13
24 Volt Thermostat Wiring
NOTE: Wire routing must not interfere with circu
-
lator 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 located 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)
This furnace is equipped with a 40 VA transformer to facili-
tate use with most cooling equipment. Consult the wiring di-
agram, located on the blower compartment door, for further
details of 115 Volt and 24 Volt wiring.
A single-stage thermostat with only one heating stage can be
used to control this furnace.
115 Volt Line Connection of Accessories
(Humidifier and Electronic Air Cleaner)
The furnace integrated control module is equipped with line
voltage accessory terminals for controlling power to an op-
tional field-supplied humidifier and/or electronic air cleaner.
Turn OFF power to the furnace before installing any acces-
sories. Follow the humidifier or air cleaner manufacturers’ in
-
structions for locating, mounting, grounding, and controlling
these accessories. Accessory wiring connections are to be
made through the 1/4” quick connect terminals provided on
the furnace integrated control module. The humidifier hot
terminal is identified as 120V HUM-H, its neutral terminal is
identified as 120V HUM-N. The electronic air cleaner hot ter
-
minal is identified as EAC-H, its neutral terminal is identified
as 120V EAC-N.All field wiring must conform to applicable
codes. Connections should be made as shown. (See Con-
necting Line Voltage Accessories.)
If it is necessary for the installer to supply additional line volt-
age wiring to the inside of the furnace, the wiring must con-
form 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.
WARNING
To prevent personal injury or death due to electric shock,
disconnect electrical power before installing or servicing
this unit.
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 burn-
er 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 rota-
tion 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. Metal
conduit is not considered a substitute for an actual ground
wire to the unit. 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 rotating junction box to the left side.
Low voltage wires may be connected to the terminal strip.
IMPORTANT NOTE: To avoid possible equipment mal
-
function, route the low voltage wires to avoid inter
-
ference with filter removal or other maintenance.
WARNING
HIGH VOLTAGE!
To 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
National Electrical Code.
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 per
-
form the following check.
1. Measure resistance between the neutral (white) con-
nection 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.
