Transformer oil can be divided into 15 colors. The colors are white, light yellow, light yellow, yellow, dark yellow, orange, light orange, dark orange, orange, light brown, brown, brown, brown. In addition, transformer oil can be shown as turbidity white, oil black and oil dark. Generally, when transformer oil is brown or brown, attention should be paid to it or not to use it again. Transformer oil is turbid and white, indicating that it contains water. The darkening of oil color indicates the aging of transformer oil insulation. Oil black, even Coca-Cola flavor, transformer internal faults, therefore, by observing the appearance and color of transformer oil, we can have an idea of transformer oil quality, whether there are internal faults and preliminary speculation of transformer internal faults, we should choose to do experimental projects, so early accurate judgement of transformer latent faults.
1. Polycloudy white oil samples: Increasing hydrogen content and decreasing breakdown voltage are two important characteristics of polycloudy white oil samples.
Generally, if the oil sample is turbid white, it may be caused by the moisture in the oil sample. Objectively speaking, if the gas chromatographic analysis finds that the hydrogen content exceeds the standard, the other gas content is normal and has little change, it can be roughly diagnosed as the moisture in the transformer. At the same time, the breakdown voltage should also be analyzed. Moisture analysis can also be added.
The reason for the large amount of hydrogen in oil samples is the chemical reaction between water and iron and the decomposition of water molecules under high electric field. The reason for the decrease of breakdown voltage caused by water in oil is that the water in oil extends along the electric field direction of the transformer bipolar plane, forming a chain structure and destroying the insulation strength of oil. Sometimes even chain breaking accidents occur.
2. Oil samples are brown or brown, and their acid value and water-soluble acid are close to or higher than national standards. But its chromatographic analysis has no certain regularity.
Generally speaking, the chemical monitoring test of dark transformer oil should be strengthened. Or it should not be used again. Transformer oil should be regenerated to prevent accidents.
3. Oil black: It belongs to normal aging phenomenon according to its gas content and ratio.
The acid value and water-soluble acid value in the analysis exceeded the standard seriously. The increase of acid value in oil products can be regarded as an obvious indicator of the aging phenomenon of oil products.
4. Oil black: Increasing hydrogen and acetylene components is an important feature. The transformer is blackened by carbonization. The content of hydrogen and acetylene increased significantly. Black oil is not recommended.