Hollow core composite bushings

摘要

An improved hollow core composite bushing for use in, for example, a dead tank circuit breaker, is smaller and lighter and offers other advantages over previous designs. The hollow core bushing includes therein a fiber reinforced plastic (FRP) elongated tube that operates to increase the dielectric constant between a conductor and a transition shield. By placing the transition shield external to the hollow core bushing and providing the FRP tube between the conductor and transition shield, the dielectric constant between the shield and conductor is increased thus allowing the inner diameter of the shield and outer diameter of the bushing to be decreased. In addition, the transition shield may be an integral part of the flange that is mounted to the bushing current transformer support column or interrupter enclosure of the dead tank circuit breaker thus further reducing the diameter and overall size of the bushing. Further, the transition shield may be an integral part of the FRP tube.