16
IO-247A
12/04
Thermostat Diagrams
S
ETTING
THE
H
EAT
A
NTICIPATOR
The following method should be used in measuring the amp
draw of the control circuit to assure proper adjustment of the
thermostat heat anticipator
R
R
• 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.
S
INGLE
-S
TAGE
T
HERMOSTAT
A
PPLICATION
A single-stage thermostat with only one heating stage can be used
to control this furnace. The application of a single-stage thermostat
does not offer “true” thermostat-driven two-stage operation, but
provides a
timed
transition from low to high fire. The furnace will
run on low stage for a fixed period of time before stepping up to
high stage to satisfy the thermostat’s call for heat. The delay
period prior to stepping up can be set at either 5 or 10 minutes
through the DIP switch adjacent to the Heat Off delay DIP switches
on the integrated control module. To use a single-stage thermostat,
turn off power to the furnace, move the thermostat selection jumper
on the integrated control module from the “two-stage” position to
the “single-stage” position, turn power back on. Refer to the
following figures.
3
2
1
T
W
O
S
I
N
G
L
E
TSTA T
OFF
3
2
1
T-S tat selection jumper in
single-stage thermostat
position.
DIP switch position 3: ON
Delay Period: 10 minutes.
DIP switch position 3: OFF
Delay Period: 5 minutes.
T
W
O
S
I
N
G
L
E
TSTAT
O N
24 V
OLT
D
EHUMIDISTAT
W
IRING
The optional usage of a dehumidistat allows the furnace’s circulator
blower to operate at a slightly lower speed during a combined
thermostat call for cooling and dehumidistat call for
dehumidification. This lower blower speed enhances
dehumidification of the conditioned air as it passes through the
AC coil. For proper function, a dehumidistat applied to this furnace
must operate on 24 VAC and utilize a switch which
opens on
humidity rise.
To install/connect a dehumidistat:
1. Turn OFF power to furnace.
2. Secure the dehumidistat neutral wire (typically the white
lead) to the screw terminal marked “DEHUM” on the furnace
integrated control module.
3. Secure the dehumidistat hot wire (typically the black lead)
to the screw terminal marked “R” on the furnace integrated
control module.
4. Secure the dehumidistat ground wire (typically the green
lead) to the ground screw on the furnace junction box.
NOTE:
Ground wire may not be present on all
dehumidistats.
5. Turn ON power to furnace.
To enable the dehumidify function on the integrated control module:
1. Cut the jumper wire labeled “CUT FOR DEHUM” located
adjacent to the DEHUM screw terminal.
Once the jumper wire is cut, the dehumidify function is enabled
during a
combination
call for cooling (T-Stat) and dehumidification
(Dehum-Stat). The yellow LED adjacent to the DEHUM screw
terminal will be illuminated during dehumidification.
0
YL0
Y
B/C
G
R
W1 W2
TWIN
DEHUM
CUT FOR
DEHUM
0
YL0
Y
B/C
G
R
W1 W2
CR35
R122
R128
W3
DS7
R19
1
R85
DS3
R84
R22
DS4
DS5
TP 1
TP 2
DEHUMIDIFICATION
LED (YELLOW)
DEHUMIDIFICATION
JUMPER WIRE
(CUT TO ENABLE)
W14
F
OSSIL
F
UEL
A
PPLICATIONS
This furnace can be used in conjunction with a heat pump in a
fossil fuel application. A fossil fuel application refers to a combined
gas furnace and heat pump installation which uses an outdoor
temperature sensor to determine the most cost efficient means of
heating (heat pump, gas furnace, or both).
A heat pump thermostat with
three stages of heat
is required
to properly use a two-stage furnace in conjunction with a heat
pump. Refer to the fossil fuel kit installation instructions for
additional thermostat requirements.
Strictly follow the wiring guidelines in the fossil fuel kit
installation instructions. All furnace connections must be
made to the furnace two-stage integrated control module and
the “FURNACE” terminal strip on the fossil fuel control board.
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.
