48HC

Factory-Option Thru-Base Connections —

Electrical Connections: Knockouts are located in the control box area. Remove the appropriate size knockout for high voltage connection. Use the field supplied connector depending on wiring or conduit being utilized. Remove the 7/8-in (22mm) knockout and appropriate connector for low voltage wiring. If non-unit powered convenience outlet is being utilized, remove the 7/8-in (22mm) knockout and utilize appropriate connector for 115 volt line. See “Step 12 — Making Electrical Connections” for details.

Gas Connections: Remove the knockout in the base pan and route 3/4-in. gas line up through the opening. Install an elbow and route gas line through opening in panel after first removing plastic bushing. Install a gas shut off followed by a drip leg and ground-joint union. Route gas line into gas section through the grommet (Part #: KA56SL112) at the gas inlet and into the gas valve. See Fig. 17 and Table 2. If a regulator is installed, it must be located 4 feet (1.22 meters) from the flue outlet.

Some municipal codes require that the manual shutoff valve be located upstream of the sediment trap. See Fig. 18 for typical piping arrangements for gas piping that has been routed through the sidewall of the base pan.

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 absence of local building codes, adhere to the following pertinent recommendations:

1.

Avoid low spots in long runs of pipe. Grade all pipe

 

1/4-in. in every 15 ft (7 mm in every 5 m) to prevent

 

traps. Grade all horizontal runs downward to risers.

 

Use risers to connect to heating section and to meter.

2.

Protect all segments of piping system against physical

 

and thermal damage. Support all piping with appro-

 

priate straps, hangers, etc. Use a minimum of one

 

hanger every 6 ft (1.8 m). For pipe sizes larger than

 

1/2-in., follow recommendations 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 lique-

 

fied petroleum gases as specified by local and/or nation-

 

al codes. If using PTFE (Teflon) tape, ensure the materi-

 

al is Double 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 connect-

 

ing 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). Pressure 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).

!WARNING

FIRE OR EXPLOSION HAZARD

Failure to follow this warning could result in personal injury, death and/or property damage.

SConnect gas pipe to unit using a backup wrench to

avoid damaging gas controls.

SNever purge a gas line into a combustion chamber. S 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.

S 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 correct size. Never redrill an orifice. A burr-free and squarely aligned orifice hole is essential for proper flame characteristics.

BURNER

ORIFICE

Fig. 20 - Orifice Hole

A93059

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Carrier 48HC installation instructions Factory-Option Thru-Base Connections, Orifice Hole

48HC specifications

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