Water in transformer (paper/oil)

The "Water in the transformer (paper and oil)" criticality is caused mainly by mechanisms resulting from external influences, with moisture entering from the atmosphere, and internal influences, resulting from the degradation mechanisms of solid and liquid insulators that generate water (hydrolysis of cellulose). Causes in relation to life cycle phases Causes of the "Water in the transformer (papers and oil)"Read more

Main regulatory references: IEC TR 62874:2015, “Guidance on the interpretation of carbon dioxide and 2-furfuraldehyde as markers of paper thermal degradation in insulating mineral oil” IEC 60422:2024, “Mineral insulating oils in electrical equipment – Supervision and maintenance guidance” CIGRE Technical Brochure 227, 2003 “Life Management Techniques for Power Transformer” CIGRE Brochure 323, 2007 “Ageing of cellulose in mineral-oil insulated transformers”Read more

Paper, kraft paper, insulating paper, cardboard/precompressed cardboardPaper (from IEC Electropedia) cellulosic paper of certain types, frequently characterised by their relatively high rigidity Note – In general the term paper is used for cellulosic papers if not otherwise specified. [source] Kraft paper  (from Wikipedia) Electrical insulation paper (from Wikipedia) (paper) board - pressboard (from IEC Electropedia) generic term applied to certain types ofRead more

Electrical insulation If the temperature drops the water migrates from oil to the papers and vice versa if the temperature rises In electrical transformers, insulation is mainly ensured by the oil and paper system. The construction of transformers provides for operational practices such as to guarantee a concentration of water in paper typically less than 0.5% -1% in mass, in relationRead more