Bushing for distribution transformer

Abstract

An electrical bushing for a transformer housing includes an elongate conductor with a metal annular disk for welded attachment to an edge of an aperture in the housing with an insulating bushing between the conductor and the disk. The insulating bushing includes first and second tubular bushing portions each formed of a cast epoxy resin and each surrounding a portion of the elongate conductor. the first bushing portion is cast on the elongate conductor with an integral bond therewith. The second bushing portion can slide along the exterior surface of the elongate conductor and is threaded onto a male portion of the first bushing portion. The first and second bushing portions have annular abutment surfaces clamping the annular disk therebetween and typically three sealing O-rings are provided at the junction to prevent passage of the transformer liquid from the interior.