A diagnosis of remaining life characteristics of ZnO type surge arresters (1/sup st/ stage) for 275 kV power systems

Zinc oxide surge arresters have been developed and widely used in the world, about 25 years have been passed from the first applications to the actual fields. It is important to presume remaining performance characteristics of these ZnO type surge arresters. In order to evaluate these remaining life characteristics, accelerated aging tests and stability tests have been performed by using the 1/sup st/ stage ZnO elements for 275 kV power systems after about twenty years experience on the actual field in Japan. This paper describes of remaining life characteristics of the 1/sup st/ stage ZnO elements for gapless zinc oxide surge arresters.