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AIR CONDITIONING 7 . The low side gauge should indicate a vacuum Sweeping of 660 mm Hg within five minutes. 8. Whilst the system is evacuating, fill the NOTE: This operation is in addition to charging cylinder by opening the refrigerant evacuating, and is to remove moisture from drum valve. systems that have been open to atmosphere for 9. Open the valve at the base of the charging a long period, or that are known to contain cylinder and fill the cylinder with 1,0 kg of excessive moisture. refrigerant. Liquid refrigerant will be observed 1. Fit a new liquid receiver/drier, as detailed open the valve at the top of the cylinder 2. Ensure that a full drum of refrigerant is fitted (behind the control panel) intermittently, to on the charging and testing equipment. relieve the head pressure and allow the 3. Fit the charging and testing equipment as refrigerant to continue filling the cylinder. previously described for evacuating and 11. When the refrigerant reaches the desired level evacuate the air conditioning system, allowing in the sight glass, close both the valve at the 0,25 to 0,45 kg of refrigerant to enter the base of the cylinder and the valve at the charging cylinder. bottom of the refrigerant tank. 4. Close all valves on the charging and testing 12. Ensure the top cylinder valve is fully closed. If equipment. bubbling is present in the sight glass, reopen 5. Disconnect the intake hose from the vacuum equalise the drum and cylinder pressures. 13. If 660 mm Hg of vacuum is not achieved within five minutes, it signifies either the system has a leak or the vacuum pump is defective. Initially check the vacuum pump, if to be functioning properly then investigate for a leak in the air 14. Close the vacuum control valve No. 3. 15. Stop the vacuum pump and allow the vacuum to hold for fifteen minutes, then check that loss of vacuum) evident on the compound gauge. Any to the heading titled ’Leak Detection’ later in this 16. With the system satisfactorily evacuated, the system is ready for charging with refrigerant. 10. As the refrigerant stops filling the cylinder, under the heading “Receiver/Drier”. the cylinder base valve momentarily to pump. 6. Connect the intake hose to the valve at the top of the charging cylinder. 7 . Open the valve at the top of the charging 8. Put on safety goggles. No. 3 and allow some refrigerant to purge the 10. Open the high pressure valve (No.2). Slowly open valve No. 3, which is now connected to the top valve of the charging to flow into the system until the reading on the compound gauge 12. Allow the dry refrigerant introduced into the system to remain for 10 minutes. 14 REISSUED: FEB 1993 |