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98618/035-20009-001
Rev. B (1205)
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 8 in
these instructions for specific furnace electrical data.
[& CAUTION
Use copper conductors
only.
TABLE 8: Ratings & Physical / Electrical Data - Upflow Models
Input
M7 . kW
22.0
Input
M7BH
kW
22.0
Output
MBH
kW
60
17.6
Max. Outlet
Air Temp
oF
oC
160
71.1
Nominal
CFM
cmm
1600
45.3
Blower
Hp
Amps
1/2
6.2
Cabinet Width
In.
cm
AFUE
°F
19 1/2
49.53
80.0
30-60
Air Temp. Rise
Blower
Total
Max
Size
Unit
Over-current
In.
cm
amps
protect
10x10
25.4 x 25.4
8.5
15
oC
16.7-33.3
Min. Wire Size
(awg) @ 75 ft.
one way
AWG
14
Operation
WGT.
LBS
143
Operation
WGT.
Kg
64.9
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-70-1atest 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 three wires (a Black Wire, a White Wire and
a Green 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 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.
3.
The furnace's control system requires correct polarity of the power
supply and a proper ground connection. Refer to Figure 10.
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 Figure 11. Electronic thermo-
stats may require the common wire to be connected as shown with the
dashed line in Figure 11. Apply strain relief to thermostat wires passing
through cabinet. If air conditioning
equipment
is installed,
use thermo-
stat wiring to connect
the Y and C terminals
on the furnace
control
board to the yellow and brown wires on the condensing
unit (unit out-
side). Refer to Figure 11.
Room
Furnace
Condensing
Thermostat
Control
Unit
_
To Air Conditioner
...................
..................
' moo T,stot ...................
BLK
A BLK (HOT)
WHT
AWHT (NEUTRAL)
f
GRN
NOMINAL
120 VOLT
FIGURE 11: Heating and Cooling Thermostat Connections
IMPORTANT:
Set the heat anticipator
in the room thermostat
to 0.45
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.
FIGURE 10: Line Wiring Connections
AWARNING
Check, the rating plate and power supply to be sure that the electri-
cal characteristics
match. All models
use nominal
1115 VAC, 1
Phase, 60Hz power supply.
Furnace shall be installed so the electrical
components
are pro-
tected from water.
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 12 for connection details.
10
Unitary Products Group
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