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4. Before connecting the thermostat wiring, check to make
sure the wires will be long enough for servicing at a
later date. Remove the blower access panel to check
the length of the wire.
5. Complete the wiring connections to the equipment. Use
the provided unit wiring diagram and the field wiring
diagram shown in Figures 24 and 25. Use 18 gauge
wire or larger that is suitable for Class II rating for
thermostat connections.
6. 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). A green
ground wire is provided in the field make-up box.
NOTE: This furnace contains electronic components that
are polarity sensitive. Make sure that the furnace is wired
correctly and is properly grounded.
7. One line voltage "AAC" 1/4" spade terminal is provided
on the furnace integrated control. Any electronic air
cleaner or other accessory rated up to one amp can be
connected to this terminal with the neutral leg of the
circuit being connected to one of the provided neutral
terminals. See Figure 26 for control configuration. This
terminal is energized when the indoor blower is
operating.
8. An unpowered, normally open (dry) set of contacts with
a 1/4" spade terminal "HUM" are provided for humidifier
connections and may be connected to 24V or 120V. Any
humidifier rated up to one amp can be connected to
these terminals. In 120V humidifier applications the
neutral leg of the circuit can be connected to one of the
provided neutral terminals, the terminal is energized in
the heating mode.
9. Install the room thermostat according to the instructions
provided with the thermostat. If the furnace is being
matched with a heat pump, refer to the instruction
packaged with the dual fuel thermostat.
Thermostat Selection
CAUTION
Field wiring for both communicating and non-
communicating applications is illustrated in diagrams,
which begins on Page 24.
Page 22 of 64
Table 12
Non-Communicating
In non-communication applications this furnace is designed
to operate in a SINGLE-STAGE mode or TWO-STAGE
mode using a convention thermostat.
For optimal performance in non-communicating
applications, use a high quality electronic digital thermostat
or any other with adjustable settings for 1st stage / 2nd
stage ON/OFF differentials and adjustable stage timers.
Communicating
In communicating applications the Comfort Sync™
thermostat must be used. Refer to the instructions provided
with the thermostat for installation, set-up and operation. In
communicating systems all unused thermostat wire in the
wire bundle needs to be terminated inside and out. The
extra wires can terminate on the "C" terminal of the Comfort
Sync™ communication terminal strip. Using an additional
wire come off "C" terminal and wire nut all the extra wires
together. Termination on the outdoor control must match
the indoor control.
Indoor Blower Speeds
Non-Communicating
When the thermostat is set to "FAN ON", the indoor blower
will run continuously at approximately 38% of the second
stage cooling speed when there is no cooling or heating
demand.
When the furnace is running in the heating mode, the indoor
blower will run on the heating speed designated by the
positions of DIP switches 11, 12 and 13.
When there is a cooling demand, the indoor blower will run
on the cooling speed designated by the positions of DIP
switches 5 and 6. First stage cooling will run at 70% cool
speed.
Communicating
NOTE: When this furnace is used with a Comfort Sync™
thermostat, proper indoor blower speed selections are made
by the communicating thermostat.
When the thermostat is set to "FAN ON", the indoor blower
will run at setting determined during system configuration.
When there is a heating demand the fan will run on heating
speeds for firing rate.
When there is a cooling demand, the fan will run on the first
stage and second stage cooling speed set using the Comfort
Sync™ thermostat in the installer setup mode. The factory
default is based upon 400 CFM per ton.
Issue 1251
506892-01
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