Daikin SkyAir GQI-Eco Series Service Manual page 47

SiBE281013
3.2.8 General Electronic Expansion Valve Control
When cooling/heating, PI control of electronic expansion valve is conducted to keep the heat
exchanger outlet subcooling degree constant.
•
•
∗
3.2.9 Hot Start Control (Only in Heating Operation)
In heating, when performing a startup, or after the defrosting cycle has been completed, the
indoor fan will be controlled in order to prevent cold air draft and secure the starting
performance (quick pressure build-up).
Indoor unit fan: OFF
Indoor unit fan: LL tap
Indoor unit fan: L tap
Indoor unit fan: M tap
Indoor unit fan: Set fan speed
Function and Control
Target heat exchanger outlet subcooling degree > actual heat exchanger outlet subcooling
degree
→
The electronic expansion valve will close.
Target heat exchanger outlet subcooling degree < actual heat exchanger outlet subcooling
degree
→
The electronic expansion valve will open.
The value of target heat exchanger outlet subcooling degree varies depending on change of
discharge pipe superheat degree of inverter compressor, etc.
Heating operation is turned ON with remote controller.
(
• 1 minute elapsed with LL tap
&
OR
(
• 1 minute elapsed with L tap
&
OR
(
• 1 minute elapsed with M tap
&
OR
Condition
A Indoor unit heat exchanger temperature > 34°C
Indoor unit heat exchanger temperature > indoor suction
B air temperature +17°C
(+12°C if outdoor air temperature is < 5°C)
Indoor unit heat exchanger temperature > indoor suction
C air temperature +22°C
(+20°C if outdoor air temperature is < 5°C)
• Condition A is met.
(
• Condition B is met.
• 3 minutes elapsed after compressor startup
• Condition A is met.
(
• Condition B is met.
• 5.5 minutes elapsed after compressor startup
(Continuing L tap on indoor unit without M tap equipped)
• Condition A is met.
(
• Condition C is met.
• 10.5 minutes elapsed after compressor startup
Function Details
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