16
IO-242
5/04
• Wrap the “R” leg around a clip-on amp meter 10 times.
• Energize the furnace in the heat mode.
• Record the reading.
• Divide this reading by 10.
• Set the heat anticipator on the thermostat to match this
reading.
Example: If the reading on the amp meter is “4”, divide this by 10.
The anticipator setting will be .4 amps.
115 V
OLT
L
INE
C
ONNECTION
OF
A
CCESSORIES
(H
UMIDIFIER
AND
E
LECTRONIC
A
IR
C
LEANER
)
WARNING
T
O AVOID PERSONAL INJURY, ELECTRICAL SHOCK OR DEATH, DISCONNECT
ELECTRICAL POWER BEFORE SERVICING OR CHANGING ANY ELECTRICAL
WIRING.
The furnace integrated control module is equipped with line voltage
accessory terminals for controlling power to an optional field-
supplied humidifier and/or electronic air cleaner.
The accessory load specifications are as follows:
Humidifier
1.0 Amp maximum at 120 VAC
Electronic Air Cleaner
1.0 Amp maximum at 120 VAC
Turn OFF power to the furnace before installing any accessories.
Follow the humidifier or air cleaner manufacturers’ instructions
for locating, mounting, grounding, and controlling these
accessories. Accessory wiring connections are to be made
through the 1/4" quick connect terminals provided on the furnace
integrated control module. The humidifier and electronic air
cleaner hot and neutral terminals are identified as HUM and EAC.
All field wiring must conform to applicable codes. Connections
should be made as shown in the following illustration.
EA
C
Li
ne
T
ran
sf
or
me
r
Hu
m
Li
ne
T
ran
sf
or
me
r
EA
C
Hu
m
Air Cleaner
Humidifier
Control Module
Hot 120 VAC
Neutral 120 VAC
Optional
Accessories
{
Figure 15 - 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
energized with 115 volts whenever the induced draft blower is
energized. The integrated control module electronic air cleaner
terminals (EAC) are energized with 115 volts whenever the
circulator blower is energized.
24 V
AC
H
UM
1. 24 VAC Hum - A ¼” piggy back quick connect terminal on
the pressure switch provides 24 VAC humidifier control.
this terminal will be powered any time the pressure switch
is closed. To connect 24 VAC hum, connect 24vac line of
humidifier to piggyback on the pressure switch. The com
side of the humidfier to C on the terminal strip on the control
board (or to com side to 24VAC transformer). Do not
connect 115V humidifier to these terminals.
T
WINNING
A twin terminal located on the thermostat terminal strip can be
used to twin two furnaces. This twin terminal synchronizes the
circulation blowers of the two furnaces. Furnaces must be same
model and heat / cool speeds the same. In addition, both furnaces
must be powered by separate circuits originating from the same
power leg in the main electrical box (hot and neutral
must
be in
phase). Furnaces can be twined to provide either single or 2-
stage heat. If used as 2-stage heat the temperature rise from the
register to return will be reduced during low fire operation.
To twin furnaces ensure models are the same, connect twin
terminals on both furnaces, ensure heat and cool speeds are the
same on both furnaces. For single stage operation connect twin
Y, G and W of both furnace control boards then wire thermostat
as normal to one of the furnaces. For 2-stage operation connect
Twin, Y and G of both furnaces connect on furnace to 2-stage
thermostat as normal connecting W1 on stat to W on this furnace
connect W2 to W on the second furnace. With 2-stage
configuration furnace 1 will provide low stage heat (circulator
blower of furnace 2 will run at heat speed). During a call for High
heat both furnaces will operate.
IX. GAS SUPPLY AND PIPING
G
ENERAL
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
appliances 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
NOTE:
Adjusting the minimum supply pressure below the limits
in the above table could lead to unreliable ignition. Gas input to
the burners must not exceed the rated input shown on the rating
plate. Overfiring of the furnace can result in premature heat
exchanger failure. Gas pressures in excess of 13 inches water
column can also cause permanent damage to the gas valve.
IMPORTANT NOTE:
The furnace will naturally derate itself with
altitude. Do not attempt to increase the firing rate by changing
orifices or increasing the manifold pressure. This can cause poor
combustion and equipment failure.
