Vacuum retrofit modernization of air and oil circuit breakers: the process, benefits and risks of applicable standards

Electric utilities have undergone extensive life extension evaluations of many power plant components. The goal has been to obtain an impressive extension of equipment or system life, at the least cost expenditure. This process effectively improves the reliability of plant systems, whereas improvements in maintainability usually are of secondary importance. In many cases, the plant´s electrical distribution system, and in particular, the air and oil circuit breakers have not been part of the life extension evaluations. This paper addresses upgrading the older air and oil circuit breakers, utilizing newly manufactured vacuum circuit breakers. The result is improvements in system reliability, maintainability and life extension of the electrical distribution system with the least expenditure of monies