HT Transformer

Error: Air in HT transformer.

We ones had an air bubble in the HT transformer. As we were afraid of a sparking transformer we decided to top up with oil. After the top-up screw was released the relatively small air bubble grew to a very large one. It appeared that the HT transformers are assembled under a low pressure. This is done to allow the walls of the tank to expand when the contents (transformer and oil) gets warm.

Never open the HT tank!!!!