Gas Piping; Gas Valve - Johnson Controls TM8E Installation Manual

SIDE RETURN
Locate the "L" shaped corner locators. These indicate the size of the cut-
out to be made in the furnace side panel. Refer to Figure 8.
FIGURE 8: Side Return Cutout Markings
Install the side filter rack following the instructions provided with that
accessory. If a filter(s) is provided at another location in the return air
system, the ductwork may be directly attached to the furnace side
panel.
IMPORTANT: Some accessories such as electronic air cleaners and
pleated media may require a larger side opening. Follow the instruc-
tions supplied with that accessory for side opening requirements. Do
not cut the opening larger than the dimensions shown in Figure 7.
HORIZONTAL FILTERS
Any branch duct (rectangular or round duct) attached to the plenum
must attach to the vertical plenum before the filter. Use of straps and/or
supports is required to support the weight of the external filter box.
DOWNFLOW FILTERS
CAUTION
!
In downflow furnace arrangement, the filter must be located a mini-
mum of 12" from the return air inlet of furnace.
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.
To Gas
External
Supply
Manual
Shut-off
Valve
Ground
Union
Drip
Leg
Upflow
Configuration
FIGURE 10: Gas Piping
Johnson Controls Ducted Systems
NOTE: Ground Union maybe installed inside or outside unit.
To Gas
External
To Gas
Supply
Manual
Supply
Shut-off
Valve
Ground
Union
Gas
Pipe
Gas
Valve
Drip
Leg
Drip
Leg
Downflow
Configuration
SECTION IV: GAS PIPING
GAS SAFETY
DANGER
!
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 PSI (14" w.c., 3.48 kPa). Pressures exceeding
0.5 PSI (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 fur-
nace or some of its components that will result in property damage
and loss of life.
OUTLET
PRESSURE
PORT
INLET
WRENCH
BOSS
INLET
PRESSURE
ON/OFF SWITCH
PORT
(Shown in ON position)
FIGURE 9: Gas Valve
IMPORTANT: Plan your gas supply before determining the correct
gas pipe entry. Use 90-degree service elbow(s), or short nipples and
conventional 90-degree elbow(s) to enter through the cabinet access
holes.
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 furnace
rating plate and the instructions in this section specify the type of gas
approved for this furnace - only use those approved gases. The instal-
lation of a drip leg and ground union is required. Refer to Figure 10.
To Gas
Supply
Gas
Valve
Ground
Union
Gas
Valve
Drip
Leg
Gas Pipe
Horizontal
Configuration
5594752-UIM-C-1119
VENT PORT
OUTLET
MAIN REGULATOR
ADJUSTMENT
Ground
Union
To Gas
Supply
Drip Leg
External
Manual
Shut-off
Valve
To Gas
Supply
Ground
Union
Drip Leg
A0226-001
9