Automatic disconnector: Influence on the performance of medium voltage arresters and a new design proposal

Abstract This paper discusses the modes of actuation and misoperation of the automatic disconnector of distribution surge arresters. Taking into account the laboratory test results and field data search campaigns, the main problems concerning the operation of these devices and how it affects the reliability of the surge protection of transformers are discussed. In general, the misoperation of the disconnector is a design problem, concerning materials and production quality control. Considering this, a new design is also proposed, trying to avoid the main operation problems, resulting in a more simple and reliable device.