDUIT
CONNECTOR
*
*