National Electrical Code

Grounding and Bonding of Electric Signs and Outline Lighting

Dec. 4, 2018

Do you know when to use an equipment grounding conductor?

Simply connecting the green power ground to the appropriate terminal at the sign, outline lighting, or skeleton lighting isn’t sufficient. In addition, you must ensure all the metal equipment of these systems are bonded to the equipment grounding conductor (EGC). So, if you have a metal junction box, bond it to an EGC.

Use an EGC that is one of the types specified in Sec. 250.118 of the 2017 National Electrical Code (NEC). Size your EGC per Sec. 250.122 after determining the rating of the overcurrent device protecting the circuit conductors supplying the system in question.

Make the EGC connection per Sec. 250.130, using a method specified in Sec. 250.8. For example, don’t rely on a raceway locknut connection to the junction box for your effective path. If in doubt, take an extra few minutes to run a bonding jumper.

If your installation specification calls for a grounding electrode, remember it’s only an auxiliary grounding point. Your EGC must run back to the power supply because you need a low impedance path for electricity to get back to its source.

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.