292278-UIM-A-0108
8
Unitary Products Group
SECTION VI: ELECTRICAL POWER
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.
ELECTRICAL POWER CONNECTIONS
All models use nominal 115 VAC, 1 Phase, 60-Hertz power supply. DO
NOT CONNECT THIS APPLIANCE TO A 50 HZ POWER SUPPLY OR
A VOLTAGE ABOVE 130 VOLTS.
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 5 in
these instructions for specific furnace electrical data.
SUPPLY VOLTAGE CONNECTIONS
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.
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 shown in Figure 26.
2.
Remove the screws retaining the junction 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 Figure 4.
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 furnace lead (equipment ground) to
the power supply ground. An alternate wiring method is to use a
field provided 2” (5.08 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 connections replace the wiring box
cover and screws.
3.
The furnace's control system requires correct polarity of the power
supply and a proper ground connection. If the power supply polar-
ity is reversed, the control board will flash 9 times. The furnace will
not operate until the polarity is corrected. Refer to “Furnace Diag-
nostics” section of the “User’s Information, Maintenance, & Ser-
vice Manual provided with this furnace.
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
strip on the furnace control board, as shown in Figures 5-9. Electronic
thermostats may require the common wire to be connected to the "C"
terminal as shown in Figures 5-9. 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 con-
trol board to the condensing unit (unit outside) as shown in Figures 5-9.
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 should be set to six cycles per hour. Follow the ther-
mostat 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.
TABLE 5:
Electrical and Performance Data
Input
Max/Min
Output Max/Min
Blower Size
Blower
Max.
Over-current
Protect
Air Temp. Rise
Maximum Input
Air Temp. Rise
Minimum Input
MBH
kW
MBH
kW
In.
cm
HP
Amps
°F
°C
°F
°C
60/21
18/6
57/20
17/6
11 x 8
27.9 x 20.3
1/2
7.7
20
40 - 70
22 - 39
20 - 50
11 - 28
80/28
23/8
76/26
22/8
11 x 8
27.9 x 20.3
1/2
7.7
20
40 - 70
22 - 39
20 - 50
11 - 28
80/28
23/8
76/26
22/8
11 x 10
27.9 x 25.4
3/4
9.6
20
40 - 70
22 - 39
20 - 50
11 - 28
100/35
29/10
95/33
28/10
11 x 10
27.9 x 25.4
3/4
9.6
20
40 - 70
22 - 39
20 - 50
11 - 28
100/35
29/10
95/33
28/10
11 x 11
27.9 x 27.9
1
12.8
20
40 - 70
22 - 39
20 - 50
11 - 28
120/42
35/12
115/39
34/11
11 x 11
27.9 x 27.9
1
12.8
20
40 - 70
22 - 39
20 - 50
11 - 28
Max. Outlet
Air Temp.
Nominal Airflow
Cabinet Width
Total
Unit
AFUE
Min. Wire Size
(awg) @ 75 ft.
One Way
Approximate
Operating Weight
Power Supply
(Voltage-PH-Hz)
°F
°C
CFM
m
3
/min
In.
cm
Amps
%
170
76.7
1200
34.0
17-1/2
44.4
9
95.0
14
135
115-1-60
170
76.7
1200
34.0
17-1/2
44.4
9
95.0
14
142
115-1-60
170
76.7
1600
45.3
21
53.3
12
95.0
14
157
115-1-60
170
76.7
1600
45.3
21
53.3
12
95.0
14
162
115-1-60
170
76.7
2000
56.6
21
53.3
14
95.0
12
164
115-1-60
170
76.7
2000
56.6
24-1/2
62.2
14
95.0
12
180
115-1-60
Use copper conductors only.
FIGURE 4:
Electrical Wiring
N
GND
L1
HOT
WHT
GRN
BLK
BLK/BLK
WHT/WHT
GRN/GRN
CLASS 2 SYSTEM
CONTROL WIRING
TO THERMOSTAT
BLOWER
COMPARTMENT
DOOR SWITCH
TRANSFORMER
CONTROL
BOARD
115 VAC
