The role of transformer oil analysis in the detection of fault conditions

Summary form only given. The author emphasises the role which dissolved gas analysis continues to play, highlighting the clear cost benefit which can be achieved by a well managed diagnostic service on transformer oils. Examples are given of experiences where developing faults have been tracked by dissolved gas analysis, using both manual oil sampling and online techniques. An update is given of the use of furfuraldehyde in oil analysis for the detection of paper degradation in generator transformers. In the light of recent changes which have taken place in the arrangements for the testing of transformer oils within the UK electrical industry, the author emphasises the need to maintain continuity in the production of national and international standards. The status of the revision of IEC 567, the guide to sampling and analysis of oil and gas from transformers, is also reviewed. The author describes the need for a robust, low cost online gas analyser which could be permanently installed on a transformer, or preferably serve several transformers