16
To ensure proper unit grounding, the ground wire should run from
the furnace ground screw located inside the furnace junction box
all the way back to the electrical panel.
NOTE:
Do not use gas
piping as an electrical ground. To confirm proper unit grounding,
turn off the electrical power and perform the following check.
1. Measure resistance between the neutral (white) connection
and one of the burners.
2. Resistance should measure 10 ohms or less.
This furnace is equipped with a blower door interlock switch which
interrupts unit voltage when the blower door is opened for servicing.
Do not defeat this switch.
24 V
OLT
T
HERMOSTAT
W
IRING
NOTE:
Wire routing must not interfere with circulator blower
operation, filter removal, or routine maintenance.
As a two-stage furnace, the furnace integrated control module
provides terminals for both “W1” and “W2”, and “YLO” and “Y”
thermostat connections. This allows the furnace to support the
following system applications: ‘Two-Stage Heating Only’, ‘Two-
Stage Heating with Single-Stage Cooling’, and ‘Two-Stage Heating
with Two-Stage Cooling’. Refer to the following figures and table
for proper connections to the integrated control module.
Low voltage connections can be made through either the right or
left side panel. Thermostat wiring entrance holes are located in
the blower compartment. The following figure shows connections
for a “heat only” system and “heat/cool system”.
This furnace is equipped with a 40 VA transformer to facilitate use
with most cooling equipment. Consult the wiring diagram, located
on the blower compartment door, for further details of 115 Volt
and 24 Volt wiring.
S
INGLE
S
TAGE
T
HERMOSTAT
A
PPLICATION
W
G
Y
Single-Stage Heating with Single-Stage Cooling
R
B/C
G
R
W1
W2
O
YLO
Y
DE HUM
TW IN
Y
C
NEU
HOT
Furnace Integrated
Control Module
Thermostat
Single-Stage Heating with
Single-Stage Cooling
(
)
Remote
Condensing Unit
(Single-Stage Cooling)
Dehumidistat
[Optional]
NOTE:
To apply a single-stage heating thermostat, the
thermostat selector jumper on the integrated Control
module
must
be set on single stage.
W1
G
Y
Two-Stage Heating with Single-Stage Cooling
R
W2
B/C
G
R
W1
W2
O
YLO
Y
DEHUM
TWIN
Y
C
NEU
HOT
Furnace Integrated
Control Module
Thermostat
Two-Stage Heating
with
Single-Stage Cooling
(
)
Remote
Condensing Unit
(Single-Stage Cooling)
Dehumidistat
[Optional]
G
Y
Two-Stage Heating with Two-Stage Cooling
R
B/C
G
R
W1
W2
O
YLO
Y
DEHUM
TWIN
NEU
HOT
Furnace Integrated
Control Module
Thermostat
Two-Stage Heating
with
Two-Stage Cooling
(
)
Remote
Condensing Unit
(Two-Stage Cooling)
Dehumidistat
[Optional]
Y
C
YLO
YLO
W2
W1
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
