Household Unit Technical Service Manual
41
(1) Discharge the high pressure nitrogen which is used for leakage detection.
(2) Connect the pressure gauge to the Freon nozzle on both the high-pressure valve and low-pressure
valve of the system. In the two gauges, at least one must be low pressure gauge. The vacuum level
shall be based on the reading of low pressure gauge.
(3) Start the vacuum pump.
(4) After the vacuum level reaches -1.0kgf/cm
2
, continue to vacuumize for 0.5~1.0 hour. Then, stop the
vacuum pump.
(5) Change the hose, which is connected to the vacuum pump, to the Freon tank (Always use the
refrigerant marked on the nameplate). Discharge the air in the hose and charge Freon into the
system pipeline, until the pressure reaches 0.0kgf/cm
2
.
(6) Change the hose, which is connected to the Freon tank, to the vacuum pump. Start the vacuum
pump to vacuumize for 30 minutes, until the vacuum level reaches -1.0kgf/cm
2
.
4.5.5 Determination of Refrigerant Charge after Repair
As gas charge is usually adopted for repair charge, it is basically impossible to ensure the mass flow
correctly. Therefore, it is required to charge the refrigerant slowly in reference to the charge volume on the
nameplate, ambient temperature and operating pressure, until the system has basically met the
requirements.
