Design of Zinc Oxide Transmission Line Arresters for Application on 138 kV Towers

Experimental zinc oxide strut arresters with series air gaps have been developed to protect transmission line insulator strings from lightnilng flashover. These arresters were designed for installation on existing 138 kV lines. The strut configuration of the arresters provides a demonstration of the feasibility of line voltage uprating by maintaining conductor-to-tower clearances in high wind conditions. Many special demands not imposed on high voltage arresters for substations have been considered and addressed. This paper summarizes the application principles for transmission line arresters, describes tests which were performed on the devel opmental arresters and gives operati ng characteristics of arresters constructed for an experimental field testing program.