Application of Wound Type Current Transformers Installed in High-Voltage Oil Circuit Breaker Tanks

Wound type current transformers installed in the tanks of high-voltage oil circuit breakers have been in operation for many years. The experience gained during this period has resulted in fairly clear definitions as to the types of installations to which they are best suited, and to designs of transformers which are highly reliable. The purpose of this paper is to present a brief history of some of the developments leading up to the present application of wound type current transformers in circuit breakers and to indicate some of the conditions under which they offer special advantages.