National Electrical Installation Standards

Standards as High as Your Own

Wednesday, November 29, 2017


Can an old panel be used as a junction box and then a new panel be installed over the front of old one. Basically no access to the J box?

Steve Methven



Hey Steve thanks for your question. In general splices must be made as described in 300.15 and are usually described as required to be accessible as that word is defined in Article 100. Panelboards are typically enclosed in cabinets which are allowed to be used as stated in 300.15(I). Covers are required to be accessible after installation as stated in the last sentence of 300.15(A). If installing the new panelboard over an existing cabinet did not allow access to the splices then most AHJ's would likely not allow it - even though the wording is not as clear as it could be.

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