1.Current method:Use a clamp ammeter to monitor the actual current of the outdoor unit(including compressor and fan currents).If the current value is approximately consistent with the nominal rated current on the nameplate,it is proven that the refrigerant is suitable.If there are too many cases below the rated value,and the refrigerant is too low,it needs to be added.
　　2.Gauge pressure method:The low pressure side pressure of a refrigeration system is related to the amount of refrigerant.The low pressure valve is connected to a pressure gauge.When the air conditioner starts to cool,the gauge pressure drops.After operating for more than 10 minutes,the gauge pressure stabilizes at about 0.49 mpa,which can be normal.
　　3.Attention:Pay attention to the condensation of the high-pressure pipe near the high-pressure valve of the outdoor unit and the low-pressure pipe near the low-pressure valve.Usually,the high-pressure pipe condenses and is very cold.After condensation on the low-pressure pipe,it will have a refreshing feeling,and the temperature is about 3℃higher than that of the high-pressure pipe,proving that the refrigerant is suitable.If the low pressure pipe does not condense and there is a temperature sensation,it is necessary to prove that the cooling dose is insufficient and add.Low-pressure pipe condensation occurs every 1 minute or so after the compressor is started,which proves that there is too much refrigerant and it must fall off slightly.