How long does an oil-immersed transformer change oil? According to the specification, it is often necessary to maintain inspections. However, the actual situation is once a month, and the long-term limit is once every two months. During the operation of the oil-immersed transformer, the deterioration rate of the transformer oil may be affected in different degrees due to the operating environment, operating characteristics, and the nature of the load. Therefore, there is no hard time for changing the transformer oil. According to the actual operation conditions, the transformer oil extraction sample can be subjected to pressure tests periodically and irregularly, and whether or not the results are necessary for replacement can be analyzed.
　　How to change the oil-immersed transformer?
　　First, hang out the oil-immersed transformer body, put clean oil and wash the oil tank. If the body has oil stains, it should also be cleaned. Dry the whole body, then inject new oil and replace all oil-resistant rubber seals. Finally, don't forget to try it out and try it out before you can put it into use.
　　How to dry the oil-immersed transformer?
　　There are many drying methods for oil-immersed transformers. Commonly there are zero phase sequence drying method, vortex drying method, short-circuit drying method, oven drying method, etc. Of course, for larger capacity, higher voltage transformers, the user is best. Do not dry it by yourself. You can send it to a professional manufacturer for vacuum drying. This will not only ensure that the transformer is completely dry, but also will not cause aging of the insulation.