Low-voltage varistors quality testing

Abstract

Varistors are popular surge arrestors which protect the electronic equipment against damage caused by transient state voltage in the power supply lines. Therefore, their quality is important to effectively protect the equipment. Varistors are produced from inexpensive and popular material - zinc oxide with some additives, decisive of their quality and kept secret by the producers. The produced elements are tested at final stage of their production by checking their voltage-current characteristics. Unfortunately, during their operation and exposition various factors (humidity, high currents conduction) degrade their protective properties. Consequently, varistor can lose valuable features and their protecting role. Thus, it is necessary to test efficiency of varistors? protective role applied in low-voltage power lines. This paper presents microscopic varistor structure and describes processes which diminish their electrical properties. Additionally, it presents some methods of varistors? quality testing.

Keywords

varistors quality testing, surge arrestor, voltage-current characteristics, SiC

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Bilbiography

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