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Support
3 . Evacuation The system must be evacuated to remove moisture and noncondensable gases such as air . If a system is not evacuated properly the system will not give required performance . With HC refrigerants there is no need to evacuate the system for any longer than you would do for R134a . A system should be evacuated to 500 microns . Again , when you evacuate the system , work in a well-ventilated area or outside . Connect a line to the outlet of the vacuum pump and vent to a safe ventilated area . Use the wall socket switch and not the switch on the vacuum pump to turn your vacuum pump on and off .
4 . Charging Refrigerant should only be charged into a clean , dry , leak free system . You must evacuate the system before charging with refrigerant . When charging HC refrigerant you must not do any work with hydrocarbon refrigerants in confined spaces .
Make sure that :
• the charging area is very well-ventilated ( or outside )
• the charging equipment is suitable for use with HC refrigerants , that it is safe and accurate
• you vent as little refrigerant as possible into the air
• you have a dry powder type fire extinguisher in the charging area
NB : you can take charge from the cylinder in the liquid or gas state . ( Not applicable to blends ).
The area where you charge refrigerant into an appliance should be very well ventilated or outside . To be safe the charging area must :
• be a no-smoking area
• be at least 2m from flames and sparking electrical components
• never be below ground Do not store refrigerant in your charging area , hydrocarbons should be stored outside ( i . e . as LPG is stored ), under cover as previously described .
“ It is preferable to use dry , oxygen free nitrogen for pressure testing . Note – dry , oxygen free nitrogen is 99.997 % nitrogen . Testing pressure should be 1.3 times the working pressure .”
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RACA Journal I June 2023 www . refrigerationandaircon . co . za