Electrical Connections - Control Wiring - Lennox LGT092H Installation Instructions Manual

Electrical Connections - Control Wiring

NOTE ‐ Optional wireless sensors are available for use
with this unit. Refer to the instructions provided with
each sensor.
CAUTION
Electrostatic discharge can affect electronic com­
ponents. Take precautions during unit installation
and service to protect the electronic controls. Pre­
cautions will help to avoid control exposure to elec­
trostatic discharge by putting the unit, the control
and the technician at the same electrostatic poten­
tial. Neutralize electrostatic charge by touching
hands and all tools on an unpainted unit surface,
such as the gas valve or blower deck, before per­
forming any service procedure.
A-Thermostat Location
Applied to units in default thermostat control mode only.
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.
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-Control Wiring
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.
Thermostat Mode
1- Route thermostat cable or wires from subbase to
control area above compressor (refer to unit
dimensions to locate bottom and side power entry).
IMPORTANT - Unless field thermostat wires are rated
for maximum unit voltage, they must be routed away
from line voltage wiring. Use wire ties located near the
lower left corner of the controls mounting panel to
secure thermostat cable.
Use18 AWG wire for all applications using remotely
installed electro-mechanical
thermostats.
2- Install thermostat assembly in accordance with
instructions provided with thermostat.
Avoid locating the
and electronic
3- Connect thermostat wiring to Unit Controller on the
lower side of the controls hat section.
4- Wire as shown in figure 15 for electro-mechanical
and electronic
temperature control devices or energy management
systems see instructions and wiring diagram
provided by manufacturer.
IMPORTANT-Terminal connections at the Unit Controller
must be made securely. Loose control wire connections
may allow unit to operate but not with proper response to
room demand.
Zone Sensor Mode
The Unit Controller will operate heating and cooling
based on the Unit Controller internal setpoints and the
temperature from the A2 room 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 room sensor wiring
connections as shown in figure 16.
C-Hot Gas Reheat Units Only -
1- Install humidity
instructions provided with sensor. A DDC input may
room
be used to initiate dehumidification instead of a
sensor.
2- Make wiring connections as shown in figure 15 for
Thermostat Mode or figure 16 for Zone Sensor
Mode. In addition, connect either a humidity
sensor or a dehumidification input. See figure 18
or 19 for humidity sensor wiring or figure 17 for
dehumidification input wiring.
24 VOLT FIELD WIRING IN THERMOSTAT MODE
24 V POWER
R
C
G
W1
W2
Y1
Y2
OCP
Page 11
thermostats.
sensor in accordance
J297A P297
A55
1
2
B
3
W1
4
5 W2
6
7
8
C
9
D
10
FIGURE 15
If using other
with
10
11
12