Characteristics of Artificially Contaminated Metal Oxide Surge Arresters by Equivalent Fog Method and Fog Method

摘要

The artificial contamination test of a zinc oxide lightning arrester was conducted using a simple equivalent fog test because the fog test facility was not available to the manufacturer. On one hand, the zinc oxide lightning arrester no longer requires series gaps because of the outstanding nonlinear resistance characteristics of the element. Accordingly, it is said to be superior in contamination proof characteristics. It is also said that washing live lines of insulating tubes is possible. Yet, when the outer surface of the insulating tubes of the zinc oxide lightning arrester is contaminated, uneven distribution of electric potential on the surface of the insulating tubes could cause high electric current to flow into local elements resulting in raised temperature of the elements. This could cause the phenomenon known as thermal runaway. This report attempts to solve the above question by testing the zinc oxide lightning arrester in both the equivalent fog test and the fog test and by attempting a quantitative comparison of the two test methods for the purpose of revealing the true nature of contamination of the tested lightning arrester. (ERA citation 10:031820)