National Electrical Installation Standards

Standards as High as Your Own

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Friday, July 13, 2018

Question:

A 12" deep panel is flush mounted in a 8" block wall (Question #1: Allowed?). In the opposing room, there are (2) 6" conduits mounted to strut that has been fastened to the rear 4" of the panel that is sticking out of the wall, which leads to Q2, is mounting the strut to the back of the panel allowed? I found no such information on panels that stick through walls in the NEC, except possibly not a neat and workmanlike installation (110.12).

Thank you. John Kreider

A

Answer:

Hey John thanks for your question. I believe you are referring to panelboards. Panelboards are actually the busses and overcurrent devices and are designed to be placed in a cabinet or cutout box against or in a wall as that term is defined in Article 100. Cabinets can be surface or flush mounted as they are defined in Article 100. Unless there is something in the listing instructions or a concern about the wall having a fire-resistant rating, the NEC does not specifically prohibit the cabinet from extending past the back side of the wall.

Raceways must be secured and supported as stated in 300.11 and by any requirements based on the specific raceway used in the .30 section of the applicable Article. Those rules restrict some things from being used for support but they do not specify what must be used to support the raceways. It is quite possible the installation is installed in a neat and workmanlike manner so even 110.12 might not apply. So a lot of words for it might not be a violation.

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