Purpose of vacuuming of automobile air-conditioning system Vacuuming of automobile air-conditioning system is to remove air and water vapor in the refrigeration system, which is an extremely important procedure in air-conditioning maintenance. When the car air conditioner is repaired or the components in the air conditioner refrigeration circuit are replaced, air may enter the system. There can be no air in the air conditioner refrigeration circuit, so the air must be completely extracted. How long does it take to vacuum the car air conditioner?
When vacuuming, as the pressure is getting lower and lower, the water gradually vaporizes into steam and is drawn out. This process is relatively slow, so vacuuming generally takes more than half an hour.
Vacuum pumping of automobile air-conditioning is generally used in conjunction with a vacuum pump and a pressure gauge of automobile air-conditioning manifold:
① Connect the high and low pressure hoses of the manifold pressure gauge to the high and low pressure side valve valves (blue, low, red, and high), and connect the middle hose to the vacuum pump.
② Open the high and low pressure manual valves on the manifold pressure gauge, start the vacuum pump, observe the pointer of the low pressure gauge, there should be a vacuum display.
③ After 5 minutes of continuous pumping, the low pressure should reach 30kPa, and the high pressure pointer should be lower than zero. If the pointer of the high pressure gauge is not lower than zero, it indicates that there is a blockage in the system. The vacuum should be stopped, and after repair, vacuum again.
④ After the vacuum pump works for 15 minutes, the pointer of the low pressure gauge should be 10-20kPa. If this value is not reached, close the high and low pressure manual valves and observe the pointer of the low pressure gauge. If the pointer rises, it means that there is a loss of vacuum and the system has leaks. The vacuum should be stopped and the vacuum can be continued after repair.
⑤ When the system pressure is close to vacuum, close the high and low pressure manual valves and keep the pressure for 5-10 minutes. If the pointer of the low pressure meter does not move, open the high and low pressure manual valves to turn on the vacuum pump and continue to vacuum. The vacuum time shall not be less than 30 minutes.
⑥ At the end of vacuuming, first close the high and low pressure manual valves, and then close the vacuum valve system, so that the system can be filled with refrigerating oil or refrigerant.
Car air conditioner vacuum step video
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