Lifetime evaluation of EVA insulator for distribution system by accelerated salt-fog test

In this paper, the insulation performance of 22 kV class EVA insulator was studied through comparing the leakage current obtained from the field test and the accelerated multi-stress test (EdF´s test). However, 5000 hours, the test time of EdF´s test, is quite long, so the salt-fog ageing test of short term is used in this experiment, which also can evaluate the insulation performance of polymeric insulators effectively. In this study, 13.3 kV_rms AC voltage was applied during the 500-hour salt-fog ageing test. The conductivities of salt-fog were 8 mS/cm, 16 mS/cm and 800 μS/cm, respectively and the different accelerated factor in each case as determined. As a result, the leakage current over 10 mA was observed in the heavy rain condition of, as same was the real service condition.