Troubleshooting SiBE041134EB66 Service Diagnosis4.6 Refrigerant ShortageError Code U0Method of ErrorDetectionDetecting by discharge pipe temperatureRefrigerant shortage is detected by checking the discharge pipe temperature and the opening ofthe electronic expansion valve. If the refrigerant is short, the discharge pipe temperature tendsto rise.Detecting by the difference in temperatureRefrigerant shortage is detected by checking the difference between suction and dischargetemperature.Error DecisionConditionsDetecting by discharge pipe temperatureThe following conditions continue for 80 seconds. Opening of the electronic expansion valve ≥ D Discharge pipe temperature > E × target discharge pipe temperature + FDetecting by the difference in temperatureWhen the difference of the temperature is smaller than G°C, it is regarded as refrigerantshortage. If the error repeats, the system is shut down. Reset condition: Continuous run for about 60 minutes without any other errorSupposedCauses Disconnection of the discharge pipe thermistor, indoor or outdoor heat exchanger thermistor,room or outdoor temperature thermistor Closed stop valve Refrigerant shortage (refrigerant leakage) Poor compression performance of compressor Defective electronic expansion valveD (pulse) E (–) F (°C)480 128/128 30OperationmodeDescription G (°C)Cooling room thermistor temperature – indoor heat exchanger temperature 4.0outdoor heat exchanger temperature – outdoor temperature 4.0Heating indoor heat exchanger temperature – room thermistor temperature 3.0outdoor temperature – outdoor heat exchanger temperature 3.0
