- Fulton Springs 115-kV Switchyard
To improve reliability and operability of their 115-kV system, Alabama Power required an upgrade of their Fulton Springs Substation, located north of Birmingham, Alabama. Prior to the upgrade the Fulton Springs arrangement consisted of manually-operated disconnect switches mounted on a lattice structure. The 115-kV portion of the station allowed pass-through of transmission lines that could be connected in a limited number of arrangements.
Due to limited flexibility of the existing system and ongoing transmission upgrade projects, the substation was required to maintain service throughout the construction period. Therefore, the new arrangement was constructed under energized transmission lines with no outages.
Burns & McDonnell and their joint venture partner New River Electrical provided turnkey services to complete the project on time with an aggressive schedule. Burns & McDonnell procured all engineered equipment and New River provided commodity materials.
The new 115-kV equipment is in a breaker-and-a-half configuration with a 3000A main bus and four 2000A bays. The power circuit breakers have an interrupting rating of 63-kA and the bus and grounding systems are designed for 50-kA available fault current.
Spread footings were used and locations of piers for dead-end structures were located to allow excavation under energized lines. During the geotechnical investigation portion of design phase, solid sandstone was encountered within seven feet of the surface requiring five six-foot diameter 11-ft deep rock sockets. Burns & McDonnell and New River subcontracted the rock drilling to an industry specialist.