Lennox SL280UHNV Installation Instructions Manual page 23

Communicating Enabled Furnace and Non-
Communicating Outdoor Unit
COMMUNICATING FURNACE
OPTIONAL
DISCHARGE
AIR SENSOR
COMMUNICATING
THERMOSTAT
CLIP ON-BOARD LINK
W915 (Y1 TO Y2) FOR
TWO-STAGE OPERATION
Outdoor Unit
OPTIONAL
OUTDOOR
AIR SENSOR
NON-COMMUNICATING
OUTDOOR AIR
CONDITIONING UNIT -
1 OR 2 STAGE
nace/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 properly connected to avoid electrical noise. The wires must not be left
disconnected.
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 below.
Communicating Integrated Control
FIgURE 22
Page 23
Communicating Enabled Furnace and
Communicating Enabled Outdoor Unit
COMMUNICATING FURNACE
OPTIONAL
DISCHARGE
AIR SENSOR
OPTIONAL
OUTDOOR
AIR SENSOR
COMMUNICATING
THERMOSTAT
DOOR AIR CONDITIONING
OR HEAT PUMP UNIT
Communicating Thermostat