Daikin VRV RXYQ72-384XAYCA, Service Manual

Page: 138 / 419

Outline of Control (Indoor Unit) SiUS342004EB
131 Part 4 Functions and Control
Note(s)
9.16.3 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.
&
Other conditions
Stop the thermostat ON signal (
∗
1)
to the economizer.
Transfer the thermostat ON signal (
∗
1) to
the economizer.
•
Cooling mode
•
When the thermostat is ON
Thermostat ON signal
&

Cooling mode

When the thermostat is ON

External output: ON (

2)
OR

Tcon
≤
Ts’ continues for 1
minute

Economizer set time (

3):
Free cooling only
&

Economizer set time (

3)
≠
Free cooling only

Thermostat ON continues for
the economizer set time (

3)

Air conditioner operation is
stopped.

The remote controller indicates
cooling operation.

The fan tap follows the remote
controller.

Air conditioner operation is
started.

The remote controller
indicates cooling operation.

The fan tap follows the
remote controller.
Normal operation
Other
conditions
Free cooling Free cooling & Mech Cooling
Operation
Remote control ON
Remote control OFF
Stop indoor u nit ON signal (
∗
4)
to the economizer.
Transfer indoor u nit ON signal (
∗
4) to the
economizer.
Indoor unit ON signal

1. Thermostat ON signal: A signal to turn ON the indoor unit thermostat and allow the
economizer to open the damper. It turns ON the relay on the X2M-ECONOMIZER2 on the
PCB.
 2. External input ON is an input signal to the X1M-ECONOMIZER1 terminal on the PCB.
 3. Refer to Optional Kit Setting (UV lamp + Humi Economizer) (for FXTQ-TA,
FXTQ-TB, CXTQ-TA models) on page 161.
 4. Remote control ON signal: Contact output which shows the operating status of the indoor
unit. This signal turns on the relay X2M-CONTROL ON/OFF on the PCB.