Switching and transient phenomena in a series design of two vacuum circuit breakers

This contribution deals with the investigation on the switching process of a series arrangement consisting of two 24-kV-vacuum circuit breakers and the assessment of the relevant transient phenomena occurring between the two chambers and their grading capacitors. In the first part of the paper the switching capability of the double arrangement is compared to a single tube of the same design. The physical behaviour of the series design in case of reignition of one of the tubes is presented in the second part of the paper. The observation of the transient oscillating currents between the vacuum tubes and their grading capacitors in the range of some μs shows the decisive influence of this parameter on the reignition processes and the resulting breaking capability.