1. Construct a working platform on location where all required
furnace clearances are met. (See Table 1 and Fig. 2.)
2. Position furnace in desired location.
3. Connect gas supply pipe. See Fig. 2 for typical gas piping.
4. Connect supply- and return-air ducts.
5. Install 24- X 24-in. sheet metal shield on platform in front of
controls as shown in Fig. 2.
Step 3—Horizontal Crawlspace Installation
The furnace can be installed horizontally for either left- or
right-side supply. In a crawlspace, the furnace can either be hung
from the floor joists or installed on suitable blocks or a pad. The
furnace can be suspended using steel pipe straps around each end
of the furnace. These straps should be attached to the furnace with
sheet metal screws and to the floor joists with lag bolts. A framed
assembly of angle iron suspended with all-thread rod of suitable
diameter may be used to support the length of the furnace.
The horizontal crawlspace installation is very similar to the attic.
Refer to Step 2, items 2, 3, 4, and 5. A 24- X 24-in. sheet metal
shield must be installed above the controls for crawlspace instal-
lations. Extend the sheet metal shield over the furnace top far
enough to cover the gas pipe entry hole.
Step 4—Filter Arrangement
Never operate the unit without a filter or with the filter
removed. Failure to follow this caution can result in a fire,
personal injury, or death.
The factory-supplied filter and wire filter retainer are shipped with
the furnace. After the return-air duct has been connected to the
furnace, install the filter in the blower compartment, just ahead of
the return-air plenum, and secure it with the wire filter retainer.
The cross-mesh binding side of the filter should face the blower.
Step 5—Gas Piping
Gas piping must be installed in accordance with national and local
codes. Refer to the current edition of the NFGC.
The gas supply line should be a separate line running directly from
the meter to the furnace, if possible. Refer to Table 3 for the
recommended gas pipe sizing. Risers must be used to connect to
the furnace and to the meter.
Table 3—Maximum Capacity of Pipe*
NOMINAL
IRON
PIPE
SIZE
(IN.)
INTERNAL
DIAMETER (IN.)
LENGTH OF PIPE (FT)
10
20
30
40
50
1/2
0.622
200
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 54-1992.
Support all piping with appropriate straps, hangers, etc. Use a
minimum of 1 hanger every 6 ft.
Joint compounds (pipe dope) should be applied sparingly and only
to the male threads of the joints. This pipe dope must be resistant
to the action of propane gas.
Install a sediment trap in the riser leading to the furnace. The trap
can be installed by connecting a tee to the riser leading to the
furnace, so that the straight-through section of the tee is vertical.
Connect a capped nipple to the lower end of the tee. The capped
nipple should extend below the level of the gas controls. Place a
ground joint union between the gas control manifold and the
manual gas shut-off valve. (See Fig. 3.)
An accessible manual shut-off valve MUST be installed upstream
of the furnace gas controls and within 6 ft 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 shut-off valve.
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 causing fire, explosion, personal injury, or death.
Piping should be pressure tested in accordance with local and
national plumbing and gas codes before the furnace has been
attached. If the 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 the test pressure is equal to or less than
0.5 psig (14-in. wc), close the manual shut-off valve located on the
gas valve before the test. It is recommended that the ground joint
union be loosened before pressure testing.
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.
Never purge a line into a combustion chamber. Never use
matches, candles, flame, or other sources of ignition to check
for leaks. 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.
Step 6—Electrical Connections
See Fig. 17 for a wiring diagram showing the proper field 115- and
24-v wiring. Check all factory and field electrical connections for
tightness.
115-V WIRING — Before proceeding with the electrical connec-
tions, make certain that voltage, frequency, and phase correspond
to that specified on the unit rating plate. Also, check to be sure that
the service provided by the utility is sufficient to handle the load
imposed by this equipment. Refer to rating plate or to Table 4 for
the equipment electrical specifications.
Fig. 3—Typical Gas Piping
A91212
GAS
SUPPLY
MANUAL
SHUTOFF
VALVE
SEDIMENT
TRAP
UNION
4
