Airflow Considerations; Ctk04 Standard Wiring Scheme; Control Wiring; System Wiring - Daikin ComfortNet DX16TC Series Service Instructions Manual

SERVICING
indoor and outdoor units also interact with one another. The
outdoor unit may send commands to or request information
from the indoor unit. This two-way digital communications be-
tween the thermostat and subsystems (indoor/outdoor unit)
and between subsystems is the key to unlocking the benefits
and features of the ComfortNet system.
Two-way digital communications is accomplished using only
two wires. The thermostat and subsystem controls are pow-
ered with 24 VAC Thus, a maximum of 4 wires between the
equipment and thermostat is all that is required to operate the
system.

AIRFLOW CONSIDERATIONS

Airflow demands are managed differently in a fully communi-
cating system than they are in a legacy wired system. The sys-
tem operating mode (as determined by the thermostat) deter-
mines which unit calculates the system airflow demand. If the
indoor unit is responsible for determining the airflow demand,
it calculates the demand and sends it to the ECM motor. If the
outdoor unit or thermostat is responsible for determining the
demand, it calculates the demand and transmits the demand
along with a fan request to the indoor unit. The indoor unit
then sends the demand to the ECM motor. The following table
lists the various ComfortNet™ systems, the operating mode,
and airflow demand source.
For example, assume the system is an air conditioner matched
with an air handler. With a call for low stage cooling, the air
conditioner will calculate the system's low stage cooling air-
flow demand. The air conditioner will then send a fan request
along with the low stage cooling airflow demand to the air
handler. Once received, the air handler will send the low stage
cooling airflow demand to the ECM motor. The ECM motor
then delivers the low stage cooling airflow. The table below
lists the nominal high and low stage airflow for the ComfortNet
air conditioners and heat pumps.
Cooling
Models
High
*SZC160241 800
*SZC160361 1200
*SZC160481 1550
*SZC160601 1800
*SZC180361 1250
*SZC180481 1750
*SZC180601 1750
Heating
Low High Low
600 800 600
800 1200 800
1100 1550 1100
1210 1800 1210
850 1250 850
1210 1750 1210
1210 1750 1210

Control Wiring

NOTE: Refer to section Electrical Connections - High Voltage
Connections for 208/230 volt line connections to the air condi-
tioner or heat pump.
NOTE: A removable plug connector is provided with the
control to make thermostat wire connections. This plug may
be removed, wire connections made to the plug, and replaced.
It is strongly recommended that you do not connect multiple
wires into a single terminal. Wire nuts are recommended to
ensure one wire is used for each terminal. Failure to do so may
result in intermittent operation.
Typical 18 AWG thermostat wire may be used to wire the
system components. 150 feet is the maximum length of wire
recommended between indoor unit and outdoor unit, or be-
tween indoor unit and thermostat.

CTK04 STANDARD WIRING SCHEME:

Two wires may be utilized between the indoor and outdoor
units. For this wiring scheme, only the data lines, 1 and 2,
are required between the indoor and outdoor units. A 40VA,
208/230 VAC to 24 VAC transformer must be installed in the
outdoor unit to provide 24 VAC power to the outdoor unit's
electronic control. The "C" 24v common of the outdoor trans-
former should be grounded to the equipment (earth) ground.
The transformer is included with the CTK0* kit. See kit instruc-
tions for mounting and wiring instructions. Four wires are
required between the indoor unit and thermostat.
40VA Transformer (included in
CTK04 kit)
24 VAC
208/230 VAC

System Wiring

34
Thermostat
1 2 R C
Air Handler/Furnace/PCB
1 2 R C
AC/HP/ PCB
1 2 R C
(Ground Indicator)
Note: Recommended (Field Provided)