Field Control Wiring - Lennox Signature XP21 Series Installation And Service Procedure

Field Control Wiring

The following two illustrations provide examples on how to install control wiring using a non−communicating thermostat. For
examples of how to install control wiring in complete or partial communicating systems, see the icomfortt thermostat Quick
Start Guide which is provided with the thermostat.
XP21 Two−Stage
Heat Pump Control
W
L
Y2
Y1
O
DS
2
C
7
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. Air handler control ships from factory with metal jumpers installed across W1, W2 and W3. For one−stage electric heat, do not remove factory
installed metal jumpers.
4. Air handler control ships from factory with metal jumpers installed across W1, W2 and W3. For two−stage electric heat, remove factory installed
metal jumper between W1 to W2. Then connect thermostat wire between the air handler control's W2 and the thermostat's W2 terminal.
5. Cut on−board link (clippable wire) from R−O HEAT PUMP for heat pump applications.
6. Cut on−board link (clippable wire) from Y1−Y2 2 STAGE COMPR for two−stage compressor and two−speed fan operation.
7. Cut loop jumper (clippable wire) Short DS to R for Humiditrol
must be installed between the DS terminals on the air handler and outdoor unit controls. See table 17 for fan speed based on unit capacity.
8. Cut on−board link (clippable wire) DS−R for Humiditrol
setting. See air handler installation instruction or engineering handbook for lowest fan speed information.
Figure 13. ComfortSense® 7000 Series Thermostat
XP21
Air Handler Control
DS
8
O
5
L
H
DH
R
C
Y1
6
Y2
G
W3
3
W2
4
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
Page 24
ComfortSense[ 7000 Thermostats
Catalog # Y0349 or Y2081
R
G
W2
W1
O
L
H
D
B
Y2
1
Y1
C
T
T
Air Hander/Two−Stage Heat Pump
On−board link
Low voltage thermostat
wiring
Flat metal jumper