Controls At Mode Changing / Start-Up - Daikin C-Series Service Manual

Control Specification
3.3

Controls at Mode Changing / Start-up

3.3.1 Preheating Operation
Outline The inverter operation in open phase starts with the conditions of the outdoor temperature, the
discharge pipe temperature, and the radiation fin temperature (internal temperature of PM1).
Outdoor temperature ≥ 10°C → Control A (preheating for normal state)
Detail
Outdoor temperature < 10°C → Control B (preheating of increased capacity)
Control A
Control B
3.3.2 Four Way Valve Switching
Outline In heating operation, current is conducted, and in cooling and defrosting, current is not
conducted. In order to eliminate the switching sound when the heating is stopped, as the four
way valve coil switches from ON to OFF, the OFF delay switch of the four way valve is carried
out after the operation stopped.
Detail OFF delay switch of four way valve:
The four way valve coil is energized for 150 seconds after the operation is stopped.
3.3.3 Four Way Valve Operation Compensation
Outline At the beginning of the operation as the four way valve is switched, the differential pressure to
activate the four way valve is acquired by having output frequency which is more than a certain
fixed frequency, for a certain fixed time.
Detail Starting Conditions
1. When starting compressor for heating.
2. When the operation mode changes to cooling from heating.
3. When starting compressor for defrosting or resetting.
4. When starting compressor for the first time after the reset with the power is ON.
5. When starting compressor for heating next to the suspension of defrosting.
6. When starting compressor next to the fault of switching over cooling / heating.
Set the lower limit frequency
32
ON condition
Discharge pipe temperature < 6°C
Radiation fin temperature < 85°C
OFF condition
Discharge pipe temperature > 8°C
Radiation fin temperature ≥ 90°C
ON condition
Discharge pipe temperature < 10.5°C
Radiation fin temperature < 85°C
OFF condition
Discharge pipe temperature > 12°C
Radiation fin temperature ≥ 90°C
(Hz) (seconds)
48 70
Hz for seconds with any conditions 1 through 6 above.
SiBE07-618_C
Function and Control