摘要 |
The invention relates to a vacuum circuit breaker for alternating current. The breaker has two contact electrodes (6, 7), which are arranged to be separated from each other at the opening of the breaker. According to the invention, synchronising means (9) are arranged to start the separation movement of the contact electrodes (6, 7) within a certain time window (T). The time window ranges from the moment of one zero-crossing of the current until 1 ms before the next zero-crossing. By this synchronisation, re-strikes are avoided which otherwise might occur if the opening is started shortly before a zero-crossing. The invention also relates to a corresponding method of interrupting an alternating current, to the use of the invented breaker and to an electric power network including the invented breaker. |