Lennox XC21 Series Unit Information page 25

XC21 Two−Stage Air
Conditioner Control
W
L
Y2
Y1
O
DS
C
2
4
R
1. Thermostat T terminals are used for outdoor sensor input. Use for thermostat's outdoor temperature display (optional).
2. R to L connection is required for this model when using the ComfortSense
47W97) required and ordered separately.
3. Cut on−board link W915 (clippable wire) for two−stage operation.
4. Cut loop jumper (clippable wire) Short DS to R for Humiditrol
must be installed between the DS terminals on the furnace and outdoor unit controls. See table 14 for fan speed based on unit capacity.
5. Cut on−board link (clippable wire) DS−R for Humiditrol
setting. See furnace installation instruction or engineering handbook for lowest fan speed information.
Figure 12. ComfortSense® 7000 Series Thermostat
Furnace
5
DS
O
L
H
DH
R
C
Y1
3
Y2
G
W2
W1
®
7000 − catalog number Y0349 only. Resistor Kit (catalog number
®
applications. This will slow the outdoor unit's fan speed to a specific RPM. A wire
® or Harmony IIIt applications. This will slow the indoor blower motor to the lowest speed
Furnace/Two−Stage Air Conditioner
Page 25
ComfortSense[ 7000 Thermostats
Catalog # Y0349 or Y2081
R
G
W2
W1
O
L
H
D
B
Y2
1
Y1
C
T
T
Non−Communicating Connections −
On−board link
Low voltage thermostat
wiring
XC21