Two-Bank 69 kV Substation for a
Dedicated Generating Plant
Sundt brought Southern Switch in as the electrical erection subcontractor on a new two-bank substation at MacDill in Tampa, built to serve a small generating plant dedicated to the base. Across two phases in 2024, Southern Switch set the structures and installed and wired the 69 kV high-side switching for both banks. The two power transformer banks were built out separately by TECO.
A switchyard for
on-site generation.
The project stood up a small generating plant dedicated to MacDill, on the base footprint. Sundt held the prime contract for the build. The high-voltage scope, the structures, the 69 kV switching, the breakers, and the instrument transformers, went to Southern Switch. The two power transformer banks were TECO’s own scope.
Southern Switch and Sundt walked the site together and generated a detailed work scope from that walk. The build then ran in two phases off that scope.
What Southern Switch
built and wired.
Across the two phases, Southern Switch erected the structures and installed the complete 69 kV high side for both banks, then terminated it and left it ready for energization.
- →Mobilized and erected 12 steel structures across the two phases
- →Installed two 69 kV switch sets with motor operators
- →Installed two 72.5 kV circuit breakers
- →Set three potential transformers (Phase 1)
- →Installed shielding cable, post insulators, bus, and conduit
- →Supplied DMC connectors, 1590 kcmil conductor, 3/8-inch EHS shield wire, bus, connection hardware, conduit, and Unistrut
- →Two power transformer banks (built out by TECO)
- →Circuit breakers, switches and operators, and PTs (installed by Southern Switch)
- →Post insulators, junction boxes, arrestors, and grounding material
Scope by phase.
Why the switchyard
is the whole job.
A dedicated generating plant is only as good as the substation that ties it in. The 69 kV switching, the 72.5 kV breaker ahead of each bank, and the instrument transformers are what let the plant isolate, protect, and meter its output. Getting the structures plumb, the bus tensioned, and the shield wire dead-ended right is the difference between a bank that energizes clean and one that gets found on the first fault.
Both banks,
ready for energization.
A two-bank 69 kV substation built and wired across two phases in 2024. Twelve structures set. Two 72.5 kV breakers and two motor-operated 69 kV switch sets installed and terminated. Three potential transformers set. All of it performed on an active MacDill site as a subcontractor to Sundt, with TECO building out the two transformer banks.
Southern Switch builds and wires substation banks as an electrical erection contractor: structures, switches, breakers, instrument transformers, bus, and conduit, from site walk to energization-ready. Send us your scope.