Breakdown voltages of various air gaps in the presence of dielectric sheets (barriers)

AC breakdown voltage tests were conducted in air to measure the performance of small gaps (up to 0.2 m) formed by an energized and a grounded electrode with a dielectric sheet between them. Rod-rod and conductor-rod electrodes were used for the experiments. In order to simulate live-line maintenance conditions, a typical solid and a stranded conductor, used by electric utility companies, were employed for the conductor-rod tests. Qualitative and quantitative results of the test series show how the breakdown voltage varies with the type of electrodes, the distance between the them, the material and size of the barrier, and with the relative position of the electrodes and the barrier between them.