Line-Dropping Tests on a 330-Kv Oil Circuit Breaker [includes discussion]

The development of the 330-kv transmission system of the American Gas and Electric Company (AG&E) and of the Ohio Valley Electric Corporation (OVEC) involved the installation of a great number of circuit breakers. The AG&E 330-kv system is superimposed on existing 138-kv transmission facilities. The OVEC 330-kv system was built to supply power from two new generating plants to the Atomic Energy Commission´s diffusion plant at Portsmouth, Ohio. The OVEC system is owned by 15 private utilities and is interconnected with the AG&E 330-kv system. Particularly in the case of OVEC, it is of the greatest importance to prevent, or limit in duration, unscheduled interruptions which could result in costly damage at the processing plant. To attain and maintain this high degree of service reliability, AG&E has made it a standard practice to field test new equipment whenever possible and, if required to apply the results to the betterment of the equipment and the service. The line-dropping investigation described in this paper is one of several carried out or planned in pursuance of these objectives. The particular circuit breaker described herein was completely restrikefree in its performance.