The invention in a first aspect relates to an improved cast resin bushing assembly for use in a transformer wherein the bushing assembly comprises: a bushing (11) which bushing includes locating means for aligning the bushing assembly within a transformer casing (16); wherein the bushing further includes a locking means for releasably securing the bushing assembly to a transformer casing (16); a bushing conductor (15); and a bushing flange (7) in circumferential arrangement with the bushing (11). In a second aspect the invention relates to a method of securing an improved cast resin bushing assembly to a transformer casing (16) which bushing assembly comprises: a bushing (11) which bushing includes a locating means for aligning the bushing assembly within a transformer casing (16); the bushing (11) further includes a locking means for releasably securing the bushing assembly to a transformer casing (16); a bushing conductor (15); and a bushing flange (7) in circumferential arrangement to the bushing (11); wherein the transformer casing (16) has an opening adapted to receive the bushing assembly or part thereof; and the bushing flange (7) is mounted on the outside of the transformer casing (16) and secured thereto by engaging the locking means on the inside of the transformer casing (16).
