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508117-01 2/2021
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.
FIGURE 9
FIELD WIRING WITH ELECTRONIC AND
ELECTRO-MECHANICAL THERMOSTATS
(Thermostat Mode)
J262C
10
11
12
J297
P297
1
2
3
4
5
6
7
8
9
10
24 V POWER
W1
W2
P262
A55
R
OCP
C
G
W1
W2
Y1
Y2
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
.
FIGURE 10
FIELD WIRING IN ZONE SENSOR MODE
(Zone Sensor Mode)
A2 SENSOR
INPUTS
SENSOR
SENSOR
24VAC
R
C
IAQ
HUM
AI1
AI2
TMP
R
UNIT CONTROLLER
J298
D-Hot Gas Reheat Units Only
1- Install humidity sensor in accordance with instructions
provided with sensor. A DDC input may be used to
initiate dehumidification instead of a sensor.
2- Make wiring connections as shown in figure 9 for
Thermostat Mode and figure 10 for Zone Sensor
Mode. In addition, connect either a humidity sensor
or a dehumidification input. See figure 11 or 12 for
humidity sensor wiring and figure 13 for
dehumidification input wiring.
Humidity Sensor Cable Applications:
Wire runs of 50 feet (mm) or less:
Use two separate shielded cables containing 20AWG
minimum, twisted pair conductors with overall shield.
Belden type 8762 or 88760 (plenum) or equivalent.
Connect both cable shield drain wires to TB1-7 as shown
in figure 11.
Wire runs of 150 feet (mm) or less:
Use two separate shielded cables containing 18AWG
minimum, twisted pair conductors with overall shield.
Belden type 8760 or 88760 (plenum) or equivalent.
Connect both cable shield drain wires to TB1-7 as shown
in figure 11.
Wire runs over 150 feet (mm):
Use a local, isolated 24VAC transformer such as Lennox
cat #18M13 (20VA minimum) to supply power to RH
sensor as shown in figure 12. Use two shielded cables
containing 20AWG minimum, twisted pair conductors
with overall shield. Belden type 8762 or 88760 (plenum)
or equivalent.
