A transformer bushing is an insulating structure that facilitates the passage of an energized, current-carrying conductor through the grounded tank of the transformer. The conductor may be built in to the bushing, i.e., a bottom-connected bushing, or the bushing may be built with the provision for a separate conductor to be drawn through its centre, a.k.a., a draw-lead or draw-rod bushing.
If I were to be asked “What one article or paper would you recommend as a knowledge building foundation for Transformer Bushings?”, the answer would be: "You are about to read it!" Corné Dames, one of our most gifted and significant Contributing Editors has done the research and come up with a great Feature Article for our bushings focus. Enjoy another important contribution from Corne, a great participating member of our TT community. Thank you so much Corne; you are an inspiration to us all.
The Bushing of power transformer is a type of porcelain or ebonite post insulator put on the top or side of the transformer tank through which connections are made to the external circuit.
As bushing is a self contained unit, as such there is no specific maintenance to be carried out. However , a periodical check of the oil level and cleaning of the porcelain will normally be sufficient