Troubleshooting for Outdoor Unit (50/60 class) Si21-205214 Troubleshooting7.13 Insufficient GasRemoteControllerDisplayU0Method ofMalfunctionDetectionGas shortage detection I : A gas shortage is detected by checking the CT-detected input currentvalue and the compressor running frequency.Gas shortage detection II : A gas shortage is detected by checking the difference betweenindoor unit heat exchanger temperature and room temperature as well as the differencebetween outdoor unit heat exchanger temperature and room temperature.MalfunctionDecisionConditionsGas shortage detection I :Input current < (A/Hz) x Compressor running frequency × Voltage +However, when the status of running frequency > 55 (Hz) is kept on for a certain time.Note : The values are different from model to model.Gas shortage detection II :If a gas shortage error takes place 4 times successively, the system will be shut down. The errorcounter will reset itself if this or any other error does not occur during the following 60-minutecompressor running time (total time).SupposedCauses Refrigerant shortage (refrigerant leakage) Poor compression performance of compressor Discharge pipe thermistor disconnected, or indoor unit or outdoor unit heat exchangerthermistor disconnected, room or outside air temperature thermistor disconnected Stop valve closed Electronic expansion valve defectiveR410A 1756 / 256 –50
