035-17438-001 Rev. A (901)
Unitary Products Group
11
GAS PIPING
NOTE:
An accessible manual shutoff valve must be
installed upstream of the furnace gas controls and within 6
feet of the furnace
.
The furnace and its individual shutoff valve must be discon-
nected from the gas supply piping system during any pres-
sure testing of that system at test pressures in excess of 1/2
psig (3.48 kPa).
The furnace must be isolated from the gas supply piping sys-
tem by closing its individual external manual shutoff valve
during any pressure testing of the gas supply piping system
at test pressures equal to or less than 1/2 psig (3.48 kPa).
Gas piping may be connected from either side of the furnace.
Sizing and installation of the supply gas line should comply
with the local utility requirements.
The gas supply should be a separate line, installed in accor-
dance with the National Fuel Gas Code, ANSI Z223.1, or
CAN/CGA B149.1 or .2 Installation Codes (latest editions).
Some utility companies, or local codes, require pipe sizes
larger than the minimum sizes listed. Using the properly sized
wrought iron, approved flexible or steel pipe, make gas con-
nections to the unit. Installation of a drop leg and ground
union is required. Refer to Figure 7.
ELECTRICAL POWER CONNECTION
Field wiring to the unit must conform to and be grounded in
accordance with the provisions of the National Electrical
Code ANSI/NFPA No. 70 latest edition, Canadian Electric
Code C22.1 Part 1 (latest edition) and/or local codes. Electri-
cal wires which are field installed shall conform with the tem-
perature limitation for 63F/35C rise wire when installed in
accordance with instructions. Specific electrical data is given
on the furnace rating plate.
Provide a power supply separate from all other circuits. Install
overcurrent protection and disconnect switch per local/
national electrical codes. The switch should be reasonably
close to the unit for convenience in servicing. With the dis-
connect switch in the OFF position, check all wiring against
the unit wiring label. Also, see the wiring diagram in this
instruction.
An overpressure protection device, such as a pres-
sure regulator, which conforms to the National Fuel
Gas Code, ANSI Z223.1 (U.S.) or CANB149.1 or .2
(Canada) and acts to limit the downstream pressure
to value that does not exceed 0.5 PSI (14" w.c.),
must be installed in the gas piping system upstream
of the furnace. Failure to do so may result in a fire or
explosion or cause damage to the furnace or some
of its components.
Never apply a pipe wrench to the body of the combi-
nation automatic gas valve. A wrench must be
placed on the projection or wrench boss of the valve
when installing piping to it.
INLET GAS PRESSURE RANGE
NATURAL GAS
PROPANE (LP)
Minimum
4.5 In. W.C.
11 In. W.C.
Maximum
13.8 In. W.C.
13.8 In. W.C.
FIGURE 7 :
Gas Piping
Compounds used on threaded joints of gas piping
must be resistant to the action of liquefied petroleum
gases.
NOTE:
1/8” NPT plug is included in the inlet side of
the gas valve for measuring incoming gas pressure.
After all gas piping connections are completed, leak
test all joints, fittings and furnace connections with
rich soap and water solution, commercial available
bubble type leak detection fluid, or other approved
means.
Do not use an open flame or other source of ignition
for leak testing.
GAS VALVE
TO GAS
SUPPLY
EXTERNAL MANUAL
SHUTOFF VALVE
TO GAS
SUPPLY
DROP LEG
GROUND JOINT UNION
MAY BE INSTALLED
INSIDE OR OUTSIDE UNIT
