The furnace must have a 115-v power supply properly connected
and grounded. Proper polarity must be maintained for correct
operation. Thermostat wire connections at R, W, C, and Y must be
made at the 24-v terminal block on the control board. The gas
service pressure must not exceed 0.5 psig (14-in. wc), but must be
no less than 0.16 psig (4.5-in. wc).
Before operating the furnace, check each manual reset switch for
continuity. If necessary, press the button to reset the switch.
The blower compartment door must be in place to complete the
115-v circuit to the furnace.
→
Fig. 12—Heating and Cooling Application Wiring Diagram
A95241
115-VOLT FIELD-
SUPPLIED
FUSED
DISCONNECT
AUXILIARY
J-BOX
CONTROL
BOX
24-VOLT
TERMINAL
BLOCK
THREE-WIRE
HEATING-
ONLY
FIVE
WIRE
NOTE 1
NOTE 2
FIELD-SUPPLIED
FUSED DISCONNECT
CONDENSING
UNIT
TWO
WIRE
FURNACE
R
G
C
W
C
R
G
Y
GND
GND
FIELD 24-VOLT WIRING
FIELD 115-, 208/230-, 460-VOLT WIRING
FACTORY 24-VOLT WIRING
FACTORY 115-VOLT WIRING
208/230- OR
460-VOLT
THREE
PHASE
208/230-
VOLT
SINGLE
PHASE
WHT
BLK
WHT
BLK
NOTES:
Connect Y-terminal as shown for proper operation.
Some thermostats require a "C" terminal connection as shown.
If any of the original wire, as supplied, must be replaced, use
same type or equivalent wire.
W
Y
GND
THERMOSTAT
TERMINALS
1.
2.
3.
→
Fig. 11—Control Board
A95086
C
OM
24V
HUM
G
R
Y
W
3-AMP FUSE
HUMIDIFIER TERMINAL
(24-VAC 0.5 AMP MAX)
LED OPERATION &
DIAGNOSTIC LIGHT
HARNESS CONNECTOR
24-V TRANSFORMER SEC-2
SPARE-1
SPARE-2
EAC-1
EAC-ELECTRONIC AIR CLEANER
TERMINALS (115-VAC 1.5 AMP MAX)
EAC-2
115-VAC (L2) NEUTRAL
CONNECTION
24-V THERMOSTAT
TERMINALS
BLOWER SPEED
SELECTION TERMINALS
INDUCER MOTOR
CONNECTOR
115-VAC (L1)
POWER SUPPLY
HOT SURFACE
IGNITOR CONNECTOR
HEAT
COOL
SEC-1
TEST/TWIN
—9—
