This problem is not complicated, to ensure that all the connection pipes are normally connected, no air leakage, in the outdoor unit will be high and low pressure valves are fully opened with hex, remove the fluorine nozzle nut, connected to the vacuum pump, so that you can directly vacuum, not only the air in the compressor, the entire system of air is pumped clean, observe the pressure gauge pointer, generally pumped to 0 -30 can be, The time is about half an hour or so, after vacuuming, close the pressure gauge, connect the fluoridation tank, enter the air fluoridation pipe refrigerant to discharge the air, and then probably charge a small part of the refrigerant into it, slow 2-3 minutes, open the air conditioning to the forced refrigeration mode, you can arbitrarily disconnect a four-way valve line in the case of heating, card on the ammeter, Observe the running current and pressure while adding fluoride, and wait until the current reaches the rated value.