Water Droplets on Polymeric Surfaces Under the Influence of Uniform Electric Fields: An Investigation with Horizontal and Inclined Test Electrode Arrangements

In this paper, the problems arising from the application of uniform ac electric fields on water droplets, which are on polymer surfaces, are investigated. Polymeric materials such as silicone rubber, PVC and rubber were used. Two test arrangements were used, one being horizontal, the other being inclined. The deterioration phenomena and localized arcs were studied in terms of water conductivity, polymer surface roughness, droplet volume and droplet position w.r.t. the electrodes. Tests were carried out with water conductivities covering a wide range of values. All mentioned parameters affect the flashover voltage. The degree of the importance of each of them, however, varies. A significant point of this work is that, for both the horizontal and the inclined test arrangements, the positioning of the droplets plays, at least in some cases, a greater role in determining the flashover voltage than the droplet volume.