New testing method for the classification of contact materials for vacuum circuit breakers

A new testing method to classify contact materials for high-current interru ption with vacuum circuit breakers (VCB) is described. The testing effort i s reduced by diminishing the contact gap and the contact area as well as by an adequate testing circuit. Consequently, the number of experiments can b e increased for the benefit of a high statistical certainty in the classifi cation of contact materials. The test results are in good agreement with th e results of full-size short-circuit current interruption tests carried out in a high-power testing laboratory with VCB equipped with contact material s classified in the new testing circuit.