Carrier WeatherMaster 48HC Series Installation Instructions Manual page 18

piping that has been routed through the sidewall of the curb. See
Fig. 27 for typical piping arrangement when thru-base is used. En-
sure 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
Fig. 25 — Gas Piping, Typical Curb Sidewall Piping
BURNER
ACCESS
PANEL
THRU-CURB ADAPTER
Fig. 26 — Gas Piping, Typical Curb Sidewall Piping
Fig. 27 — Gas Piping, Typical Thru-Base
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9" (229mm) MIN
UNION
UNIT BASE RAIL
DRIP
LEG
(Example 1)
9" (229 mm) MIN
UNION
UNIT BASE RAIL
DRIP
LEG
SHUT OFF
VALVE
(Example 2)
Connections
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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:
• Avoid low spots in long runs of pipe. Grade all pipe
per every 15 ft (7 mm per every 5 m) to prevent traps.
Grade all horizontal runs downward to risers. Use risers to
connect to heating section and to meter.
• 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.
• 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
1
Density type and is labeled for use on gas lines. Apply tape
per manufacturer's instructions.
• Pressure-test all gas piping in accordance with local and
national plumbing and gas codes before connecting piping
to unit.
NOTE: Pressure test the gas supply system after the gas supply
piping is connected to the gas valve. The supply piping must be
disconnected from the gas valve during the testing of the piping
systems when test pressure is in excess of 0.5 psig (3450 Pa). Pres-
sure test the gas supply piping system at pressures equal to or less
than 0.5 psig (3450 Pa). The unit heating section must be isolated
from the gas piping system by closing the external main manual
shutoff valve and slightly opening the ground-joint union.
Check for gas leaks at the field-installed and factory-installed
gas lines after all piping connections have been completed. Use
soap-and-water solution (or method specified by local codes
and/or regulations).
Failure to follow this warning could result in personal injury,
death and/or property damage.
• Connect gas pipe to unit using a backup wrench to
avoid damaging gas controls.
• Never purge a gas line into a combustion chamber.
• Never test for gas leaks with an open flame. Use a
commercially available soap solution made specifically
for the detection of leaks to check all connections.
• Use proper length of pipe to avoid stress on gas control
manifold.
NOTE: If orifice hole appears damaged or it is suspected to have
been redrilled, check orifice hole with a numbered drill bit of cor-
rect size. Never redrill an orifice. A burr-free and squarely aligned
orifice hole is essential for proper flame characteristics. See
Fig. 28.
1.Teflon is a registered trademark of DuPont.
18
1 / -in., follow rec-
2
) tape, ensure the material is Double
WARNING
/ -in.
1
4