26
Optional Accessories Wiring
If it is necessary for the installer to supply additional line voltage
wiring to the inside of the furnace, the wiring must conform to all
local codes, and have a minimum temperature rating of 105°C.
All line voltage wire splices must be made inside the furnace
junction box.
The integrated control module electronic air cleaner terminals
(EAC) are energized with 115 volts whenever the circulator blower
is energized.
24-Volt Humidifier
The yellow wire connected to the induced draft blower pressure
switch is powered anytime the pressure switch is closed and
provides 24 VAC humidifier control.
1. Remove the yellow wire and connect the supplied brown
jumper wire to the pressure switch terminal.
2. Reconnect the yellow wire to the “piggyback” terminal on the
brown jumper.
3. Connect the 24 VAC line of the humidifier to the stripped end
of the brown wire.
NOTES:
■
Using a wire connector or a field-supplied quick connect
terminal can make this connection.
■
The wiring must conform to all local and national codes.
4. Connect the COM side of the humidifier to the B/C terminal
on the furnace control board (or to the COM side of the
24 VAC transformer).
NOTE: Do not connect 115-volt humidifier to these terminals.
GAS SUPPLY AND PIPING
The furnace rating plate includes the approved furnace gas input
rating and gas types. The furnace must be equipped to operate
on the type of gas applied. This includes any conversion kits
required for alternate fuels and/or high altitude.
Inlet gas supply pressures must be maintained within the ranges
specified in the Inlet Gas Supply Pressure chart. The supply
pressure must be constant and available with all other household
gas-fired appliances operating. The minimum gas supply pressure
must be maintained to avoid unreliable ignition. The maximum
must not be exceeded to keep the furnace from overfiring.
High Altitude Derate
When this furnace is installed at high altitude, the appropriate
high altitude orifice kit must be applied. This is required due to
the natural reduction in the density of both the gas fuel and
combustion air as altitude increases. The kit will provide the
proper design-certified input rate within the specified altitude
range.
High altitude kits are purchased according to the installation
altitude and usage of either Natural or propane gas. Contact your
distributor for a tabular listing of appropriate altitude ranges and
corresponding manufacturer’s high altitude (Natural, propane
gas, and/or pressure switch) kits.
NOTE: Do not derate the furnace by adjusting the manifold
pressure to a lower pressure than specified on the furnace rating
plate. The combination of the lower air density and a lower
manifold pressure will prohibit the burner orifice from drawing the
proper amount of air into the burner. This may cause incomplete
combustion, flashback and possible yellow tipping.
In some areas the gas supplier may artificially derate the gas in
an effort to compensate for the effects of altitude. If the gas is
artificially derated, the appropriate orifice size must be
determined based upon the Btu/ft
3
content of the derated gas
and the altitude. Refer to the National Fuel Gas Code, NFPA 54/
ANSI Z223.1, and information provided by the gas supplier to
determine the proper orifice size.
A different pressure switch may be required at high altitude
regardless of the Btu/ft
3
content of the fuel used. Contact your
distributor for a tabular listing of appropriate altitude ranges and
corresponding manufacturer’s pressure switch kits.
Propane Gas Conversion
This furnace is configured for Natural gas. The appropriate
manufacturer’s propane gas conversion kit, must be applied for
propane gas installations. See “Propane Gas and/or High Altitude
Installations.”
12-Pin Connector
Integrated
Control
Module
Electronic
Air Cleaner
EAC-H
120 VAC Hot and
Park Terminals
120 VAC
Neutral Terminals
Inlet Gas Supply Pressure
Natural gas
5.0" W.C. minimum; 10.0" W.C. maximum
Propane gas
11.0" W.C. minimum; 13.0" W.C. maximum
To prevent unreliable operation or equipment damage,
the inlet gas supply pressure must be as specified on the
unit rating plate with all other household gas-fired
appliances operating.
CAUTION
Placeholder
Possible property damage, personal injury or death may
occur if the correct conversion kits are not installed. The
appropriate kits must be applied to ensure safe and proper
furnace operation. All conversions must be performed by
a qualified installer or service agency.
WARNING
