356485-UIM-G-1211
12
Johnson Controls Unitary Products
SECTION V: ELECTRICAL POWER
ELECTRICAL POWER CONNECTIONS
Field wiring to the unit must be grounded. Electric wires that are field
installed shall conform to the temperature limitation for 63°F (35°C) rise
wire when installed in accordance with instructions. Refer to Table 6 in
these instructions for specific furnace electrical data.
Annual Fuel Utilization Efficiency (AFUE) numbers are determined in accordance with DOE Test procedures.
Wire size and over current protection must comply with the National Electrical Code (NFPA-70-latest edition) and all local codes.
The furnace shall be installed so that the electrical components are protected from water.
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” (10.2 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 Figures 17 or 18. 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.
Use copper conductors only.
Table 6:
Ratings & Physical / Electrical Data
Input
Output
Nominal
Airflow
AFU
E
Air Temp.
Rise
Max.
Outlet
Air Temp
Blower
Blower
Size
Max
Over-Current
Protect
Total
Unit
Amps
Min. wire Size
(awg) @ 75 ft
one way
MB
H
kW
MB
H
kW
CFM
m
3
/
min
°F
°C
°F
°C
HP
Amp
s
40
11.7
32
9.4
800
22.7
80.0
25-55
14-31
155
68.3
1/5
2.1
9 x 8
10
4.5
14
60
17.6
48
14.1
1000
28.3
80.0
25-55
14-31
155
68.3
1/3
3.8
9 x 8
10
6.0
14
60
17.6
48
14.1
1200
34.0
80.0
30-60
17-33
170
76.7
1/3
4.8
11 x 8
10
7.0
14
80
23.5
64
18.8
1200
34.0
80.0
35-65
19-36
165
73.9
1/3
4.8
11 x 8
10
7.5
14
80
23.5
64
18.8
1600
45.3
80.0
25-55
14-31
155
68.3
1/2
7.5
11 x 10
15
10.0
14
80
23.5
64
18.8
2200
62.3
80.0
25-55
14-31
155
68.3
1
14.5
11 x 11
20
16.0
12
100
29.3
80
23.4
1200
34.0
80.0
40-70
22-39
170
76.7
1/3
4.8
9 x 8
10
7.5
14
100
29.3
80
23.4
1600
45.3
80.0
35-65
19-36
165
73.9
1/2
7.5
11 x 10
15
10.0
14
100
29.3
80
23.4
2000
56.6
80.0
25-55
14-31
155
68.3
1
14.5
11 x 11
20
17.0
12
120
33.7
96
26.9
1600
45.3
80.0
40-70
22-39
170
76.7
1/2
7.5
11 x 10
15
10.0
14
120
33.7
96
26.9
2000
56.6
80.0
30-60
17-33
160
71.1
1
14.5
11 x 11
20
17.0
12
130
38.1
104
30.5
2000
56.6
80.0
35-65
19-36
165
73.9
1
14.5
11 x 11
20
17.0
12
FIGURE 16:
Electrical Wiring
Electrical Entry
Junction
Box
L1-Hot
Neutral
Connect ground
lead to screw
BLK
WHT
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.
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.
