Daikin VRV IV-S RXTQ-TAVJU Series Service Manual page 84

Outline of Control (Indoor Unit)
6.13.2 Economizer
When indoor and outdoor air temperatures are reversed, the compressor is stopped to let in the
outdoor air to save energy.
This operation is called economizer operation, and the equipment to detect indoor and outdoor air
temperatures and open and close the damper to perform this operation is called an economizer.
The economizer detects indoor and outdoor air temperatures, informs the air conditioner that the
economizer operation is ready, and opens and closes the damper.
The indoor unit stops the outdoor unit when it receives a signal from the economizer and performs
air supply operation.
When the indoor air temperature is cooled down sufficiently by the economizer operation, and it is
no longer necessary (thermostat OFF), the indoor unit outputs a signal to the economizer to close
the damper.
Stop Thermostat ON signal (∗1)
to the economizer.
∗1. Thermostat ON signal: A signal to turn ON the indoor unit thermostat and allow the economizer
Note:
∗2. External input ON is an input signal to the "X11A" terminal on the PCB (A3P).
∗3. To stop the compressor while the economizer is in operation to save energy.
∗4. Remote control ON signal: Contact output which shows the operating status of the indoor unit.
6.13.3 Air Purifier (UV lamp)
When an air purifier is connected onsite, the fan is operated with the airflow rate set of the remote
controller or with the H tap.
∗1. External input ON is an input signal to the "X25A" terminal on the PCB (A3P).
Note:
71
Normal operation
Stop indoor unit ON signal (∗4)
to the economizer.
to open the damper.
It turns ON the relay on the "X8A side of X23A" on the PCB (A3P).
This signal turns on the relay "on the opposite side of X8A of X23A" on the PCB (A3P).
• Remote control operation
& (including thermostat OFF)
• External input = ON (∗1)
• Cooling mode
&
• When the thermostat is ON
Elimination of others
• Cooling mode
• When the thermostat is ON
&
• External input = ON (∗2)
Elimination of others
Remote control ON
Remote control OFF
Transfer Thermostat ON signal (∗1) to the
economizer.
• Transfer the thermostat OFF state to
the outdoor unit. (∗3)
• EV = 0 pulse
• The remote controller indicates cooling
operation.
• The fan tap follows the remote
controller.
Transfer indoor unit ON signal (∗4) to the
economizer.
Fan x tap operation
(Same operation as with the airflow rate selected
with the remote controller)
SiUS331604E
Functions and Control