Service Manual

INSTALLATION CONSIDERATIONS
28
WARNING
HIGH VOLTAGE
D
ISCONNECT ALL POWER BEFORE SERVICING OR
INSTALLING THIS UNIT.
MULTIPLE POWER SOURCES MAY
BE PRESENT.
FAILURE TO DO SO MAY CAUSE PROPERTY
DAMAGE, PERSONAL INJURY OR DEATH.
CAUTION
L
ABEL ALL WIRES PRIOR TO DISCONNECTION WHEN SERVICING CONTROLS.
WIRING ERRORS CAN COUSE IMPROPER AND DANGEROUS OPERATION.
V
ERIFY PROPER OPERATION AFTER SERVICING.
WIRING HARNESS
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.
Refer 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 tempera-
ture rating of at least 105° C. Any replacement wiring must
be copper conductor.
115 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 fur-
nace must be N.E.C. 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
properly sized wire, and fuse or circuit breaker. The fuse or
circuit breaker must be sized in accordance with the maxi-
mum overcurrent protection specified on the unit rating plate.
An electrical disconnect must be provided at the furnace
location.
NOTE: Line polarity must be observed when making field
connections.
W
A
R
N
I
N
G
IN 90% FURNACE UPRIGHT UPFLOW INSTALLATIONS, THE DRAIN TRAP MUST
BE MOUNTED ON THE OPPOSITE SIDE OF THE UNIT FROM THE JUNCTION
BOX.
THIS WILL REDUCE THE RISK OF WATER REACHING THE JUNCTION
BOX IN THE EVENT OF A BLOCKED DRAIN CONDITION.
Connect hot, neutral, and ground wires as shown in the wir-
ing diagram located on the unit’s blower door. Line polarity
must be observed when making field connections. Line volt-
age connections can be made through either the right or left
side pan.
NOTE: Wire routing must not interfere with circulator blower
operation, filter removal, or routine maintenance.
WARNING
TO AVOID THE RISK OF ELECTRICAL SHOCK, INJURY, 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
HIGH VOLTAGE
D
ISCONNECT
ALL
POWER BEFORE SERVICING OR
CHANGING ANY ELECTRICAL WIRING.
MULTIPLE POWER
SOURCES MAY BE PRESENT.
FAILURE TO DO SO MAY CAUSE
PROPERTY DAMAGE, PERSONAL INJURY OR DEATH.
24 VOLT HUMIDIFIER
A 24 volt humidifier can be connected to the normally open
terminal of the main pressure switch. The humidifier com-
mon would then be connected to "C" on the control board
low voltage terminal strip.
If it is necessary for the installer to supply additional line
voltage wiring to the inside of the furnace, the wiring must
conform to all local codes, and have a minimum temperature
rating of 105°C. All line voltage wire splices must be made
inside the furnace junction box.
24 VOLT THERMOSTAT WIRING
NOTE: Low voltage connections can be made through either
the right or left side panel. Wire routing must not interfere
with circulator blower operation, filter removal, or routine main-
tenance.
A 40 V.A. transformer and an integrated electronic control
are built into the furnace to allow use with most cooling equip-
ment. Consult the wiring diagram, located in the Technical
Manual or on the blower door for further details of 115 Volt
and 24 Volt wiring.
THERMOSTAT WIRING
The single stage furnace will have a "W" terminal and will
use a single stage thermostat. The following drawing illus-