The Development of an Oil-Immersed Surge Arrester for Distribution Transformers

The recent development of an oil- immersed, zinc oxide surge arrester meets a need for distribution transformer protection that is immune to environmental factors that frequently cause premature failure of conventional external arresters. This paper describes the design philosophy used to determine the requirements for this device and the tests performed to assure that they were satisfactory. Also discussed are benefits that this unique arrester provides in the form of improved reliability and cost effective surge protection of overhead and underground power distribution systems.