Validity of Unit Testing on Circuit-Breakers Exhibiting Statistically Varying Breaking Capacity

This paper gives some information about the problem of unit testing on high-voltage circuit-breakers. A theoretical investigation of the problem shows that statistical treatment is necessary and that the kind of the breaking process (dielectric or thermal reignition) is also very important. A large number of power tests with one and two units of an airblast breaker are presented. The experimental results agree well with the theoretical investigations. Therefore, direct or synthetic unit testing is not only an economical, but also a valid method for short circuit testing high-voltage circuit-breakers.