The quality requirements of transformer oil are very high, and it is difficult to determine whether the oil is qualified without withstand voltage test and chemical test, but unqualified oil can generally be identified from the appearance.

1) Color of oil: The color of normal oil is slightly yellow. If the color of the oil changes to reddish-brown or even black, it should be suspected that the oil has deteriorated, and the oil should be sampled for testing;

2) Transparency: The new oil is transparent in the glass bottle and has blue-violet fluorescence. If the fluorescence and transparency are lost, it means that the oil contains mechanical impurities and free carbon;

3) Odor: The transformer oil that has not deteriorated has no odor, or has a little kerosene smell. For example: burnt smell – the oil temperature is too high; sour smell – the oil is severely aged; acetylene smell – an arc is generated from the inside; other odors – produced by the reaction with the container.

For more information about oil-immersed transformer oil, you can check this article: What is the role of oil-immersed transformer oil


Determination of transformer oil quality

Post time: Jan-20-2022