South Carolina is not part of a centralized RTO or ISO. The state operates within several utility balancing areas inside the SERC reliability region: Duke Energy Carolinas in the northwest, Dominion Energy South Carolina in the midlands, Santee Cooper as the state-owned utility, and Central Electric Power Cooperative aggregating the rural cooperatives. The available fault current at a facility service is set by the serving utility, and it shifts when transformers or feeders are upgraded, which is why short-circuit and arc flash studies should be revisited after utility-side work.
South Carolina operates its own OSHA-approved state plan, SC OSHA, run by the SC Department of Labor, Licensing, and Regulation, which covers both private-sector and public-sector employers. SC OSHA adopts the federal electrical safety standards in 29 CFR 1910 Subpart S, which treat NFPA 70E as the consensus standard for arc flash risk assessment and equipment labeling. A current, PE-sealed arc flash study is the documentation a state inspector or an insurance auditor expects to see.
The authority having jurisdiction for the installation itself is typically the local or county building inspection office enforcing the South Carolina Building Code, which incorporates the National Electrical Code. Every study True Power Systems delivers in the state is modeled to current IEEE and NFPA methodology and sealed by a Professional Engineer licensed in South Carolina.