Page 25
XC21
Y1
O
R
W1
G
D
R
Y1
L
C
C
B
Y2
Y2
W
O
DS
L
T
T
W2
H
H
O
C
L
Y2
DS
DH
G
R
Y1
W2
W1
1
2
4
5
Furnace
ComfortSense[ 7000 Thermostats
Catalog # Y0349 or Y2081
XC21 Two−Stage Air
Conditioner Control
On−board link
Low voltage thermostat
wiring
3
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
®
7000 − catalog number Y0349 only. Resistor Kit (catalog number
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
®
applications. This will slow the outdoor unit’s fan speed to a specific RPM. A wire
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
®
or Harmony IIIt applications. This will slow the indoor blower motor to the lowest speed
setting. See furnace installation instruction or engineering handbook for lowest fan speed information.
Figure 12. ComfortSense® 7000 Series Thermostat Non−Communicating Connections −
Furnace/Two−Stage Air Conditioner