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Electrical
CAUTION
Electrostatic discharge can affect electronic com
ponents. Take precautions during furnace installa
tion and service to protect the furnace's electronic
controls. Precautions will help to avoid control ex
posure to electrostatic discharge by putting the fur
nace, the control and the technician at the same
electrostatic potential. Neutralize electrostatic
charge by touching hand and all tools on an un
painted unit surface, such as the gas valve or blow
er deck, before performing any service procedure.
These units operate on 120 volt, single phase, 60 hz
electrical power. Refer to figure 20 for field wiring and
figure 22 for schematic wiring diagram and trouble
shooting.
1 - Select circuit protection and wire size according to the
unit rating plate.
2 - Knockouts are provided on both sides of the furnace
cabinet to facilitate wiring.
3 - Install the room thermostat according to instructions
provided with the thermostat.
4 - Install a separate disconnect switch (protected by ei
ther fuse or circuit breaker) near the unit so power can
be turned off for servicing.
5 - Before connecting the thermostat or the power wiring,
check to make sure the wires will be long enough to
facilitate servicing at a later date. Remove the blower
access panel and open the panel to check wire length
for access.
6 - Complete wiring connections to the equipment using
wiring diagram provided with unit and wiring diagrams
shown in figures 20 and 22. Use 18 gauge wire or larg
er for thermostat connections.
7 - Electrically ground the unit according to local codes or,
in the absence of local codes, according to the current
National Electric Code (ANSI/NFPA No. 70) for the
USA and current Canadian Electric Code part 1 (CSA
standard C22.1) for Canada.
NOTE - The G24M furnace contains electronic com
ponents that are polarity sensitive. Make sure that
the furnace is wired correctly and is properly
grounded.
8 - One line voltage accessory ACC" terminal is provided
on the furnace control board with a protective plastic
cap. Any accessory rated up to 4 amps can be con
nected to this terminal (after removing the protective
cap) with the neutral leg of the circuit being connected
to the line voltage neutral wire. See figure 21 for con
trol board configuration. This terminal is energized
whenever the blower is in operation.
9 - One line voltage heating accessory HTG ACC" termi
nal is provided on the furnace control board with a pro
tective plastic cap. Any accessory rated up to 4 amps
can be connected to this terminal (after removing the
protective cap) with the neutral leg of the circuit being
connected to the line voltage neutral wire. See figure
21 for control board configuration. This terminal is en
ergized in the heating mode whenever the blower is in
operation.
Indoor Blower Speeds (Refer to Figure 22)
1 - When the thermostat is set to FAN ON", the indoor
blower will run continuously on low speed when there
is no cooling or heating demand.
2 - When the G24M is running in the heating mode, the in
door blower will run on the heating speed.
3 - When there is a cooling demand, the indoor blower will
run on the cooling speed.
