Research on anatomical observation and ablation conditions of vacuum interrupter with different service years

Vacuum interrupter(VI) is the most important part of vacuum circuit breaker(VCB). In this paper, interrupters with different fabrication technology which have been in service for several years were anatomized. The difference of shield case in the interrupters under different fabrication technology, wear phenomenon and arc erosion on contact plate were observed. Based on physical-chemical analysis, the influence of high current arcing on micro appearance of surfaces of contact plate and material composition of erosion area were studied. Scanning electron microscope combining with energy depressive spectroscopy was used to observe the surface morphology of contact plate after large current interrupting tests, and was analyzed the composition content in serious erosion area of contact plate. The results showed that after several operating years there was a melted layer exceeded 100μm thick and copper element of superficial zone was concaved down due to evaporation. Then, ingredient of attachment on shielding case and bellow were analyzed, and comparison of energy spectrum analysis between stainless bellow and brown spot on stain bellow was studied.