Development trends in circuit interrupters

Abstract

Several novel circuit interrupting devices are showing possibilities of c o m mercial importance, some representing improvements to oil circuit breakers and others indicating a possible trend toward the non-oil type of equipment. Deion, compressed-gas, expansion, vac u u m , and oil breakers are discussed briefly in the light of present laboratory knowledge. A s s o c i a t e Α. I. Ε . E .Manager» Circuit B r e a k e r E n g i n e e r i n g D e p a r t m e n t W e s t i n g h o u s e E l e c t r i c & M a n u f a c t u r i n g C o m p a n y E a s t P i t t s b u r g h , P a .S EVERAL of the many novel ideas for the interruption of high-powered, a-c. short circuits that have been advanced during the last two or three years present attractive features as compared with conventional equipment. Only tests and field service over a period of time can determine the proper place in the electric power industry for each development, since the various ideas presented are too dissimilar to enable the casual observer to form an opinion of relative merits.At the same time there is a feeling among both the manufacturers and users of high-power circuit breakers that the industry is already too much burdened with complication due to voltage ratings, carrying-capacity ratings, structural arrangements, and many other features more or less special with groups of operating people. It may be conceded that the introduction of radically new forms of circuit-interrupting devices will not automatically simplify present day complication, but unless carefully supervised may only complicate the situation still further.Generally this problem of circuit-interrupting appara tus is subdivided in two ways: first, into indoor and outdoor apparatus; and second, into low-voltage and high-voltage apparatus. In America, practically all switching equipment above 25 kv. is outdoor, so that a view of the situation is simplified by thinking of the problem in two parts; the first, indoor apparatus at 25 kv. and below, and the second, all outdoor appara tus. The merits of a proposed device to meet the requirements of these two classifications is important in connection with newer ideas. F r o m " T h e T r e n d i n D e v e l o p m e n t of M o d e r n C i r c u i t I n t e r r u p t e r s , " ( N o . 3 1 -3 ) , p r e s e n t e d a t t h e Α . I. Ε . E . w i n t e r c o n v e n t i o n , N e w Y o r k , J a n . 2 6 -3 0 , 1 9 3 1 .