15
120 Volt Line Connections
Before proceeding with electrical connections, ensure that
the supply voltage, frequency, and phase correspond to
that specified on the unit rating plate. Power supply to the
furnace must be NEC Class 1, and must comply with all ap-
plicable codes. The furnace must be electrically grounded
in accordance with local codes or, in their absence, with the
atest edition of The National Electric Code, ANSI NFPA 70.
Use a separate fused branch electrical circuit containing
properly sized wire, and fuse or circuit breaker. The fuse
or circuit breaker must be sized in accordance with the
maximum overcurrent protection specified on the unit rating
plate. An electrical disconnect must be provided at the
furnace location.
Line voltage wiring
must enter into the junction box provided
with the furnace.
Line polarity must be observed when making field connections.
Line voltage connections can be made through either the right
or left side panel. To relocate the junction box, follow the steps
shown in the Junction Box Relocation section.
Junction Box Relocation
E
DGES
OF
SHEET
METAL
HOLES
MAY
BE
SHARP
. U
SE
GLOVES
AS
A
PRECAUTION
WHEN
REMOVING
HOLE
PLUGS
.
WARNING
Line voltage connections can be made through either the
right or left side panel. The furnace is shipped configured
for a right side electrical connection. To make electrical
connections through the opposite side of the furnace, the
junction box must be relocated to the left side prior to making
electrical connections. To relocate the junction box, perform
the following steps.
T
O
PREVENT
PERSONAL
INJURY
OR
DEATH
DUE
TO
ELECTRIC
SHOCK
,
DISCONNECT
ELECTRICAL
POWER
BEFORE
INSTALLING
OR
SERVICING
THIS
UNIT
.
WARNING
1. Remove both doors from the furnace.
2. Remove and save the screws holding the junc tion box
to the right side of the furnace.
3. Models that have the junction box located in the burner
compartment will need to move the junction box directly
over.
4. Attach the junction box to the left side of the fur nace,
using the screws removed in step 2.
5. Check the location of the wiring. Confirm that it will
not be damaged by heat from the burners or by the
rotation of the fan. Also confirm that wiring location will
not interfere with fil ter removal or other maintenance.
After the junction box is in the desired location, use washers
to connect field-supplied conduit to the junction box in accor
-
dance with NEC and local codes. Connect hot, neutral, and
ground wires as shown in the furnace wiring diagram. The
wires and ground screw are located in the furnace junction box.
Low voltage wires may be connected to the terminal strip.
IMPORTANT NOTE:
To avoid possible equipment malfunc-
tion, route the low voltage wires to avoid interference with filter
removal or other maintenance.
HIGH VOLTAGE
!
T
O
AVOID
THE
RISK
OF
INJURY
,
ELECTRICAL
SHOCK
OR
DEATH
,
THE
FURNACE
MUST
BE
ELECTRICALLY
GROUNDED
IN
ACCORDANCE
WITH
LOCAL
CODES
OR
IN
THEIR
ABSENCE
,
WITH
THE
LATEST
EDITION
OF
THE
N
ATIONAL
E
LECTRIC
C
ODE
.
WARNING
To ensure proper unit grounding, the ground wire should run
from the furnace ground screw located inside the furnace
junction box all the way back to the electrical panel.
NOTE:
Do not use gas piping as an electrical ground. To confirm
proper unit grounding, turn off the electrical power and perform
the following check.
1. Measure resistance between the neutral (white)
connection and the unpainted surface on the furnace.
2. Resistance should measure 10 ohms or less.
This furnace is equipped with a blower door interlock switch
which interrupts unit voltage when the blower door is opened
for servicing. Do not defeat this switch.
24 Volt Thermostat Wiring
NOTE:
Wire routing must not interfere with circulator blower
operation, filter removal, or routine maintenance.
Low voltage connections can be made through either the right
or left side panel. Thermostat wiring entrance holes are locat-
ed in the blower compartment. The following figure shows
connections for a “heat only” system and “heat/cool system”.
Furnace
Control
Furnace
Control
Remote
Condensing
Unit
Heating
Room
Thermostat
Heating/Cooling
Room Thermostat
W
W
Typical Field Wiring (24 VAC Control Circuit)
Figure 9
This furnace is equipped with a 40 VA transformer to facilitate
use with most cooling equipment. Consult the wiring diagram,
located on the blower compartment door, for further details of
120 Volt and 24 Volt wiring.
A single-stage thermostat with only one heating stage is
needed to control this furnace.
