Fully Communicating Daikin System; Overview; Airflow Consideration; Thermostat Wiring - Daikin EEV Series Installation Instructions Manual

17 FULLY COMMUNICATING DAIKIN SYSTEM
NOTE: For a detailed procedure of thermostat commission-
ing process, please visit the Daikin One+ website at
http://www.daikinone.com

17.1 Overview

A fully communicating Daikin system is a system that
includes a compatible air handler and air conditioner or
heat pump with a communicating thermostat.
A fully communicating Daikin heating/air conditioning sys-
tem differs from a non-communicating/traditional system
in the manner in which the indoor unit, outdoor unit and
thermostat interact with one another. In a traditional sys-
tem, the thermostat sends commands to the indoor and
outdoor units via analog 24 VAC signals. It is a one-way
communication path. The indoor and outdoor units typically
do not return information to the thermostat.
For a fully communicating Daikin system, the indoor unit,
outdoor unit, and thermostat "communicate" digitally with
one another. It is now a two-way communications path.
The thermostat still sends commands to the indoor and
outdoor units and may also request and receive information
from both the indoor and outdoor units. This information
may be displayed on the communicating thermostat. The
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
between the thermostat and subsystems (indoor/outdoor
unit) is the key to unlocking the benefits and features of
the fully comunicating Daikin system.
Two-way digital communications is accomplished using
only two wires. The thermostat and air handler controls
are powered with 24 VAC. A maximum of 4 wires between
the air handler and thermostat is required to operate the
system. An inverter equipped outdoor unit does not re-
quire 24 VAC. Only the 2 digital communication wires are
required between the air handler and inverter unit (pins 1
and 2 on the thermostat connector.)

17.2 Airflow Consideration

Airflow demands are managed differently in a fully com-
municating system than in a non-communicating wired
system. The system operating mode (as determined by the
thermostat) determines which unit calculates the system
airflow demand. If the indoor unit is responsible for deter-
mining 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. Table 11 lists the various fully
communicating Daikin systems, the operating mode, and
airflow demand source.
For example, assume the system is a heat pump matched
with an air handler. With a call for low stage cooling, the
heat pump will calculate the system's low stage cooling
airflow demand. The heat pump 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.
See the applicable fully communicating Daikin System
air conditioner or heat pump installation manual for the
airflow delivered during cooling or heat pump heating.
In continuous fan mode, the communicating thermostat
provides the airflow demand. The communicating
thermostat provides 4 continuous fan speeds (25%, 50%,
75% and 100% of maximum airflow). During continuous
fan operation, the thermostat sends a fan request along
with the continuous fan demand to the air handler. The air
handler, in turn, sends the demand to the ECM motor. The
ECM motor delivers the requested continuous fan airflow.

17.3 Thermostat Wiring

NOTE: Refer to section Electrical Connections for
208/230 volt line connections to the air handler.
NOTE: It is STRONGLY recommended that no more
than two wires be connected in a single terminal. If two
wires are used in a terminal, it is recommended the
same type of wire be used (i.e. Both stranded or solid
for secure connection). Failure to do so may result in
intermittent operation.
Typical 18 AWG thermostat wire may be used to wire the
system components. Two hundred fifty (250) feet is the
maximum of wire between indoor unit and outdoor unit,
and one hundred twenty five (125) feet between indoor
unit and thermostat.
17.3.1 Two-Wire Outdoor and Four-Wire Indoor
Wiring
Typical wiring will consist of two wires between the
indoor unit and outdoor unit and four wires between
the indoor unit and thermostat. Figure 20 shows the
required wires are: data lines, 1 and 2; "R" (24 VAC
hot) and "C" (24 VAC common).

17.4 Network Troubleshooting

Occasionally the need to troubleshoot the network may
arise. The integrated air handler control has some on-
board tools that can be used to troubleshoot the network.
These tools are: red communications LED, green receive
(Rx) LED, and the learn button. Refer to the Communi-
cations Troubleshooting Chart at the end of this manual
for error codes, possible causes and corrective actions
• Red communications LED – Indicates the status of
the network. The Communications Troubleshooting
Chart on the following page indicates the LED status
and the corresponding potential problem.
• Green receive LED – Indicates network traffic. The
following table indicates the LED status and the corre-
sponding potential problem.
• Learn button – Used to reset the network. Depress
the button for approximately 2 seconds to reset the
network.
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