30
G
AS
S
UPPLY
AND
P
IPING
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 humidifier terminals (HUM) are en-
ergized with 115 volts whenever the induced draft blower is ener-
gized. The integrated control module electronic air cleaner termi-
nals (EAC) are energized with 115 volts whenever the circulator
blower is energized.
24 V
OLT
H
UMIDIFIER
A 5" long brown wire in the wire harness at the low fire pressure
switch provides 24 VAC humidifier control. This wire is powered
any time the pressure switch is closed. To connect 24 VAC HUM,
connect the 24 VAC line of the humidifier to the 5” brown wire. The
connection can be made by either stripping the wire and using a
wire nut or by using a field supplied quick connect terminal. The
wiring must conform to all local and national codes. Connect the
COM side of the humidifier to the C terminal on the furnace control
board (or to the COM side of the 24 VAC transformer). Do not
connect 115V humidifier to these terminals.
G
AS
S
UPPLY
AND
P
IPING
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.
CAUTION
T
O
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
.
Inlet gas supply pressures must be maintained within the ranges
specified in the following table. The supply pressure must be
constant and available with all other household gas fired appli-
ances operating. The minimum gas supply pressure must be
maintained to prevent unreliable ignition. The maximum must not
be exceeded to prevent unit overfiring.
Natural Gas
Minimum: 5.0" w.c.
Maximum:10.0" w.c.
Propane Gas
Minimum: 11.0" w.c.
Maximum:13.0" w.c.
Inlet Gas Supply Pressure
H
IGH
A
LTITUDE
D
ERATE
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 combus-
tion 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 alti-
tude 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.
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, flash-
back, 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 artifi-
cially derated, the appropriate orifice size must be determined
based upon the BTU/ft
3
content of the derated gas and the alti-
tude. 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 regard-
less of the BTU/ft
3
content of the fuel used. Contact your distribu-
tor for a tabular listing of appropriate altitude ranges and corre-
sponding manufacturer’s pressure switch kits.
P
ROPANE
G
AS
C
ONVERSION
WARNING
P
OSSIBLE
PROPERTY
DAMAGE
,
PERSONAL
INJURY
OR
DEATH
MAY
OCCUR
IF
THE
CORRECT
CONVERSION
KITS
ARE
NOT
INSTALLED
.
T
HE
APPROPRIATE
KITS
MUST
BE
APPLIED
TO
ENSURE
SAFE
AND
PROPER
FURNACE
OPERATION
.
A
LL
CONVERSIONS
MUST
BE
PERFORMED
BY
A
QUALIFIED
INSTALLER
OR
SERVICE
AGENCY
.
This unit is configured for natural gas. The appropriate
manufacturer’s propane gas conversion kit, must be applied for
propane gas installations. Refer to the
Propane Gas and/or High
Altitude Installations
for details.
