Older oil filled electrical switchgear: past, present and future

Oil filled electrical switchgear has been in use both at high and low voltage for many years and has, of necessity, been of robust construction. This fact has led many to assume that it has an indefinite service life. There have been cases of high voltage switchgear installed 70 to 80 years ago still being in service. It is not uncommon to find both high and low voltage switchgear from the 1920´s and 1930´s still in use. Performance requirements for switchgear have risen over the years and switchgear technology has developed to meet the challenges. System fault energy levels have tended to increase as distribution networks have expanded to meet the ever increasing demands for energy. This has partially lead to the required improvements for the performance aspects of switchgear. Other improvements have arisen from operational needs. The author looks at some of the problem areas, the present position, and the future