Air Conditioner Vacuum Operation Procedures

  1. Check before operation:

  • The vacuum pump switch is off.

  • When the vacuum pump is placed horizontally, make sure that the lubricating oil is level with the oil level line.

  • Whether the sealing rubber gasket is damaged.

  • Whether the needle of the pressure gauge is reset to zero.


  1. Place the vacuum pump on the indoor floor (a safe, stable and easy-to-operate place). It is not allowed to be placed outdoors, let alone placed on the outdoor unit of the air conditioner.


  1. Combine the fluoride tube, pressure gauge and vacuum pump together.


  1. Unscrew the nut at the fluoride port from the large valve, screw the fluoride tube onto the fluoride port, and confirm whether the thimble is in place. (It is forbidden to use tools such as pliers to tighten the joints.)


  1. Open the pressure gauge valve first, then turn on the vacuum pump power switch to start vacuuming.


  1. Vacuuming: Observe the pressure gauge (low pressure), and stop vacuuming after the pressure reaches -0.1 MPa (negative pressure). The vacuuming time should be determined according to the model and the size of the vacuum pump. The recommended time is 10-30 minutes, and the minimum is no less 5 minutes, and should be based on the pressure value displayed on the pressure gauge.


  1. Turn off the pressure gauge valve first, and then turn off the vacuum pump power switch.


  1. Remove the fluoride tube from the vacuum pump, and tighten the cap of the vacuum pump inlet nozzle to prevent dust from entering. After vacuuming, the pressure must be maintained before leak detection. If the pressure is higher than -0.08 MPa, the cause of the leakage must be found.


  1. Confirm that the pressure is not higher than -0.08 MPa (a small rebound of 0.02 MPa pressure is allowed) before operating the subsequent procedures. If the pressure is higher than -0.08 MPa, it indicates that there is a leak, user must find the cause of the leak and repeat the above process after solving it.


  1. After confirming that there are no leaks, open the small valve, and close the small valve when the pressure (low pressure) reaches 0.1 MPa-0.5 MPa. At this time, if the pointer of the pressure gauge does not move, user need to slightly open the pressure gauge valve to see if there is gas discharge. If no gas discharged, the vacuum operation should be performed again (starting from the fourth step).


  1. After confirming that the evacuation operation is over, quickly remove the fluoride pipe and pressure gauge, and then fully open the small valve and turn it for a half turn.


  1. Fully open the large valve and turn it half a turn, and immediately tighten the valve back cover nut to prevent leakage of the rubber sealing ring, and at the same time tighten the fluorine-filled nozzle nut.

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