Specific Requirements For Oil-immersed Transformers

1. After long-distance transportation, the transformer will be subjected to greater vibration and needs to be inspected. The transformer body inspection is divided into hanging core and hanging cover. Regardless of the hanging core or hanging cover, the inspection content is the same. The hanging core inspection should be completed within one working day to speed up the inspection process.
2. Take the hanging core inspection as an example: ⑴ The transformer core should be hung indoors. If it is outdoors, there should be a tent to prevent the hanging core from being prohibited in bad weather such as rain, snow, fog, wind and sand. ⑵ The hanging core temperature in winter shall not be lower than zero degrees, otherwise the transformer will be heated to make the core temperature higher than the ambient temperature by 10℃. ⑶ The shorter the time the core is exposed to the air, the better. It should not exceed 16 hours when the relative humidity is 65%, and should not exceed 12 hours when the relative humidity is 25%. The calculation time is from the start of oil discharge to the end of oil filling. ⑷ When the relative humidity exceeds 75%, the hanging core inspection is not allowed. ⑸ During the hanging core inspection, special attention should be paid to prevent parts and tools from falling into the oil tank.