摘要 |
Methods and apparatus for evacuating and charging a refrigeration unit having a compressor; a condenser; a receiver; an evaporator; hot gas, liquid and suction lines; and suction, discharge and liquid line service valves each having a service port position. A vacuum pump is provided which has first, second and third vacuum hoses respectively connected to the suction, discharge and liquid line service valves, with each vacuum hose having a controllable valve. Refrigerant supply apparatus is provided which is connected to the liquid line service valve. A method includes the steps of actuating the suction, discharge and liquid line service valves to open their service port positions, opening the controllable valves associated with the first, second and third vacuum hoses, operating the vacuum pump to provide a predetermined vacuum in the refrigeration unit via the first, second and third vacuum hoses, closing the controllable valves associated with the first, second and third vacuum hoses, charging the refrigeration unit via the liquid line service valve with refrigerant from the refrigerant supply apparatus, actuating the suction, discharge and liquid line service valves to close their service port positions, and removing the first, second and third vacuum hoses and refrigerant supply means from the suction, discharge and liquid line service valves. The apparatus includes means connecting the refrigerant supply apparatus to the third vacuum hose.
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