Pollution performance of 110 kV metal oxide arresters

Pollution test results of single-unit 110 kV metal oxide surge arresters with porcelain housing according to the solid layer and salt fog methods are presented. During 6 hours of testing, the internal and external charge and maximum temperature along the varistor column were measured. The formation of single stable dry bands on the housing was often observed especially during salt fog tests. In such cases, the varistor temperature can reach about 70/spl deg/C. The simple electrical model of the arrester enabling calculations of voltages and currents as a function of arrester and pollution parameters is shown.