An effective loss prevention method that ought to be included in every condition-based predictive maintenance program is transformer oil testing. Transformer oil, sometimes referred to as insulating oil, is a special kind of oil that has remarkable electrical shielding capabilities and remains stable at elevated temperatures. Oil-field electrical power transformers employ transformer oil to disperse the transformer, confine, and stop partial discharge and arcing (i.e., function as a cooling).
The liquid in the transformer is a component of the insulation system in addition to acting as a medium for heat transfer. As such, it makes sense to periodically test the oil to see if it is capable of fulfilling its function as an insulator. Screen tests, water content, metals-in-oil, polychlorinated biphenyl, and dissolved gas in oil analysis are a few of the most popular transformer oil tests.
Methods for Testing Transformer Oil are an essential component of any maintenance schedule. The most important test for the liquid lining is a yearly DGA. The transformer’s arcing, corona discharge, liquid overheating, and insulation overloading can all be identified by an analysis of the gases in the oil. Additional physical, chemical, and electrical tests, including as power factor, dielectric breakdown, acidity, color, and interfacial tension, are included in the screen test. No single test is able to accurately determine the liquid’s true height. As a result, it is essential to run each test. Additionally, transformer oil labs conduct essential tests for metals in oil, PCB furanic compounds, and water content.
When a transformer or other electrical distribution equipment is in use, it is subjected to mechanical and electrical strains. An essential component of an economical electrical maintenance program, insulating oil analysis not only yields information on the oil itself but also makes it possible to identify hidden flaws and other potential issues such contact arcing and aging insulating paper.
Following parameters of insulating oil or transformer oil should be considered to analyse the serviceability of oil.
The Furan and DGA tests are specifically not for determining the quality of transformer oil, but for determining any abnormalities in the internal winding of paper insulation of the transformer, which cannot be otherwise noticed without a complete analysis of the transformer.
