Electrical Connections - Control Wiring - Lennox LGT156H Installation Instructions Manual

TABLE 2
INVERTER UP-SIZING
Factory-Installed Inverter HP
2
3
5
7.5
10

Electrical Connections - Control Wiring

A-Thermostat Location
Room thermostat mounts vertically on a standard 2" X 4"
handy box or on any non-conductive flat surface.
Locate thermostat approximately 5 feet (1524mm)
above the floor in an area with good air circulation at
average temperature. Avoid locating the room
thermostat where it might be affected by:
-drafts or dead spots behind doors and in corners
-hot or cold air from ducts
-radiant heat from sun or appliances
-concealed pipes and chimneys
B-Wire Routing
Route thermostat cable or wires from subbase through
knockout provided in unit. Use 18 AWG wire for all
applications using remotely installed electro-mechanical
and electronic thermostats.
On hot gas reheat units, route wires from RH sensor or
remote switch through knockout provided in unit. For
sensor installations, use 22AWG stranded, two twisted
pairs, individually shielded, 100% aluminum shield with
drain wire and Teflon jacket.
IMPORTANT - Unless field thermostat wires are rated for
maximum unit voltage, they must be routed away from
line voltage wiring.
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
LGT/LCT156, 180, 210, 240, 300
Replacement Inverter HP
5
7-1/2
10
15
20
Page 12
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
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
SENSOR
IAQ
R C
AI1 HUM
A2 SENSOR
FIGURE 10
J297
A55
10
11
W1
W2
12
D
INPUTS
TMP
AI2 R
J298