If a flexible connector is required or allowed 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.
Use the proper length of pipes to avoid stress on the gas
control manifold. Failure to follow this warning can result in
a gas leak, causing fire, explosion, personal injury, or death.
Connect the gas pipe to the furnace using a backup wrench to
avoid damaging furnace gas controls.
Never purge a gas 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 can cause
a fire, explosion, personal injury, or death.
Install a sediment trap in the riser leading to the furnace. The trap
can be installed by connecting a tee to the riser leading from the
furnace. Connect a capped nipple into the lower end of the tee. The
capped nipple should extend below the level of the gas controls.
(See Fig. 8.)
Apply joint compound (pipe dope) sparingly and only to the male
threads of each joint. The compound must be resistant to the action
of propane gas.
An accessible manual shutoff valve MUST be installed upstream
of the furnace gas controls and within 72 in. of the furnace. A
1/8-in. NPT plugged tapping, accessible for test gage connection,
MUST be installed immediately upstream of the gas supply
connection to the furnace and downstream of the manual shutoff
valve. Place ground joint union between the gas control manifold
and the manual shutoff valve.
Piping should be pressure tested in accordance with local and
national plumbing and gas codes before the furnace has been
attached. If the furnace has been attached, it is recommended that
the ground joint union be loosened before pressure testing. If a
subsequent test pressure exceeds 0.5 psig (14-in. wc), the gas
supply pipe must be disconnected from the furnace and capped
before the pressure test. If a subsequent test pressure is equal to or
less than 0.5 psig (14-in. wc), turn off electric shutoff switch
located on the gas valve before the test. After all connections have
been made, purge the lines and check for leakage with regulated
gas supply pressure.
Step 8—Electrical Connections
115-V WIRING
Refer to the unit rating plate or Table 5 for equipment electrical
requirements. The control system requires an earth ground for
proper operation.
Do not connect aluminum wire between disconnect switch
and furnace. Use only copper wire.
Make all electrical connections in accordance with the National
Electrical Code (NEC) ANSI/NFPA 70-1999 in the U.S.A. and
local codes or ordinances that might apply or authorities having
Fig. 7—Leveling Leg Installation
A89014
1
3
⁄
4
″
1
3
⁄
4
″
1
3
⁄
4
″
1
3
⁄
4
″
5
⁄
16
″
5
⁄
16
″
5
⁄
16
″
5
⁄
16
″
Table 4—Maximum Capacity of Gas Pipe*
NOMINAL IRON
PIPE SIZE
(IN.)
INTERNAL
DIAMETER
(IN.)
LENGTH OF PIPE (FT)
10
20
30
40
50
1/2
0.622
175
120
97
82
73
3/4
0.824
360
250
200
170
151
1
1.049
680
465
375
320
285
1-1/4
1.380
1400
950
770
660
580
1-1/2
1.610
2100
1460
1180
990
900
* Cubic 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.
Fig. 8—Typical Gas Pipe Arrangement
A89417
GAS
SUPPLY
MANUAL
SHUTOFF
VALVE
(REQUIRED)
SEDIMENT
TRAP
UNION
8
