Lennox SIGNATURE SLP99UHV Installation Instructions Manual page 35

Communicating Enabled Furnace and
Non-Communicating Outdoor Unit
COMMUNICATING
ENABLED FURNACE
OPTIONAL
DISCHARGE
AIR SENSOR
COMMUNICATING
THERMOSTAT
CLIP Y1 TO Y2 FOR
TWO-STAGE OPERATION
Outdoor Unit
Communicating systems using the a communicating thermostat require four
thermostat wires between the thermostat and the furnace/air handler control and
four wires between the outdoor unit and the furnace/air handler control. When
a thermostat cable with more than four wires is used, the extra wires must be
nected.
Use wire nuts to bundle the four unused wires at each end of the cable. A
single wire should then be connected to the indoor unit end of the wire bundle
and attached to the "C" terminals as shown in the diagram above.
OPTIONAL
OUTDOOR
AIR SENSOR
NON-COMMUNICATING
OUTDOOR AIR
CONDITIONING UNIT -
1 OR 2 STAGE
Indoor Unit
Controller
Single wire to
terminal C
Unused wires
FIGURE 52
Page 35
Communicating Enabled Furnace and
Communicating Enabled Outdoor Unit
COMMUNICATING
ENABLED FURNACE
OPTIONAL
DISCHARGE
AIR SENSOR
OPTIONAL
OUTDOOR
AIR SENSOR
COMMUNICATING
THERMOSTAT
Single wire to
terminal C
Unused wires
COMMUNICATING ENABLED
OUTDOOR UNIT
Communicating Thermostat