Fault Analysis of Oil-immersed Transformer

Oil-immersed transformer weld seam oil leakage

The main reason is that the welding quality of the oil-immersed transformer is poor. The welds of oil-immersed transformers have defects such as false welding, desoldering, pinholes and air bubbles. It was covered by flux and paint when leaving the factory, and hidden dangers were exposed after operation.

Additionally, electromagnetic vibrations can cause welds to crack and cause leaks. For oil-immersed transformers that have leaked, first of all, find out the leak point, you should not miss it. For severe leaks in the transformer, metal tools such as a flat shovel or a sharp punch can be used to rivet the leak. After containment of oil-filled transformer leaks, the treated surface is cleaned, usually cured and cured with a polymer composite. After that, the purpose of long-term leakage control can be achieved.

                                                     YD series oil-immersed test transformer

Poor sealing of oil-immersed transformer

The oil-immersed transformer is poorly sealed. Usually, the seal between the tank edge and the tank cap is sealed with an oil-resistant rubber rod or a rubber gasket. If the oil-immersed transformer joints are not handled properly, it will cause oil leakage failures. Some transformers are strapped with plastic straps, and some simply have the ends pressed together. Due to the rolling during the installation process, the interface of the oil-immersed transformer is not pressed firmly and cannot be sealed, and oil is still leaking.

This material can be used for bonding, so that the oil-immersed transformer joints form a whole, and can greatly control the oil leakage. If the operation is convenient, the metal shell of the oil-immersed transformer can also be bonded at the same time to achieve the purpose of leak prevention.

Oil leakage at flange joints of oil-immersed transformers

The flange surface of the oil-immersed transformer is uneven, the fastening bolts are loose, and the installation process of the transformer is not correct, resulting in improper bolt fastening and oil leakage. After tightening the loose oil-immersed transformer bolts, seal the transformer flange, and deal with the bolts that may leak, so as to achieve the purpose of thorough treatment. To tighten the loose oil-immersed transformer bolts, the operating procedures of the oil-immersed transformer must be strictly followed.