American Transmission Co. projects

Project website for a Wisconsin-based company that owns and operates the high-voltage electric transmission system that powers communities in portions of the Upper Midwest.

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ATC restarting electric system in Michigan’s Upper Peninsula

PEWAUKEE, WI — American Transmission Co., owner and operator of the electric transmission system in Michigan’s Upper Peninsula, is working to bring the transmission grid in the UP back on line following an apparent lightning strike to two key 138,000-volt transmission lines at approximately 3:30 this morning between Oconto County, Wis. and Dickinson County, Mich. As a result, the western two-thirds of the UP experienced an electrical system outage as a 345,000-volt transmission line that also serves the UP was out of service for a planned outage. Subsequently, the instability of the system triggered the automatic shutdown of Presque Isle Power Plant in Marquette, Mich., to protect the system.

ATC and local utilities have been coordinating the methodical restart of the electric system today including restoring the transmission system and bringing generating units at Presque Isle Power Plant back on line. ATC expects the transmission system to be fully operational by early this afternoon, which will enable local utilities to return electric service to customers. Some customers already have had service restored.

ATC continues to conduct helicopter and foot patrols to inspect transmission lines.

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ATC is a Wisconsin-based company that moves energy along the regional electric grid in parts of Wisconsin, Michigan, Minnesota and Illinois, serving more than 5 million electric consumers. We are experts at what we do: planning, maintaining, operating and protecting the grid. As the electric industry moves toward renewable generation sources, we are transforming our system to continue delivering energy reliably and safely. We proudly support STEM education programs that empower youth with the skills needed to succeed in tomorrow’s energy workforce. For more information, visit www.atcllc.com and follow us on LinkedIn and X (Twitter).