National Electrical Installation Standards

Standards as High as Your Own

Thursday, May 12, 2022


Hello Code Forum,

If I install an LED sign on a building soffit, is access required to the power supplies and, do I need walkboards installed in the attic space of the soffit?

Thanks for any guidance.

Bill Hart



Hi Bill,

You might want to check Section 600.21. Section 600.21(A) indicates that ballasts, transformers, electronic power supplies, and Class 2 power sources shall be located where accessible and shall be securely fastened in place. Section 600.21€ is more specific and indicates that ballasts, transformers, electronic power supplies, and Class 2 power sources shall be permitted to be located in attics and soffits, provided there is an access door at least 36 in. x 22.5 in. and a passageway of at least 3 ft high x 2 ft wide with a suitable permanent walkway at least 12 in. wide extending from the point of entry to each component. At least one lighting outlet containing a switch or controlled by a wall switch shall be installed in such spaces. At least one point of control shall be at the usual point of entry to these spaces. The lighting outlet shall be provided at or near the equipment requiring servicing. Hope this is useful.

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