Bryant 315AAV Return Air Connections, GAS Piping Fire or Explosion Hazard, Furnace Damage Hazard

Return Air Connections

!WARNING

FIRE HAZARD

A failure to follow this warning could cause personal injury, death and/or property damage.

Never connect return-air ducts to the back of the furnace. Follow instructions below.

Downflow Furnaces

The return-air duct must be connected to return-air opening (bottom inlet) as shown in Fig. 3. DO NOT cut into casing sides (left or right). Side opening is permitted for only upflow and certain horizontal furnaces. Bypass humidifier connections should be made at ductwork or coil casing sides exterior to furnace. (See Fig. 19.)

Upflow and Horizontal Furnaces

The return-air duct must be connected to bottom, sides (left or right), or a combination of bottom and side(s) of main furnace casing as shown in Fig. 3. Bypass humidifier may be attached into unused return air side of the furnace casing. (See Fig. 18 and 20.) Not all horizontal furnace models are approved for side return air connections. (See Fig. 20.)

GAS PIPING

!WARNING

FIRE OR EXPLOSION HAZARD

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

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.

!WARNING

FIRE OR EXPLOSION HAZARD

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

Use proper length of pipe to avoid stress on gas control manifold and a gas leak.

!WARNING

FIRE OR EXPLOSION HAZARD

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

Gas valve inlet and/or inlet pipe must remain capped until gas supply line is permanently installed to protect the valve from moisture and debris. Also, install a sediment trap in the gas supply piping at the inlet to the gas valve.

Gas piping must be installed in accordance with national and local codes. Refer to current edition of NFGC in the U.S.

Installations must be made in accordance with all authorities having jurisdiction. If possible, the gas supply line should be a separate line running directly from meter to furnace.

NOTE: In the state of Massachusetts:

1.Gas supply connections MUST be performed by a li- censed plumber or gas fitter.

2.When flexible connectors are used, the maximum length shall not exceed 36 in. (915 mm).

3.When lever handle type manual equipment shutoff valves are used, they shall be T-handle valves.

4.The use of copper tubing for gas piping is NOT approved by the state of Massachusetts.

Refer to Table 6 for recommended gas pipe sizing. Risers must be used to connect to furnace and to meter. Support all gas piping with appropriate straps, hangers, etc. Use a minimum of 1 hanger every 6 ft. (1.8 M). Joint compound (pipe dope) should be applied sparingly and only to male threads of joints. Pipe dope must be resistant to the action of propane gas.

Table 6 – Maximum Capacity of Pipe

NOMINAL	INTERNAL		LENGTH OF PIPE --- FT (M)
IRON PIPE
SIZE	DIA.	10	20	30	40	50
IN. (MM)	IN. (MM)	(3.0)	(6.0)	(9.1)	(12.1)	(15.2)
1/2 (12.7)	0.622(158)	175	120	97	82	73
3/4 (19.0)	0.824 (20.9)	360	250	200	170	151
1 ( 25.4)	1.049 (26.6)	680	465	375	320	285
1-1/4	1.380 (35.0)	1400	950	770	660	580
(31.8)
1-1/2	1.610 (40.9)	2100	1460	1180	990	900
(38.1)

*Cubic ft of gas per hr for gas pressures of 0.5 psig (14--- In. W.C.) or less and a pressure drop of 0.5--- In. W.C. (based on a 0.60 specific gravity gas). Ref: Table 6 and 9.2 NFGC.

!WARNING

FIRE OR EXPLOSION HAZARD

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

If local codes allow the use of a flexible gas appliance connector, always use a new listed connector. Do not use a connector which has previously served another gas appliance. Black iron pipe shall be installed at the furnace gas control valve and extend a minimum of 2-in. (51 mm) outside the furnace.

!CAUTION

FURNACE DAMAGE HAZARD

Failure to follow this caution may result in furnace damage.

Connect gas pipe to furnace using a backup wrench to avoid damaging gas controls and burner misalignment.

An accessible manual equipment shutoff valve MUST be installed external to furnace casing and within 6 ft. (1.8 M) of furnace. A 1/8-in. (3 mm) NPT plugged tapping, accessible for test gauge connection, MUST be installed immediately upstream of gas supply connection to furnace and downstream of manual equipment shutoff valve.

NOTE: The furnace gas control valve inlet pressure tap connection is suitable to use as test gauge connection providing test pressure DOES NOT exceed maximum 0.5 psig (14-In. W.C.) stated on gas control valve. (See Fig. 50.)

Some installations require gas entry on right side of furnace (as viewed in upflow). (See Fig. 21.)

Install a sediment trap in riser leading to furnace as shown in Fig. 22. Connect a capped nipple into lower end of tee. Capped nipple

315AAV

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