Lennox LHT180 Installation Instructions Manual page 11

C-Wire Connections
The Unit Controller will operate the unit from a
thermostat or zone sensor based on the System Mode.
The default System Mode is the thermostat mode. Refer
to the Unit Controller Setup Guide to change the System
Mode. Use the mobile service app menu and select:
SETTINGS > INSTALL.
Note - Unit Controller is capable of up to four stages of
cooling in network control mode.
1- Default Thermostat Mode -
The Unit Controller will operate two stages of heating
and cooling based on thermostat demands. Install
thermostat assembly in accordance with instructions
provided with thermostat. See figure 9 for field wiring
and and refer to wiring diagrams on unit.
IMPORTANT-Terminal connections at the wall plate or
subbase must be made securely. Loose control wire
connections may result in intermittent operation.
FIELD WIRING WITH ELECTRONIC AND
ELECTRO-MECHANICAL THERMOSTATS
(Thermostat Mode)
24 V POWER
P297
1
R
2
C
3
G
4
W1
5
W2
6
Y1
7
Y2
8
OCP
9
10
FIGURE 9
J297
A55
10
11
W1
W2
12
D
2- Zone Sensor Mode -
The Unit Controller will operate heating and cooling
based on the Unit Controller internal setpoints and the
temperature from the A2 zone sensor. An optional
Network Control Panel (NCP) can also be used to provide
setpoints. A thermostat or return air sensor can be used
as a back-up mode. Make zone sensor wiring
connections as shown in figure 10.
Note - Install sensor and make communication wiring
connections as shown in literature provided with sensor.
FIELD WIRING IN ZONE SENSOR MODE
(Zone Sensor Mode)
UNIT CONTROLLER
SENSOR
24VAC
IAQ
R C
AI1
Page 11
SENSOR INPUTS
HUM
TMP
AI2 R
A2 SENSOR
FIGURE 10
508336-01
J298
1/2023