Carrier WeatherExpert 48LC Series Installation Instructions Manual page 17

Check tightness of connector lock nuts before connecting gas pip-
ing.
Install a / -in. NPT street elbow on the thru-base gas fitting. At-
3
4
tach a / -in. pipe nipple with minimum length of 16-in. (406 mm)
3
4
(field-supplied) to the street elbow and extend it through the ac-
cess panel at the gas support bracket. (See Fig. 22.)
THRU-BASE
GAS FITTING
Fig. 22 — Gas Line Piping
Other hardware required to complete the installation of the gas
supply line will include a manual shutoff valve, a sediment trap
(drip leg) and a ground-joint union. A pressure regulator valve
may also be required (to convert gas pressure from pounds to
inches of pressure). The manual shutoff valve must be located
within 6 ft (1.83 m) of the unit. The union, located in the final leg
entering the unit, must be located at least 9-in. (230 mm) away
from the access panel to permit the panel to be removed for ser-
vice. If a regulator valve is installed, it must be located a minimum
of 4 ft (1220 mm) away from the unit's flue outlet. Some munici-
pal codes require that the manual shutoff valve be located up-
stream of the sediment trap. See Fig. 23 and 24 for typical piping
arrangements for gas piping that has been routed through the side-
wall of the curb. See Fig. 25 for typical piping arrangement when
thru-base is used. Ensure that all piping does not block access to
the unit's main control box or limit the required working space in
front of the control box.
THRU-CURB ADAPTER
SHUT OFF
VALVE
DRIP
LEG
Fig. 23 — Gas Piping with Direct Drip Leg
GAS
3 / -in NPT
4
SUPPORT
STREET
ELBOW BRACKET
9" (229mm) MIN
UNION
UNIT BASE RAIL
BURNER
ACCESS
PANEL
THRU-CURB ADAPTER
SHUT OFF
Fig. 24 — Gas Piping with Offset Drip Leg
Fig. 25 — Gas Piping Thru-Base Connections
When installing the gas supply line, observe local codes pertaining
to gas pipe installations. Refer to the NFPA 54/ANSI Z223.1
NFGC latest edition (in Canada, CAN/CSA B149.1). In the ab-
sence of local building codes, adhere to the following pertinent
recommendations:
1. Avoid low spots in long runs of pipe. Grade all pipe
in every 15 ft (7 mm in every 5 m) to prevent traps. Grade
all horizontal runs downward to risers. Use risers to con-
nect to heating section and to meter.
2. Protect all segments of piping system against physical and
thermal damage. Support all piping with appropriate
straps, hangers, etc. Use a minimum of one hanger every
6 ft (1.8 m). For pipe sizes larger than
ommendations of national codes.
3. Apply joint compound (pipe dope) sparingly and only to
male threads of joint when making pipe connections. Use
only pipe dope that is resistant to action of liquefied petro-
leum gases as specified by local and/or national codes. If
using PTFE (Teflon
Density type and is labeled for use on gas lines. Apply
tape per manufacturer's instructions.
4. Pressure-test all gas piping in accordance with local and
national plumbing and gas codes before connecting piping
to unit.
1. Teflon is a registered trademark of DuPont.
17
9" (229 mm) MIN
UNION
UNIT BASE RAIL
DRIP
LEG
VALVE
/ -in., follow rec-
1
2
) tape, ensure the material is Double
1
/ -in.
1
4