A comparative program on HVDC contamination tests

The reproducibility of artificial contamination tests for insulators energized with HVDC is investigated in a series of comparative tests performed at two different laboratories using clean fog and predeposited contaminants. The effects of fog generation, type of inert material, single vs. multiple string test configurations, and characteristics of the power supply are reported. The controls required to achieve reproducible results are defined for tests on ceramic insulators, and the limitations in applying these controls to tests on nonceramic insulators are described. >