F97CMN and G97CMN: Installation, Start-up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
28
A03193
Fig. 35 – Communication Connector
NOTE:
A = DX+, B = DX-, C = C, D = R
Outside Air Thermistor (OAT)
Used in conjunction with communicating User Interface. Not required
when a standard type thermostat is used. Refer to the instructions
supplied with the User Interface for details.
24-V Wiring
Make field 24-v connections at the 24-v terminal strip, see
.
Connect terminal Y/Y2 as shown in
for proper cooling operation.
Use only AWG No. 18, color-coded, copper thermostat wire.
NOTE:
Use AWG No. 18 color-coded copper thermostat wire for
lengths up to 100 ft. (31 M). For wire lengths over 100 ft., use AWG No.
16 wire.
The 24-v circuit contains an automotive-type, 3-amp. fuse located on the
control. Any direct shorts during installation, service, or maintenance
could cause this fuse to blow. If fuse replacement is required, use ONLY
a 3-amp. fuse of identical size, see
Thermostats
For best results, use a communicating wall control to control this
modulating furnace. A single stage or two-stage heating and cooling
thermostat can be used with the furnace. The furnace control board CPU
will control the furnace and outdoor unit staging. A two stage heating
and cooling thermostat can also be used to control the staging. However,
full modulating capability will not be available when the furnace staging
is controlled by the thermostat. Furnace staging will be limited to
Minimum and Maximum inputs or Intermediate and Maximum inputs
depending on the configuration of set-up switches SW1-2 and SW4-2.
For two stage thermostat control of a 2-stage outdoor unit, remove the
ACRDJ jumper from the furnace control board. Refer to typical
thermostat wiring diagrams and the Sequence of Operation section for
additional details. Consult the thermostat installation instructions for
specific information about configuring the thermostat, see
A11616
Fig. 36 – Example of Modulating Furnace Control
A
B
C
D