On the finished active part, the assembled cover is screwed with bushings and everything is interconnected.
![](https://www.czechtrafo.cz/wp-content/uploads/2022/03/plneni01-1024x576.jpg)
Fig. 1. The wires must first be cleaned of paint and roughened before connection
![](https://www.czechtrafo.cz/wp-content/uploads/2022/03/plneni02-1024x576.jpg)
Fig. 2. The bushings, tap changer and coils are then connected
This prepared active part is then placed in a tank and is ready to be filled with oil under vacuum and subsequently hermetically sealed.
![](https://www.czechtrafo.cz/wp-content/uploads/2022/03/plneni03-1024x576.jpg)
Fig. 3. Before filling with clean and degassed oil, the entire inside of the transformer must be removed of residual moisture. The whole process is carried out under vacuum.
![](https://www.czechtrafo.cz/wp-content/uploads/2022/03/plneni04-1024x576.jpg)
Fig. 4. Transformers are placed under the bell under which the vacuum is created and connected by pipelines to the oil management. We will lower the bell and begin filling.
![](https://www.czechtrafo.cz/wp-content/uploads/2022/03/plneni05-1024x576.jpg)
Fig. 5. A quick peak inside with the bell closed
![](https://www.czechtrafo.cz/wp-content/uploads/2022/03/plneni06-1024x576.jpg)
Fig. 6. Test of the parameters and the product can be delivered to the customer.
![](https://www.czechtrafo.cz/wp-content/uploads/2022/03/plneni07-1024x576.jpg)
Fig. 7. Without the birth certificate (Test report) it wouldn’t work any other way
![](https://www.czechtrafo.cz/wp-content/uploads/2022/03/plneni08-1024x576.jpg)
Fig. 8. Finished products ready for dispatch to customers
![](https://www.czechtrafo.cz/wp-content/uploads/2022/03/plneni09-1024x576.jpg)
Fig. 9. One more detail to say goodbye