Abstract. The electrical breakdown of dielectric liquids is considered from the viewpoint that known breakdown mechanisms in liquids should be helpful in predicting breakdown mechanisms occurring in amorphous plastics. The effect on the breakdown process of increasing liquid viscosity is charted for both positive and negative discharges. It is in the short pulse positive discharge mechanism that the greatest similarities can be expected. Similarities are also noted in negative discharge processes for some solids and liquids of very high viscosity (100000 cS). The high effective viscosity of the plastics allows for the mechanism of cumulative (multi-pulse) damage which is not generally available in the liquids. However, experiments with liquids of viscosities only one or two orders of magnitude greater than the largest (100000 cS) reported for this paper should allow a valuable comparison in this area also.

Print publication: Issue 1 (14 January 1991)