Daikin SUPER MULTI NX G Series Service Manual page 67

SiUS12-928_A
3.13.3 Refrigerant Shortage Control
Outline
I Detecting by power consumption
If the power consumption is below the specified value and the frequency is higher than the
specified frequency, it is regarded as refrigerant shortage.
The power consumption is small comparing with that in the normal operation when refrigerant is
insufficient, and refrigerant shortage is detected by checking a power consumption.
II Detecting by discharge pipe temperature
If the discharge pipe temperature is higher than the target discharge pipe temperature, and the
electronic expansion valve is fully open for more than the specified time, it is regarded as a
refrigerant shortage.
Refer to "Refrigerant shortage" on page 143 for detail.
3.13.4 Anti-icing Function
During cooling, if the heat exchanger temperature in the operation-stopped room lowers more than
the specified temperature for the specified time, the electronic expansion valve is opened in the
operation-stopped room, and fully closed operation is carried out. After this, if freezing abnormality
occurs longer than the specified time, the system shuts down as a system abnormality.
Function and Control
Refrigerant shortage zone
40 ~ 55 Hz Frequency
(depending on
the model)
(R11685)
Refrigerant shortage
zone
(R1391)
Control Specification
58