| 摘要 |
For mobile and stationary power transformers it is desirable to be able to construct a power transformer with maximal external size and in operation to achieve the recommended distance in accordance with the standards between the bushing tops and the earth, while a power transformer must be able to be transported in accordance with the load profile of the railways and must be possible to install or replace the bushings 3 without reducing the oil level in the transformer casing 1, according to Figure 1. This requirement has been solved by an electrically insulating device 4, 5, 7 being fitted to the bushing and the inner part 4 of the device being attached to an intermediate flange 8 of the bushing. The intermediate flange is welded onto the wall of the transformer casing or the cover 2 of the transformer casing. By turning the tube-shaped outer part 5 of the device using a turning device 6, the oil can be shut off in the transformer for the installation or replacement of the bushing. For transportation according to Figure 2 the hole for the bushing is covered with the shutter 9. For the transportation of the bushings there is a special device according to Figure 3, where the oil vessel 10 is filled with the transformer oil 14, the drying apparatus indicated by 11, the drain cock by 12 and the sheet iron cover by 13. The device according to Figure 3 is protection for the bushing during transportation. <IMAGE> |
