(1) After checking that it is airtight, discharge the nitrogen gas.
Connect a pressure gauge to the service ports on the liquid side, on the gas side, on the balance side, and connect a vacuum pump as directed by the manufacturer. Make sure to perform the vacuum on the liquid, gas and balance sides.
(2) Use a vacuum pump with large displacement so that the vacuum level becomes less than - 755mmHg.
(3) Run the vacuum for 2 or 3 hours, although the time is different due to the length of the tubes.
This time, check that all regulating valves on the liquid, gas and balance sides are fully closed.
(4) If the vacuum level does not reach –755mmHg or less, even after running it for two or more hours, run the vacuum for 1 hour or even longer. If the vacuum level does not reach –755mmHg even after 3 hours or more, check the position of the leak.
(5) When the vacuum level reaches - 755mmHg or less after 2 hours or more, fully close the pressure gauge's VL and VH valves, stop the vacuum pump, leave it as it is for an hour, and then check that the degree of vacuum has not changed. If it changes, there may be a leak position. Check the position of the leak.
(6) After the vacuum procedure is complete, replace the vacuum pump with the refrigerant cylinder and proceed to the additional refrigerant charge work.
(7) After evacuating the system, replace the vacuum pump with a refrigerant cylinder and fill the system with additional refrigerant.
When the system is filled with refrigerant at the factory, the additional quantity on site is not included. Calculate the additional amount needed and add it to the system.
