Vermont Electric Power Company proposes to upgrade the Tafts Corner Substation to resolve an operational deficiency that would occur during VELCO's routine maintenance and emergency situations. Specifically, the substation currently has an existing transformer that feeds eight local distribution circuits that are radially served. In the event of a transformer failure, VELCO would need to install either a mobile transformer or a spare transformer, and restoration times are estimated to take approximately 24 hours. The proposed upgrade option would:
- reduce risks by eliminating rework of 115 kV circuits;
- support more simplified maintenance; and,
- improve system reliability and load restoration times for emergencies and maintenance.
The Project consists of the following primary components:
- Install a new 115 kV SF6 circuit breaker on existing breaker foundations, make connections to existing 115 kV ring bus, and use existing conduits for control cables.
- Install a new T3 115 kV voltage transformer with a single foundation and steel mounting stand with associated conduits and cables.
- Install protection relays and controls in existing relay/control panels for the 115/13.2 kV T3 transformer and 115 kV K23-40 breaker position, including all required wriring and installation of hardware, fiber optics, and materials.