Mechanical life is the main evaluation index for the product quality of high-voltage vacuum circuit breakers. According to relevant data reports, the National High-voltage Electrical Appliance Quality Inspection Center has conducted 6 times (1993, 1995, 1996, 1999, 2002 and 2003) supervision and spot checks on domestic high-voltage vacuum circuit breakers, and the pass rates are 83.3%, 91.3%, 58.8%,60%, 57.1% and 78.6% respectively, one of the main problems is that the mechanical life cannot reach the specified value of the enterprise standard, and the main parameters of the mechanical characteristics also exceed the specified range of the product technical conditions.
Usually a 10kv high-voltage circuit breaker is composed of hundreds of parts, and the processing and process defects of each part, as well as the mutual connection, will directly affect the mechanical characteristics of the high-voltage circuit breaker. At the same time, most of the auxiliary switches, micro switches, reducers, terminals, etc. that are matched with the operating mechanism are external components, which have a certain degree of dispersion, and the quality is difficult to achieve 100% pass rate. These problems are directly The main factors affecting the mechanical life of vacuum circuit breakers. Some vacuum circuit breakers have a nominal mechanical life of 30,000 times, and some even reach 60,000 times or 100,000 times. Therefore, in the selection and application of high-voltage vacuum circuit breakers, it is not advisable to believe the false words of the product manual, and the actual test report should be used as the basis. If it can operate safely and reliably 20,000 times, it is enough to meet the application requirements of the operation site. .
