The gas pressure in the temperature sensing package of mechanical thermostat with temperature failure changes with the temperature change, which drives the contact of thermostat to act. Due to contact adhesion, insufficient spring elasticity and other reasons, the contacts are normally closed, and the air conditioner is continuously turned on, resulting in icing. Replace the thermostat, troubleshooting also has special circumstances, the thermostat is not damaged and the air conditioner is temporarily stopped or not stopped. Because the temperature sensor is hung in the middle of the evaporator with a U-shaped plastic frame, about 2mm away from the fins. It is estimated that the manufacturer's design is to make the temperature sensor of the thermostat play the role of temperature delay to prevent the air conditioner from starting frequently in a short time (within 3 minutes). In midsummer, the indoor temperature is high. Due to the limitation of air conditioning refrigeration, it is difficult for the thermostat to reach the temperature control breakpoint, and the air conditioner has a short downtime or even continuous start, which leads to icing. Most of this ice freezes at the lower part of the evaporator. In this case, it is necessary to move the temperature sensor to the lower end of the evaporator and fix it near the evaporator fin, so that the fault can be eliminated.
If the air conditioning system freezes, it may be that the air conditioning drain hole is blocked, the water content of the air conditioning refrigerant is too high, and the temperature sensor is faulty. Drivers need to find a professional to check the cause of the fault and then correct the fault.
Automobile air conditioner is a very important comfort configuration in automobile, which can cool and heat.
I think the refrigeration principle of automobile air conditioner is very simple. When automobile air conditioner is cooling, it is necessary to press the ac button, the compressor clutch will be engaged, and the engine will drive the compressor to rotate.
When the compressor rotates, it continuously compresses the refrigerant and delivers it to the evaporation box. The refrigerant expands in the evaporation box and absorbs heat, so that the refrigerant can cool the evaporation box. Cooling the evaporation box can cool the wind from the blower and make the air conditioner outlet blow out cold air.
When the air conditioner is heating, after the warm air function is turned on, the high-temperature antifreeze in the engine will flow through the warm air groove, and the wind blown by the blower will also pass through the warm air groove, so that the air conditioner outlet will blow warm air.
Most refrigerants used in automobile air conditioners are r 134a, which need to be replaced regularly, otherwise it will affect the refrigeration effect and speed of air conditioners.
When replacing the refrigerant, you need to go to a professional store and use professional equipment to replace it. Your friends can't change themselves.