Analysis and suggestions of several malfunctions based on SF6 GIS facilities in capital construction or operation

SF6 electrical facilities malfunction contains these types: Forced fault (discharging channels mostly related to solid insulation, electric insulation cannot recover after high-energy discharge) and flexible fault (discharging channels mostly related to SF6 gas insulation or the combination of gas insulation and solid insulation, electric insulation recovers after high-energy discharge). Character of SF6 electrical facilities malfunctions can be determined by means of SO2 and H2S fast-local-detection. This essay expatiate on SF6 electrical facilities discharging malfunctions, including estimation evidence, type, part, and discharging current. Through conventional and unconventional chemical, electrical test instruments, through investigation on solid powder, gas composition and chemical materials in GIS SF6 CT gas chamber before and after the flashover fault, it comes to the conclusion that inner CT with frequent flashover fault contains nitrile butadiene rubber board. The corrosive sulfur reacting with the contact part plating silver produces silver sulfide. It forms the discharging channel finally, which causes the arc-over in the CT chamber.