Gas Piping; Reversing Procedure - Bryant 349HAV Series Installation, Start-Up, And Operating Instructions Manual

TABLE 3—MAXIMUM CAPACITY OF PIPE*
NOMINAL
IRON
INTERNAL
PIPE
DIAMETER (IN.)
SIZE
(IN.)
1/2 0.622
3/4 0.824
1 1.049
1-1/4 1.380
1-1/2 1.610
*Cu ft of gas per hr for gas pressures of 0.5 psig (14-in. wc) or less, and a
pressure drop of 0.5-in. wc (based on a 0.60 specific gravity gas). Ref: Table
10-2 NFPA 54-1996.
NOTE: In order to make proper adjustments, minimum and
maximum gas supply pressure limits shown on rating plate must
not be exceeded.
Install a sediment trap in riser leading to furnace. The trap can be
installed by connecting a tee to riser leading to furnace, so that the
straight-through section of tee is vertical.
Then connect a capped nipple into lower end of tee. The capped
nipple should extend below the level of gas controls. Place a
ground joint union between gas control manifold and manual gas
shutoff valve. (See Fig. 4.)
GAS
SUPPLY
MANUAL
SHUTOFF
VALVE
SEDIMENT
TRAP
THIS DRIP LEG MUST BE
INSTALLED WITH THE PIPE
CAP A MINIMUM OF 1 IN.
FROM FLOOR TO PERMIT
REMOVAL
Fig. 4—Typical Gas Piping
CAUTION: If a flexible connector is required or al-
lowed by the authority having jurisdiction, black iron
pipe shall be installed at the gas valve and extend a
minimum of 2 in. outside the furnace casing.
An accessible manual shutoff valve MUST be installed upstream
of furnace gas controls and within 72 in. of furnace. A 1/8-in. NPT
plugged tapping, accessible for test gage connection, MUST be
installed immediately upstream of gas supply connection to
furnace and downstream of manual shutoff valve. (The manifold
pressure tap on gas control meets this requirement.)
WARNING: Use the proper length of pipes to avoid
stress on the gas control manifold. A failure to follow this
warning could result in a gas leak resulting in a fire,
explosion, personal injury, or death.
Before any system of gas piping is finally put into service, it
should be carefully tested to determine if it is gas tight. The piping
must stand a pressure of 6 in. of mercury for a period of 10 minutes
or as required by local authority.
LENGTH OF PIPE (FT)
10 20 30 40 50
175 120 97 82 73
360 250 200 170 151
680 465 375 320 285
1400 950 770 660 580
2100 1460 1180 1993 900
UNION
A96071
Piping should be pressure tested in accordance with local and
national plumbing and gas codes before furnace has been attached.
If test pressure exceeds 0.5 psig (14-in. wc), the gas supply pipe
must be disconnected from furnace and capped before pressure
test. If test pressure is equal to or less than 0.5 psig (14-in. wc),
close manual shutoff valve located on gas valve before pressure
test. It is recommended that the ground joint union be loosened
before pressure testing.
CAUTION: Use a backup wrench when connecting the
gas pipe to the furnace to avoid damaging gas controls.
After all connections have been made, purge the lines and check
for leakage.
WARNING: Never purge a line into a combustion
chamber. Never use matches, candles, flame, or other
sources of ignition for the purpose of checking leakage.
Use a soap-and-water solution to check for leakage.
Failure to follow this warning could result in a fire,
explosion, personal injury, or death.
VI. REVERSING PROCEDURE
WARNING: Before proceeding with field reversal, en-
sure that all electrical power is turned off and that all gas
piping is shut off and disconnected from the furnace.
Failure to do so could result in an extremely hazardous
condition and bodily harm.
This furnace may be field reversed allowing for a horizontal right
configuration (left-to-right airflow) instead of the factory posi-
tioned horizontal left configuration (right-to-left airflow). (See Fig.
5.) Field reversal is accomplished in a convenient 3-step process.
1. Invert furnace so top panel is down.
2. Adjust manifold and burner opening plate.
3. Wire alternate limit switch.
A. Invert The Furnace
1. Carefully flip furnace on its top panel. Care should be taken
not to drop unit or let it rest on 1 of its ends.
2. Controls should now appear as in right-hand view of Fig. 5.
B. Adjust Manifold and Burner Opening Plate
1. Remove front and back burner removal covers located on
front and rear center panels.
2. Cut wire tie securing violet-colored rollout switch wires and
ignition wire to manifold assembly.
3. Disconnect all wires from gas valve.
CAUTION: Label all wires prior to disconnection when
servicing controls. Wiring errors can cause improper and
dangerous operation.
4. Remove both manifold retention places from burner box
and remove burner/manifold assembly. While removing
burner/manifold assembly, disconnect violet-colored rollout
switch wires from rollout switch. (See Fig. 6.)
5. On burner/manifold assembly, remove 2 screws that fasten
rollout switch bracket to rollout switch base bracket. (See
Fig. 7.)
—7—