SURFACE FLASHOVER CHARACTERISTICS OF EPOXY SPACERS IN COMPRESSED GASES.

The surface flashover characteristics of epoxy-resin cylindrical spacers in compressed air, gases like nitrogen and freon and gaseous mixtures like freon-air and freon-nitrogen are determined for plane-plane electrode and rod-plane electrode configurations and the spacer efficiencies for such electrode configurations are examined. It is found that the spacer efficiency in a plane-plane electrode system is less than one whereas in a rod-plane electrode system, it is greater than one. A comparative study of surface flashover characteristics of spacers in freon-air and freon-nitrogen gaseous mixtures brings out that freon-nitrogen gaseous mixture is superior to freon-air mixture. It is seen that the contamination in the form of conducting protrusion on the electrodes in a plane-plane electrode system has a profound effect on the flashover voltage of the spacers, whereas in the rod-plane electrode system, this effect is little noticeable.