SYSTEM OPERATION
7
The integrated control module electronic air cleaner terminals
(EAC) are energized with 115 volts whenever the circulator
blower is energized.
24 VOLT THERMOSTAT WIRING
NOTE:
Low voltage connections can be made through either
the right or left side panel. Wire routing must not interfere
with circulator blower operation, filter removal, or routine
maintenance.
A 40 V.A. transformer and an integrated electronic control
are built into the furnace to allow use with most cooling
equipment. Consult the wiring diagram located in this manual,
the installation manual, or on the blower door for further details
of 115 Volt and 24 Volt wiring.
Thermostat Wiring Diagrams
Y
C
Y
C
G
R
W
Y2
Y/Y1
C
G
R
W/W1
W2
ROOM THERMOSTAT
INTEGRATED FURNACE
CONTROL MODULE
REMOTE COOLING UNIT
(SINGLE STAGE)
Thermostat - Single -Stage Heating with Single-Stage Cooling
Thermostat - Single -Stage Heating with Single-Stage Cooling
NOTE:
To apply a single-stage Heating Thermostat, the staging option
must
be set on single-stage.
Y
C
Y
C
G
R
W/W1
Y2
Y/Y1
C
G
R
W/W1
W2
ROOM THERMOSTAT
INTEGRATED FURNACE
CONTROL MODULE
REMOTE COOLING UNIT
(SINGLE STAGE)
W2
Thermostat - Two-Stage Heating with Single-Stage Cooling
Y1
C
Y1
C
G
R
W1
Y2
Y/Y1
C
G
R
W/W1
W2
ROOM THERMOSTAT
INTEGRATED FURNACE
CONTROL MODULE
REMOTE COOLING UNIT
(TWO STAGE)
W2
Y2
Y2
Thermostat - Two-Stage Heating with Two-Stage Cooling
USING A SINGLE-STAGE HEATING THERMOSTAT
A single-stage heating thermostat may be used to control
this furnace; however, the furnace is setup by default to use
a two-stage heating thermostat. To use a single stage heat-
ing thermostat the installer must make the desired selec-
tions in the user menus using the push button switches on
the control board. When a single stage heating thermostat is
used there are two options for controlling the timed transition
from low to high fire: 1) Auto 2) Fixed Time.
•
Press the Left or Right menu switches to get to the
• A H S
menu.
•
The menu will display these options:
no 10 20 30 60 AUt
•
Fixed time options are expressed in minutes on the
display as:
10 20 30 60
.
•
If
AUt
(Automatic) is selected, the actual timing for the
transition to 2nd stage heat will be calculated by the
control board based on length of run time of previous
heating cycles (duty cycle).
•
Press the center switch to save the selection.
In Auto mode, the transition to 2nd stage heat will vary be-
tween 1 to 12 minutes.
Duty Cycle %
Heating Stage Timing
Demand
0-38
1
st
Stage, 12 minute 2
nd
Stage
Light
39-50
1
st
Stage, 10 minute 2
nd
Stage
Light to Average
51-62
1
st
Stage, 7 minute 2
nd
Stage
Average
63-75
1
st
Stage, 5 minute 2
nd
Stage
Average to Heavy
76-88
1
st
Stage, 3 minute 2
nd
Stage
Heavy
89-100
1
st
Stage, 1 minute 2
nd
Stage
Heavy
Using a Two Stage Heating Thermostat
•
The furnace is setup by default to use a two-stage
heating thermostat.
•
The menu may be accessed by pressing the Left or Right
menu switches to get to the
A H S
menu.
•
The menu will display these options:
no 10 20 30 60
AUt
.
•
Select
no
.
•
Press the center switch to save the selection.
•
In this mode only a W2 signal on the control board will
bring on 2nd stage heat.
Fossil Fuel Applications
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 or gas furnace).
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 instal-
lation 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.
