| 摘要 |
PURPOSE:To prevent the lowering of the surface of oil, and to enable normal conduction and the change of a tap by forming a small hole for obviating the lowering of the surface of oil to the upper section of an oil purifying pipe mounted into an oil tank for a changeover switch in an on-load tap changer. CONSTITUTION:When oil leaks from external pipings or an oil purifier 9, the surface of oil begins to lower from a conservator 13, and the surface of oil in an oil tank 1 gradually lowers when oil in the conservator 13 is used up. When the oil purifier 9 is operated at that time, the surface of oil rapidly lowers. When the surface of oil lowers up to the height of a small hole 7, however, air intrudes to the external pipings through the upper section of an oil purifying pipe 6 from the small hole 7, thus resulting in the further lowering of the surface of oil up to a section lower than the height of the small hole 7. Since the position, the height, of the small hole 7 is set in an extent that a member taking insulation in oil is not exposed from the surface of oil in order to prevent the lowering of oil, insulation is kept in the oil tank 1, thus enabling the changeover of a tap and conduction. |
