035-19656-003 Rev. A (1004)
10
Unitary Products Group
SUPPLY VOLTAGE CONNECTIONS
1.
Provide a power supply separate from all other circuits. Install
overcurrent protection and disconnect switch per local/national
electrical codes. The switch should be close to the unit for conve-
nience in servicing. With the disconnect or fused switch in the OFF
position, check all wiring against the unit wiring label. Refer to the
wiring diagram in this instruction.
2.
Remove the screws retaining the wiring box cover. Route the
power wiring through the opening in the unit into the junction box
with a conduit connector or other proper connection. In the junc-
tion box there will be three wires, a Black Wire, a White Wire and a
Green Wire. Connect the power supply as shown on the unit-wir-
ing label on the inside of the blower compartment door or the wir-
ing schematic in this section. The black furnace lead must be
connected to the L1 (hot) wire from the power supply. The white
furnace lead must be connected to neutral. Connect the green fur-
nace lead (equipment ground) to the power supply ground. An
alternate wiring method is to use a field provided 2” (5.1 cm) x 4”
(10.2 cm) box and cover on the outside of the furnace. Route the
furnace leads into the box using a protective bushing where the
wires pass through the furnace panel. After making the wiring con-
nections replace the wiring box cover and screws. Refer to Figure
11.
3.
The furnace's control system requires correct polarity of the power
supply and a proper ground connection. Refer to Figure 12.
IMPORTANT:
The power connection leads and wiring box may be relo-
cated to the left side of the furnace. Remove the screws and cut wire tie
holding excess wiring. Reposition on the left side of the furnace and fas-
ten using holes provided.
LOW VOLTAGE CONTROL WIRING CONNECTIONS
Install the field-supplied thermostat by following the instructions that
come with the thermostat. With the thermostat set in the OFF position
and the main electrical source disconnected, connect the thermostat
wiring from the wiring connections on the thermostat to the terminal
board on the ignition module, as shown in Figures 13 or 14. Electronic
thermostats may require the common wire to be connected as shown
with the dashed line in Figures 13 or 14. Apply strain relief to thermostat
wires passing through cabinet. If air conditioning equipment is installed,
use thermostat wiring to connect the Y and C terminals on the furnace
control board to the proper wires on the condensing unit (unit outside).
Refer to Figure 13. For two-stage condensing units, connect the Y1, Y2
and C terminals on the furnace control to the proper wires on the out-
side unit. See Figure 14.
IMPORTANT:
Set the heat anticipator in the room thermostat to 0.10
amps. Setting it lower will cause short cycles. Setting it higher will cause
the room temperature to exceed the set points.
IMPORTANT:
Some electronic thermostats do not have adjustable heat
anticipators. They may have other type cycle rate adjustments. Follow
the thermostat manufacturer's instructions.
The 24-volt, 40 VA transformer is sized for the furnace components
only, and should not be connected to power auxiliary devices such as
humidifiers, air cleaners, etc. The transformer may provide power for an
air conditioning unit contactor.
ACCESSORY CONNECTIONS
The furnace control will allow power-switching control of various acces-
sories. Refer to Figure 15, for connection details.
ELECTRONIC AIR CLEANER CONNECTION
Two 1/4” (6.4 mm) spade terminals (EAC and EAC N) for electronic air
cleaner connections are located on the control board. The terminals
provide 115 VAC (1.0 amp maximum) during circulating blower opera-
tion.
HUMIDIFIER CONNECTION
Two 1/4” (0.64 cm) spade terminals (HUM and HUM N) for humidifier
connections are located on the control board. The terminals provide 115
VAC (1.0 amp maximum) during heating system operation.
FIGURE 9:
Electrical Wiring
Y W RGC
CLASS 2 SYSTEM
CONTROL WIRING
TO THERMOSTAT
TRANSFORMER
IGNITION MODULE
BURNER COMPARTMENT
BLOWER COMPARTMENT
DOOR SWITCH
JUNCTION
BOX
BLK/BLK
WHT/WHT
GRN/GRN
L1
HOT
WHT
N
GND
GRN
BLK
FIGURE 10:
Line Wiring Connections
FIGURE 11:
Heating and Cooling Thermostat Connections
FIGURE 12:
Heating and Two-Stage Cooling Thermostat Connections
FIGURE 13:
Accessory Connections
BLK
WHT
GRN
BLK (HOT)
WHT (NEUTRAL)
GRN
NOMINAL
120 VOLT
ROOM
THERMOSTAT
FURNACE
CONTROL
CONDENSING
UNIT
TO AIR CONDITIONER
CONTROLS
R
W
G
Y
C
R
W
G
Y
C
COMMON T’STAT CONNECTION
ROOM
THERMOSTAT
FURNACE
CONTROL
CONDENSING
UNIT
TO AIR CONDITIONER
CONTROLS
R
W
G
Y1
C
R
W
G
C
COMMON T’STAT CONNECTION
Y2
Y1
Y2
115 VOLT
HUMIDIFER
115 VOLT
ELECTRONIC
AIR CLEANER
EAC HOT
HUM. HOT
BLK
WHT
EAC
HUM
NEUTRALS
SWITCHED
CIRCUITS
BLK
WHT
