Retail Observer

MARCH 2016 RETAILOBSERVER.COM 95 Q: How does an HC system work? A: A system using hydrocarbons works in exactly the same way as systems currently using synthetic refrigerants. The basic refrigeration cycle remains the same, and only the charge of the system (exact amount of refrigerant) varies. WARNING: It is very unlikely that combustion will occur inside a sealed system, as there will be insufficient air. However, if the hydrocarbon refrigerant leaks out of the system, combustion can occur if the correct mixture exists and there is an ignition source. This is dangerous and must be avoided. WARNING: Servicing and repair of R-600a refrigerators should only be performed by skilled and well-trained service technicians. R-600a requires very careful handling because of the flammability of the gas, which is a potential danger during work on the refrigeration system. A well-ventilated room is necessary and there should be no open fl ame or combustion source within 6 feet of the work area, in case of accidental discharge. Note: The first big difference between R-600a and R-134a or R-12 is found in the system pressures, which operate at lower levels. This leads to operating pressures being very much lower than previous refrigerators utilizing R-12 or R-134a. Evaporators of R-600a refrigerators will operate well below normal atmospheric pressure, typically in a 5- to 18-inch vacuum. All R-600a leak–checking must be performed in open- air or a well-ventilated room, or the technicians could risk injury to themselves or others. Leak checking should be performed on a powered-off (equalized), sealed system. Bubble solution (WX05X10507) or equivalent is the approved leak detection method. Open- flame leak detectors are not recommended with hydrocarbon products. Some sniffer-type leak detectors work with hydrocarbons. Special detection equipment is available for use with hydrocarbon products. If in doubt, check with the leak detector manufacturer. Conversion of an R-12 or R-134a refrigerator to R-600a is not recommended because R-12 and R-134a appliances are not approved for fl ammable refrigerant use. Electrical safety in these units are not proven to acceptable safety standards. The normal risks a CFC or other toxic refrigerant would have when it escapes are mainly related to depletion of breathable air and frosting at the point of escape. Hydrocarbons have an explosion risk associated, also, (in addition to depletion of breathable air and frosting). Explosion risk is more dangerous directly to anyone in the vicinity, should it accumulate and come into contact with any ignition source. Basically, treat it as you would an LP gas or any other flammable vapor. More on this exciting new avenue for revenue is forthcoming in our Service Library and will also be added to our PSA Service Training Programs, such as Basic and Advanced Refrigeration. Once you have familiarized yourself with R-600a, you will be surprised how easy it can be to service. Classes will be held at our annual service convention in Dallas this year, so plan to attend! See you at NASC 2016! Jim Campbell, MCAP Professional Servicers Association RO

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