Service manual
Troubleshooting - Outdoor Unit Related SiE18-201
244 Service Diagnosis
3.3.31 Operation Halt Due to Detection of Gas Shortage
Outdoor Unit
Indication
U0
Method of
Malfunction
Detection
Detection Method 1
Lack of gas is detected using the input current detected by the CT and the compressor's
operating frequency.
Detection Method 2
Lack of gas is detected using the discharge pipe temperature and the motorized valve opening.
Malfunction
Decision
Conditions
Detection Method 1
Input current < 0.09 ° Compressor's operating frequency -3.5
However, when the above state continued for 7 minutes with the operating frequency > 55(Hz)
Detection Method 2
discharge pipe temperature >Target discharge pipe temperature +20˚C, that should be
continued for 80 seconds or longer with motorized valve full opening.
Note: The target discharge pipe temperature is calculated with the microcomputer.
Supposed
Causes
Gas shortage due to refrigerant leak
Faulty gas shortage sensor
Input current drop due to faulty compression of the compressor
∗ Disconnection of thermistor (all thermistors)
∗ Faulty CT
Faulty, Disconnected motorized valve
Incorrect wiring, piping