Wireways and enclosures modified for slabbed conduits
What is your opinion about taking a wire way or pull box and cutting a portion out of the bottom of it to Mount over top of PVC conduits coming through a concrete slab beneath a panel? Here is the scenario, in our indoor air conditioned electrical rooms, we like to mount a pull box between the bottom of the electrical panels and the concrete below they're typically about 24 in to 30 inches tall and approximately 20 in wide with the depth of typically 8 in. We generally cut the bottom of the pull box out for the exception of about one inch around the edge and mount it directly over the conduits coming through the slab and secure it to the wall. We also seal between the floor and the bottom. We also add dividers in the boxes as needed to avoid more than 30 ccc in a cross section. Do you see any issue with this? It makes for a very clean looking end product.
I think that is entirely up to your AHJ and what I might say about it is irrelevant. That would more than likely be better served in either the 2020, 2023, or 2026 Space rather than in the general discussion forum. Remember, you have to JOIN the spaces for them to show up in posting to the general feed or you can go directly that specific space and JOIN and it will show up in the future.
This actually sounds more like an Auxiliary Gutter to me as it appears to be affording you additional wire space in route to the panel and those are required to be listed. However, if we stick with your box being a wireway, and not listed lets say, then if you make it and it meets the dimentions necessary where being used as a pull box, and even if you don't pull through it, its still a pull box as well.
Now, if you buy them and they happen to actually have a listing on them by chance and you use it outside of the listings they evaluated if for then you have a 110.3(B) issue even if listing was not required. Just so you know listing is required in wet locations so just want to make that clear.
Ultimatly the NEC doesn't require metal wireways to be "listed" but if it was and you alter it then you are voiding that listing and once it is listed, its listed.
So the manufacturer that we order them from cuts the bottom out for us after we have them the dimensions, so they are fabricated and painted gray before they ever get to us and they aren't listed when they arrive to us. It is a really great company that we order them from and we've done business with them for probably 20 years, they do stainless Custom Cabinets as well and standard cabinets also. I appreciate the insight. I've never had an issue with an inspection but it's always made me wonder. I really just like the way the installation looks because it's clean
David Shockley Those sounds like simply an open bottom box and we see lots of those. In that case then I would not see any issue with them again as long as they meet the dimensions for pull boxes in the NEC.