5532522-UIM-B-0619
Johnson Controls Ducted Systems
9
SUPPLY VOLTAGE CONNECTIONS
1. Provide a power supply separate from all other circuits. Install over-
current protection and disconnect switch per local/national electrical
codes. The switch should be close to the unit for convenience in
servicing. With the disconnect or fused switch in the OFF position,
check all wiring against the unit wiring label. Refer to the wiring dia-
gram 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 junction box,
there are two wires, a black wire and 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 section.
The black furnace lead must be connected to the L1 (hot) wire from
the power supply. The white furnace screw must be connected to
neutral. Connect the power supply ground to the green screw
(equipment ground) An alternate wiring method is to use a field pro-
vided 2” (5.1 cm) x 4” (10.1 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 connections replace the wiring box cover and
screws. Refer to Figure 10.
3. The furnace's control system requires correct polarity of the power
supply and a proper ground connection. Refer to Figure 10.
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 low voltage
terminal block on the integrated furnace control board, as shown in Fig-
ures 11 and 12. Electronic thermostats require the common wire to be
connected. Apply strain relief to thermostat wires passing through cabi-
net. 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 outdoor unit.
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 a
split system air conditioner or heat pump.
FIGURE 10:
Electrical Wiring
JUNCTION
BOX
ELECTRICAL
ENTRY
CONNECT
GROUND
LEAD TO
SCREW
A1093-001
IMPORTANT:
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 fur-
nace and fasten using holes provided.
IMPORTANT:
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.
IMPORTANT:
Some electronic thermostats do not have adjustable
heat anticipators. They should be set to six cycles per hour. Follow
the thermostat manufacturer's instructions.
FIGURE 11:
Thermostat Chart - Single Stage AC with Single Stage Furnaces
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