Electric breakdown of perfluorocarbon vapors and their mixtures with nitrogen

This investigation was concerned with a study of the breakdown behavior of the higher molecular weight perfluorocarbon vapors and mixtures of these with nitrogen. Impulse and 60-cycle data were obtained under both uniform and nonuniform field conditions. The results are compared with those for sulfur hexafluoride, nitrogen, and oil. It was found that these perfluorocarbon vapors have surprisingly high dielectric strength not only in the pure form but also when mixed with nitrogen. Values of dielectric strength higher than for sulfur hexafluoride are easily obtainable at the same pressure. Values equal to those for oil can be obtained at relatively low pressures under certain conditions. The results are briefly discussed in terms of modern gas breakdown theory. The unusually high dielectric breakdown combined with complete non-flammability, inertness, and excellent thermal stability of the perfluorocarbons suggest that they should find applications in the insulation field.