Daikin RXSQ24TAVJU Service Manual page 99

SiUS331708EA
6.17.3 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.
Stop the thermostat ON signal (∗1)
to the economizer.
∗1. Thermostat ON signal: A signal to turn ON the indoor unit thermostat and allow the economizer
∗2. External input ON is an input signal to the X1M-ECONOMIZER1 terminal on the PCB.
∗3. Refer to Optional Kit Setting (UV lamp + Humidifier + Economizer) (for FXTQ-TA and CXTQ-TA
∗4. Remote control ON signal: Contact output which shows the operating status of the indoor unit.
Functions and Control
Thermostat ON signal
Operation
Normal operation
• Cooling mode
Other
• When the thermostat is ON
&
conditions
• External output: ON (∗2)
Free cooling
• Air conditioner operation is
stopped.
• The remote controller indicates
cooling operation.
• The fan tap follows the remote
controller.
Indoor unit ON signal
Stop indoor unit ON signal (∗4)
to the economizer.
to open the damper.
It turns ON the relay on the X2M-ECONOMIZER2 on the PCB.
models) on page 106.
This signal turns on the relay X2M-CONTROL ON/OFF on the PCB.
• Cooling mode
&
• When the thermostat is ON
Other conditions
• Economizer set time (∗3) ≠
Free cooling only
&
• Thermostat ON continues for
the economizer set time (∗3)
• Tcon ≤ Ts' continues for 1
minute
OR
• Economizer set time (∗3):
Free cooling only
Remote control ON
Remote control OFF
Outline of Control (Indoor Unit)
Transfer the thermostat ON signal (∗1) to
the economizer.
Free cooling & Mech Cooling
• Air conditioner operation is
started.
• The remote controller
indicates cooling operation.
• The fan tap follows the
remote controller.
Transfer indoor unit ON signal (∗4) to the
economizer.
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