SiENBE07-618_C
Control Specification
Function and Control
41
3.12 Malfunctions
3.12.1 Sensor Malfunction Detection
Sensor malfunction may occur in the thermistor.
Relating to Thermistor Malfunction
1. Outdoor heat exchanger thermistor
2. Discharge pipe thermistor
3. Radiation fin thermistor
4. Outdoor temperature thermistor
Relating to CT Malfunction
When the output frequency is more than
Hz and the input current is below
A, it is judged
as malfunction.
3.12.2 Detection of Overcurrent and Overload
Outline
An excessive output current is detected and, the OL temperature is observed to protect the
compressor.
Detail
If the OL (compressor head) temperature exceeds about 120°C (depending on the model),
the system shuts down the compressor.
If the inverter current exceeds 20 A, the system shuts down the compressor.
3.12.3 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
refrigerant shortage.
Refer to “Refrigerant shortage” on page 90 for detail.
(Hz)
(A)
55
0.5
(Hz)
55
Frequency
Power consumption
Refrigerant shortage zone
Hz
(R11262)
(R1391)
Target discharge
pipe temperature
Refrigerant shortage
zone
SIENBE07-618_C_FRONT.pdf 53
9/02/2011 9:25:05
