The durability and performance of polymer housed metal oxide surge arresters under impulse current stresses

Even very stringent environmental factors may stress metal oxide surge arresters (MOAs) during their fairly long desired life time (20 – 50a). For example, a large number of impulses, ambient humidity and rain will cause remarkable stresses on MOAs especially in regions of high lightning activity. Detailed data on the effects of different stresses on MOA performance are difficult to obtain from field experiences because these experiences are often based on failure cases and failed arresters are normally burned with power arcs to such a condition that only general assumptions of the initial reason of the failure can be made. Either exhaustive laboratory tests or instrumentation of arresters in field service is needed to gather thorough information.