437642-UIM-C-0210
12
Johnson Controls Unitary Products
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 3 wires, a Black Wire, a White Wire. Connect
the power supply as shown on the unit-wiring label on the inside of
the blower compartment door or the wiring schematic in this sec-
tion. The black furnace lead must be connected to the L1 (hot)
wire from the power supply. The white furnace screw must be con-
nected to neutral. Connect the power supply ground to the green
screw (equipment ground) An alternate wiring method is to use a
field provided 2” (5.1 cm) x 4” (10.1 cm) box and cover on the out-
side 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 connections replace the wiring box
cover and screws. Refer to Figure 16.
3.
The furnace's control system requires correct polarity of the power
supply and a proper ground connection. Refer to Figure 16
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 Figure 18 or 19. Electronic
thermostats may require the common wire to be connected. Apply
strain relief to thermostat wires passing through cabinet. If air condition-
ing equipment is installed, use thermostat wiring to connect the Y and C
terminals on the furnace control board to the proper wires on the con-
densing unit (unit outside).
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.
ELECTRONIC AIR CLEANER CONNECTION
Two 1/4” (6.4 mm) spade terminals (EAC and NEUTRAL) for electronic
air cleaner connections are located on the control board. The terminals
provide 115VAC (1.0 Amp maximum) during circulating blower opera-
tion.
HUMIDIFIER CONNECTION
Two 1/4” (6.4 mm) spade terminals (HUM and NEUTRAL) for humidifier
connections are located on the control board. The terminals provide
115VAC (1.0 Amp maximum) during heating system operation.
A mounting hole is provided on the control panel next to the furnace
control board for mounting a humidifier transformer if required.
SECTION VI: VENT SYSTEM
VENT CONNECTIONS
All models are provided with a flue transition that is sized for 4” diame-
ter vent connections. If a larger size vent connector is required, that
connection must be installed external to the furnace. Figure 17 shows
the furnace as it is shipped from the factory. To convert to a horizontal
or downflow position, remove the four screws that secure the inducer
assembly and rotate 90° being careful not to damage the gasket. Rein-
stall screws. Remove cap from appropriate vent outlet location on the
cabinet, cut insulation in cabinet to same size as the hole provided and
reinstall cap in the hole in the top panel.
FIGURE 16:
Electrical Wiring
The power connection leads and wiring box may be relocated 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 fasten
using holes provided.
Set the heat anticipator in the room thermostat to 0.4 amps. Setting
it lower will cause short cycles. Setting it higher will cause the room
temperature to exceed the set points.
Electrical Entry
Junction
Box
L1-Hot
Neutral
Connect ground
lead to screw
BLK
WHT
Some electronic thermostats do not have adjustable heat anticipa-
tors. They should be set to six cycles per hour. Follow the thermo-
stat manufacturer's instructions.
In downflow applications, do not block the combustion air inlet. The
furnace must be installed on a coil cabinet or subbase to allow com-
bustion air to enter the burner compartment.
FIGURE 17:
Combustion Air Inducer
COMBUSTION AIR INDUCER
90°
90°
Mounting Screw
(Remove)
Flue Transition
(Do Not Remove)
Mounting Screw
(Remove)
Pressure
Switch
Pressure Switch
Tube Routing
