The European Standard concerned with the safety of domestic refrigerators is EN 60335-2-24:2001 "Safety of household and similar appliances-Part 2-24: Particular requirements for refrigerators, food freezers and icemakers". [1] (The Standard). A domestic refrigerator with a flammable refrigerant (R600a) was tested according to the methods specified in the Standard. Some of the test specifications were reproducible but some were ambiguous and gave different results depending on the methodology used. This paper describes the reasons for the test specifications in the Standard concerned with the use of flammable refrigerates (in so far as they are clear) and the tests that could give different results depending on how the test methods were interpreted. The method of testing the protection of the refrigeration circuit against mechanical damage did not simulate the type of damage that could be caused by defrosting the evaporator with a knife. The simulation of a leak in a protected cooling circuit was not specifically defined. The concentration of refrigerant in the compartment with a protected circuit depended on the method used to simulate the leak (either 140ppm or 17,500ppm). The position and direction of a simulated leak in the compressor compartment was not specified in the Standard but had a significant effect on the concentration distribution in the compressor compartment (643 to 240,000 ppm). The sudden release of an accumulation of refrigerant in a compartment caused peaks in the concentration of refrigerant around electrical components that could not be measured by the response time of the measuring instrument specified.
展开▼
