A new 50,000-kva 5-kv oilless circuit-breaker and metal-clad switchgear unit

THE obvious advantages of air circuit breakers have led to their widespread application, particularly in the 2,500 and 5,000-volt class for 100,000 and 150,000-kva interrupting rating. This has in turn brought a demand for lower kilovolt-ampere ratings in these voltage classes. In the past the oil circuit breaker has been the only device economically applicable in this particular field. However, progress in design and manufacturing facilities has made it possible to build a 50,000-kva unit lower in cost than would have been considered feasible two years ago and one which is expected to meet the operating requirements in this field.