Retrofilling conditions of high voltage transformers

Abstract

This article reports the procedures and preliminary tests related to the retrofilling of a perchlorethylene-base d fluid (Transclene/sup TM/) filled transformer. Two insulating liquids, a mineral oil and an ester liquid that seemed to be suitable for this retrofilling, were investigated, In order to examine long-term effects, the investigations were performed on new samples as well as on samples subjected to severe ageing conditions. To simulate real operating conditions, the temperature was varied between O and 100 /spl deg/C with different water contents.