In the process of transportation, storage and management of insulating oil, the moisture will be dissolved in oil, it may enter moisture. Generally, the insulating oil dissolving water capacity is about 500-1000ppm at 20° C. The water content can be reduced to 3-5 ppm through a Vacuum Transformer Oil Dehydration Plant. In addition, the moisture absorption of the oil is related to the humidity of the air. The oil temperature increases linearly, for example, if the oil sample is 60~(3, relative humidity is 40%, the water content in the oil is 80*10~, when the relative humidity is 80%, the water content in the oil reaches 200*10. The oils of different chemical compositions can have a water absorption of several tens of 10 "differences. The more aromatic hydrocarbons in the oil, the higher the moisture absorption of the oil, and the presence of certain polar molecules in the oil. Also can increase the moisture absorption of oil.

Bad effects of moisture on of insulating oils:

Moisture has great harm to the electrical properties and physical and chemical properties of the insulating medium. First, the moisture will reduce the breakdown voltage of the oil. According to reports, when the oil contains 0. At Ol%, the breakdown voltage is about 15kV when the water content increases to O. At 03%, the breakdown voltage drops to about 6kV, and moisture also has a significant effect on dielectric dissipation factor. With the increase of moisture within the oil, the dielectric loss factor increases. When the water content in the oil is 0.02%, the dielectric dissipation factor is 1×10_. When the water content increases 15 times, that is, O. At 10%, the dielectric loss factor increases to 2.1 x 10~. In addition, moisture can also promote the organic acid corrosion of copper, iron and other metals, the resulting saponification will deteriorate the dielectric loss factor of the oil, increase the moisture absorption of the oil, and catalytic oxidation of the oil. It is generally believed that oil that has been exposed to moisture will increase its aging rate by 2-4 times than that of dry oil. Therefore, people have paid great attention to the existence of water in insulating oil for a long time. At present, both the domestic and foreign transformer oil standards are required to control the moisture content at about 40×10′′.

If there is only a small amount of moisture and impurities in the insulating oil, the breakdown voltage of the oil will decrease, and the water or impurities in the oil will increase the dielectric loss factor. When it is found that the insulation oil is deteriorating and the electrical performance is degraded, the oil must be purified. When the insulating oil enters moisture, we can use Vacuum Transformer Oil Dehydration Plant to remove water, gas and impurities to recover the performance of insulating oils.