Principal failure cases on distribution switchgear using in the 22.9kV-y distribution system

The faults of the pole mounted switchgears and the pad mounted switchgears in the Korea Electric Power Corporation (KEPCO) distribution system that have occurred over the last one year have been analyzed. The result has shown that, in the case of the pole mounted switchgear, 40% of the faults were caused by the bushing part, and, in the case of the pad mounted switchgear, the breakdown of the internal insulators accounted for the 24% of the faults. This research paper will present the causes of the faults through detailed analyses with regard to the principal failure of the switchgears.