Occurence and measurement of surface charges in the interrupter units of high-voltage circuit-breakers

All kinds of electrical plant and equipment incorporate parts made of insulating materials that can become electrically charged. It is actually undesirable for the equipment to pick up such charges because they can bring about a reduction in the dielectric strength of the material. This charging is well-known to occur in connection with the post insulators used in sulphur hexafluoride (SF/sub 6/) gas-insulated switchgear. The intention in this report is to extend investigations to the insulating material parts incorporated in the interrupter units of SF/sub 6/ high-voltage circuit-breakers.