| Leakage accident occurred occasionally with electricity entering into the life. Leakagecircuit breaker, a common breaker in the low-voltage circuit, plays an important role inpreventing electrical shock and leakage accident. It not only has certain economic benefits, butalso has a wide range of social benefits as it’s an electrical appliance which relates to people’slives and property safety.The reliability and failure mechanism of leakage circuit breaker is studied in this paper.National Institute Standards GB/Z22202-2008,"Reliability test methods of residual currentoperated circuit breakers for household and similar purposes†is selected as basis of this paper.Operating failure rate test, instantaneous protection success rate test and residual currentprotection success rate test have been finished according to test conditions, test methods andfailure criteria for leakage protection reliability tests provided by this national standard. Besidethese, the EMC test has been finished, because malfunction occurs during test, to confirmfailure cause. Research about influence of temperature, humidity and vibration on failuresamples is done after analyzing test result, so does the unbalanced zero sequence currenttransformer influence and the over-voltage and electromagnetic interference influence. In theend of this paper, improvements such as painting conformal coating on circuit board uniformly,improving assembly technology and quality of zero-sequence transformer balance, and makingcircuit board better are suggested. |
