271001-UIM-A-0407
Unitary Products Group
11
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, Figure 28, in this instruction.
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 wiring
label on the inside of the blower compartment door or Figure 8.
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” (5.1 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.
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
DIAGNOSTICS" section of the “User’s Information, Maintenance,
& Service Manual” provided with this furnace for symptoms of
reversed power supply polarity.
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 9 & 10. Electronic
thermostats may require the common wire to be connected as shown in
Figures 9 & 10. 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 control board to the
proper wires on the condensing unit (unit outside).
IMPORTANT:
Some electronic thermostats do not have adjustable
heat anticipators. They may have other type cycle rate adjustments.
Follow the thermostat 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.
For additional connection diagrams for all UPG equipment refer to “Low
Voltage System Wiring” document available online at www.upgnet.com
in the Product Catalog Section.
FIGURE 8:
Electrical Wiring
BLK/BLK
WHT/WHT
GRN/GRN
HUM
EAC
L1
(HOT)
N
GND
HUM (HOT)
EAC (HOT)
GRN
WHT
BLK
JUNCTION
BOX
DOOR SWITCH
CLASS 2 SYSTEM
CONTROL WIRING
TO THERMOSTAT
WIRING INSIDE
JUNCTION BOX
BURNER
COMPARTMENT
BLOWER
COMPARTMENT
IGNITION
MODULE
Set the heat anticipator in the room thermostat as shown below. Set-
ting it lower will cause short cycles. Setting it higher will cause the
room temperature to exceed the setpoint.
Two-Stage Thermostat
First Stage
.4 Amps
Second Stage
.6 Amps
Single Stage Thermostat
.4 Amps
Do not exceed 1.0 amp loading.
