035-14527-000 REV A (599)
Form 650.77-N3U
Unitary Products Group
13
SUPPLY AIR DUCTS
Installations on combustible material or floors must use a
combustible floor base (Refer to Figure 9 on page13)
(1CB0314, 17, 21 & 24) as specified on the rating plate or a
matching cooling coil. Follow the instructions supplied with
the combustible floor base accessory.
This base can be replaced with a matching cooling coil, prop-
erly sealed to prevent leaks. Follow the cooling coil instruc-
tions on page23 for installing the plenum.
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-
FIGURE 8 : DOWNFLOW FILTERS
FIGURE 9 : COMBUSTIBLE FLOOR BASE
ACCESS’Y
An overpressure protection device, such as a
pressure regulator, which conforms to the National
Fuel Gas Code, ANSI Z223.1 (U.S.) or CAN-
B149.1 or.2 (Canada) and acts to limit the down-
stream 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 com-
bination automatic gas valve. A wrench must be
placed on the projection or wrench boss of the
valve when installing piping to it.
