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PVC Conduit

Posted by ecranny (My Page) on
Wed, Apr 7, 10 at 22:28

I am installing a sub-panel in my basement, and I am hoping to use an existing (unused) conduit to run the feed from the main panel, using copper wire (3 * 2awg + 6awg ground). The conduit is Schedule 40 PVC, 1.5 inches, and I believe I am ok as far as fill factor and ampacity goes. The only problem might be that the conduit runs directly behind drywall with no gap, and parallel to a stud - there is no 1 1/4 inch clearance. According to 300.4(D) Exception No 1, rigid nonmetallic conduit is ok in this situation, with no steel plates, sleeves required. My Questions is: does Schedule 40 PVC count as 'rigid nonmetallic conduit' in this case?


Follow-Up Postings:

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RE: PVC Conduit

" there is no 1 1/4 inch clearance"

Not sure were you are getting this requirement from.

Even NM cable does not require 1.25 in clearance if parallel to the studs.

Bored holes in the studs require the clearance (or nail plates) to protect from drywall fasteners holding the drywall to the stud.


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RE: PVC Conduit

Brickeyee, as I mentioned in the post, this requirement is from 300.4(D) Cables and Raceways Parallel to Framing Members and Furring Strips. It requires that cables or raceways are not less than 1 1/4 inch from the nearest outside surface where nails or screws are likely to penetrate. If that clearance can not be maintained, a steel plate or sleeve must be installed. I read that mean that NM or raceways that are attached to the stud must be at least 1 1/4 inch back from the front of the stud. My question is whether Schedule 40 PVC qualifies as Rigid Nonmetallic Conduit as noted in Exception No. 1


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RE: PVC Conduit

If yo0u are using listed rigid non-metallic conduit you are under the exception.

What is the marking on the conduit?


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RE: PVC Conduit

it is Schedule 40 - the wall is thinner than Schedule 80, so I need to know if Schedule 40 is ok, or if I need to replace it with Schedule 80


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RE: PVC Conduit

It should have an article number from the NEC or some other legend.

Plumbing pipe is not acceptable.


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RE: PVC Conduit

It is electrical PVC conduit (not plumbing or anything else), Schedule 40. I was hoping someone would be able to tell me that it satisifies the code requirements, but since I am having no luck I have decided to replace it with EMT, because I am having a hard time finding a source of Schedule 80 non-metallic tubing....


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RE: PVC Conduit

If it is marked as rigid non-metallic tubing it complies.

Article 352 covering RNC does not even call out schedule size. That is really a plumbing convention were pressure is concerned.

352.100 refers tyo refers to 110.21 and requires RNC to be marked with manufacturer's name, trademark, or other descriptive marking to identify the manufacturer.

Pull a cut sheet from the manufacturer and see what the actual listing says.


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