OUTDOOR INSULATORS AND HOUSINGS BREAKDOWNS CAUSED BY POLLUTION

A heavy pollution on outdoor insulators causes electrical discharges, flashovers, surface erosion or tracking. In extremely cases the dielectric breakdowns occur. In this paper the breakdowns of four insulators has been shown: porcelain bushing insulators on rectifier set ups of electrostatic precipitators, the porcelain fuse cutouts, a porcelain housing of metal oxide surge arrester and polymer concrete insulators. The analysis of other damages of condenser bushings and instrument transformers published in the literature has led us to a hypothesis that a part of these failures could be initiated or accelerated by external pollution