(1) The gas pipe valve is dry, and there is no obvious cool feeling when touched by hand. The reason is that the lack of refrigerant leads to the advance of boiling endpoints in the evaporator, which increases the superheat of the refrigerant and the temperature of the valve, which is greater than the dew point temperature of the outdoor air.
(2) liquid pipe valve frosting. The reason is that the lack of refrigerant causes the pressure in the liquid tube to drop, the boiling point to decrease, so that the valve temperature is below freezing point.
(3) Open the panel of the indoor machine and take off the filter. It can be found that part of the evaporator dews or frosts. The reason is that due to the lack of refrigerant, only part of the evaporator has boiling heat absorption, so that the refrigeration area is reduced accordingly;
The outdoor unit exhaust air has no heat sensation. The reason is that the insufficient refrigerant reduces the condensing pressure, condensing temperature, and exhaust air temperature.
The drainage hose drains intermittently or does not drain at all. The reason is that the cooling area of evaporator decreases, the condensation area also decreases, and the condensation water decreases.
The outdoor unit gas, liquid valve oil, oil leakage. The reason is that refrigerant and frozen oil have a certain mutual solubility, fluorine escapes from the leak point into the atmosphere, and the oil adheres to the leak point around.
⑦ Measuring the working current of air conditioners is less than the rated current. The reason is that the refrigerant is insufficient to reduce the working load of the compressor and the current drops.
The pressure measured from the outdoor unit fluorine filling port is less than 0.45mpa. The reason is that the lack of refrigerant leads to a drop in evaporation pressure.
