York CP9C Series Installation Manual Download

Page: 10 / 46

1083292-UIM-A-0114

Johnson Controls Unitary Products

Horizontal Filters

Any branch duct (rectangular or round duct) attached to the plenum
must attach to the vertical plenum before the filter. The use of straps
and/or supports is required to support the weight of the external filter
box.

Downflow Filters

Downflow furnaces typically are installed with the filters located above
the furnace, extending into the return air plenum or duct. Any branch
duct (rectangular or round duct) attached to the plenum must attach to
the vertical plenum above the filter height.

Filter(s) may be located in the duct system external to the furnace using
an external duct filter box attached to the furnace plenum or at the end
of the duct in a return filter grille(s). The use of straps and/or supports is
required to support the weight of the external filter box.

SECTION IV: GAS PIPING

GAS SAFETY

GAS PIPING INSTALLATION

Properly sized wrought iron, approved flexible or steel pipe must be
used when making gas connections to the unit. If local codes allow the
use of a flexible gas appliance connection, always use a new listed con-
nector. Do not use a connector that has previously serviced another gas
appliance.

Some utility companies or local codes require pipe sizes larger than the
minimum sizes listed in these instructions and in the codes. The fur-
nace rating plate and the instructions in this section specify the type of
gas approved for this furnace - only use those approved gases. The
installation of a drip leg and ground union is required. Refer to Figure
16.

The furnace must be isolated from the gas supply piping system by
closing its individual external manual shutoff valve during any pressure
testing of the gas supply piping system at pressures equal to or less
than 0.5 psig (3.5 kPa).

Gas piping may be connected from either side of the furnace using any
of the gas pipe entry knockouts on both sides of the furnace. Refer to
Figures 13 and 16.

All filters and mounting provision must be field supplied. All installa-
tions must have a filter installed.

An overpressure protection device, such as a pressure regulator,
must be installed in the gas piping system upstream of the furnace
and must act to limit the downstream pressure to the gas valve so it
does not exceed 0.5 psig [14" w.c. (3.48 kPa)]. Pressures exceed-
ing 0.5 psig [14” w.c. (3.48 kPa)] at the gas valve will cause damage
to the gas valve, resulting in a fire or explosion or cause damage to
the furnace or some of its components that will result in property
damage and loss of life.

Plan your gas supply before determining the correct gas pipe entry.
Use 90° service elbow(s), or short nipples and conventional 90°
elbow(s) to enter through the cabinet access holes.

FIGURE 15:

Gas Valve

An accessible manual shutoff valve must be installed upstream of
the furnace gas controls and within 6 feet (1.8 m) of the furnace.

The gas valve body is a very thin casting that cannot take any
external pressure. Never apply a pipe wrench to the body of the gas
valve when installing piping. A wrench must be placed on the octa-
gon hub located on the gas inlet side of the valve. Placing a wrench
to the body of the gas valve will damage the valve causing improper
operation and/or the valve to leak.

Inlet
Pressure
Tap

Outlet
Pressure
Tap

On/Off
Switch

Main
Regulator
Adjustment

FIGURE 16:

Gas Piping

Upflow

Configuration

Downflow

Configuration

Horizontal

Configuration