Maintenance, Repair & Operations

NEC Requirements for Wind Electric Systems

April 21, 2020

Don't miss these key points of Art. 694

Article 694 of the National Electrical Code (NEC) provides the requirements for the electrical portion of wind turbine systems. Turbines continue to get larger, with longer blades and bigger nacelles. This means they are also taller, which makes access more physically challenging for the electrician. You’d better know your NEC requirements stone cold and have the required tools and materials when you climb up there. Climbing down and back up again is time-consuming and exhausting. Fortunately, not all the work is overhead.

Some key points include:

If you install a maintenance receptacle powered by the turbine system, protect it with an OCPD that has a rating not exceeding that of the receptacle [694.7(E)].
You can use the tower as a raceway, but only if it’s listed for that, evaluated as part of the listing, or evaluated for that and a field label is applied 694.7(F)].
Apply overcurrent protection per Article 240 to the turbine output circuits, inverter output circuits, and storage battery circuit [694.15(A)].
Using equipment bonding jumpers, create a unified bonding system between all exposed metal parts that are likely to become energized [694.40].

About the Author

Mark Lamendola

Mark is an expert in maintenance management, having racked up an impressive track record during his time working in the field. He also has extensive knowledge of, and practical expertise with, the National Electrical Code (NEC). Through his consulting business, he provides articles and training materials on electrical topics, specializing in making difficult subjects easy to understand and focusing on the practical aspects of electrical work.

Prior to starting his own business, Mark served as the Technical Editor on EC&M for six years, worked three years in nuclear maintenance, six years as a contract project engineer/project manager, three years as a systems engineer, and three years in plant maintenance management.

Mark earned an AAS degree from Rock Valley College, a BSEET from Columbia Pacific University, and an MBA from Lake Erie College. He’s also completed several related certifications over the years and even was formerly licensed as a Master Electrician. He is a Senior Member of the IEEE and past Chairman of the Kansas City Chapters of both the IEEE and the IEEE Computer Society. Mark also served as the program director for, a board member of, and webmaster of, the Midwest Chapter of the 7x24 Exchange. He has also held memberships with the following organizations: NETA, NFPA, International Association of Webmasters, and Institute of Certified Professional Managers.