17
W
IRING
H
ARNESS
The wiring harness is an integral part of this furnace. Field
alteration to comply with electrical codes should not be re-
quired. Wires are color coded for identification purposes. Re-
fer to the wiring diagram for wire routings. If any of the original
wire as supplied with the furnace must be replaced, it must be
replaced with wiring material having a temperature rating of at
least 105° C. Any replacement wiring must be a copper con-
ductor.
115 V
OLT
L
INE
C
ONNECTIONS
Before proceeding with electrical connections, ensure that the
supply voltage, frequency, and phase correspond to that speci-
fied on the unit rating plate. Power supply to the furnace must
be NEC Class 1, and must comply with all applicable codes.
The furnace must be electrically grounded in accordance with
local codes or, in their absence, with the latest edition of The
National Electric Code, ANSI NFPA 70 and/or The Canadian
Electric Code CSA C22.1.
Use a separate fused branch electrical circuit containing prop-
erly sized wire, and fuse or circuit breaker. The fuse or circuit
breaker must be sized in accordance with the maximum over-
current protection specified on the unit rating plate. An electri-
cal disconnect must be provided at the furnace location.
Connect hot, neutral, and ground wires as shown in the wiring
diagram located on the unit’s blower door.
Line polarity must be observed when making field connections.
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 with the junction box located inside
the burner compartment (blower compartment for downflows).
To make electrical connections through the opposite side of
the furnace, the junction box must be relocated to the other
side of the burner (or blower) compartment prior to making
electrical connections. To relocate the junction box, follow the
steps shown below.
NOTE:
Wire routing must not to interfere with circulator blower
operation, filter removal, or routine maintenance.
J
UNCTION
B
OX
R
ELOCATION
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 connec-
tions. 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 junction box to
the right side of the furnace.
3. Models that have the junction box located in the burner
or blower compartment will need to move the junction
box directly over.
4. Attach the junction box to the left side of the furnace,
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 filter 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 accordance
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.
NOTE:
In downflow applications the power leads should be
routed through the supplied wire tabs when locating junction
box to the left side.
Low voltage wires may be connected to the terminal strip.
IMPORTANT NOTE:
To avoid possible equipment malfunction,
route the low voltage wires to avoid interference with filter re-
moval 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 junc-
tion 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 one of the burners.
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.
