Vacuum technology

Although the use of vacuum technology started off in medium-voltage power transformers and high performance contactors, its importance is now also growing with regard to applications for on-load tap-changers. We are the first manufacturer to introduce vacuum technology for on-load tap-changers.  In this respect we have been relying on empirical values since the beginning of the eighties. These are based on vacuum switches for the North American market for which special interrupters were developed. Further development and optimising meant that vacuum technology attained the high degree of technical maturity required for on-line tap-changers. Thanks to high-tech manufacturing processes our vacuum interrupters have become so compact that they can fit into conventional tap-changer constructions with room to spare.
As the vacuum interrupters are an hermetically closed system, occurrences of arcs no longer contaminate the ambient environmental medium.  This means:

  • in contrast to the switching medium insulation oil, there is no longer any carbonation ;
  • there is no longer any need for the oil filter unit for cleaning the environmental medium, that was formerly needed in certain applications;
  • replacement of the switching/resistor contacts is no longer needed;
  • clean oil makes maintenance work easier;
  • the longer service life of the oil helps conserve this valuable resource;
  • there are no problems disposing of the oil because it is not contaminated;
  • consistent switching capacity of the vacuum interrupters over the whole service life;
  • maintenance free up to 300,000 switching operations;
  • longer maintenance intervals, less maintenance required, lower maintenance costs;  
  • simplified servicing logistics;
  • increased availability of the transformer.

This environmentally sound innovation with its optimised use of resources, an innovation that fulfils so many customer requirements, means that we have not only ensured our position of world market leader but have also taken the lead in technology as well.

News of our vacuum technology