The existing 60-kV switches are hard to use, require extensive maintenance, and often draw large arcs during operation. Most of these switches were installed over 14 years ago and are not designed for loads that the system currently has. The replacement of these switches with 60-kV circuit breakers was scheduled as part of the 60-kV Network. The completion of this network has been postponed due to other higher priority projects. However, this project cannot wait, as it is a safety item.
This project entails installing three 60-kV breakers at Southeast Substation, one at Vernon Substation, two at Cirby Substation, and three at Hardrock Substation. The project also involves the installation of the associated foundations, visual and lockable disconnects, wiring, and a remote “Open/close” switch. Steel poles and structures will be needed for each substation as well as deadend poles and stands.
The existing 60-kV switches are difficult to use, and cannot be used under high-load conditions. Changing out the switches to circuit breakers will create a safer work environment and allow switching to occur at any time.
Breaker upgrade at Southeast, Vernon and Cirby were completed. Hardrock substation upgrade will complete by summer 2010.