Replies

1. 
   mark122 | Aug 14, 2015 06:36am | #1

   not an electrician

   but i want to say, at least here in chattanooga, its 2. 

   if your concerned about code requirements on the amount of cable running through the pvc, why not be concermed about the pvc? 

2. 
   DanH | Aug 14, 2015 08:28am | #2

   I'm pretty sure this is explicily mentioned in the code.

3. 
   barshfield | Aug 14, 2015 12:11pm | #3

   Romex in Short Runs of PVC Conduit

   I spoke with the city electrical inspector this morning and he told me that, for conduit less than 24 inches in length, I am permitted to fill the conduit up to 80% (which then leads one to the code for calculations).  In short, he said up to two 12-2 Romex per 3/4 inch PVC should be fine.  And he is the person who will be doing my inspection. 

4. 
   renosteinke | Aug 16, 2015 09:13am | #4

   Not Allowed

   While not specifically stated, the NEC does not allow Romex to be run within any conduit for any distance.

   The first issue is that the cable needs to be attached to the box with a proper strain relief connector- simply passing it through a pipe prevents you from using such a fitting.

   Wire fill is calculated by assuming that the cable is round, using the largest dimension of the cable. Thus, even one Romex cable would require a 1" pipe.

   There is also the matter of the end of the pipe rubbing on the cable.

   Simply stripping the outer jacket off and passing the wires is also not allowed. Wires in pipes must be marked by the manufacturer as to insulation type, etc .... and the wires inside Romex are not marked.

   Finally, the NEC generally does not allow Romex in crawl spaces at all.

   Going "by the book," you're expected to set a box at the end of the pipe. Within that box you transition from Romex to proper THHN conductors.

   It's common to see homes where the contractor passes all the Romex through a big pipe in the top of the panel. This is also a common violation.

   -------------------------------------

   Those are the 'rules.' That said, in new construction I typically run pipes to the attic and crawl space, to ease future work. Whether the next guy adds a box is his problem; I've just made it unnecessary for him to open up the wall around the panel.

   For particularly 'busy' panels, I will often place a large box (or gutter) remote from the panel and pipe to it; there are only so many openings in a panel top, and I can fit more circuits in a pipe.

   Keep in mind, though, that these boxes must be accessible- without tearing into the wall or ceiling. You have to be able to reach them in their place in the attic or crawl space. Since panels are often placed on outside walls, there is often no roof space above them; you need to continue your pipe to an accessible location.

   -------------------------------

   I'm not completly happy with this state of affairs, but that's a discussion for another forum.

1. 
   DanH | Aug 16, 2015 09:42am | #5

   I suppose this may have changed, but I'm pretty sure my old copy of the code describes the use of conduit in barns to protect romex and states that this is perfectly acceptable.

2. 
   mark122 | Aug 16, 2015 10:15am | #6

   ????

   renosteinke wrote:

   Finally, the NEC generally does not allow Romex in crawl spaces at all.

   either this is very outdated or every house in this part of the world is in violation.

5. 
   renosteinke | Aug 18, 2015 06:49pm | #7

   Not Outdated At All

   Rather, it's a 'clarification' that's about 8 tears old. I'm not saying I agree with it, but it is the code.

   Ordinary Romex is no allowed to be used in 'damp' locations. It's pretty hard to claim that a crawl space is never 'damp.' Even in desert climes, crawl spaces often have standing water on occasion.

   A common violation? You bet. The change, instigated by home inspectors for their egos - they didn't like getting corrected - has certainly let the HI's find something to kvetch about on most homes.

   To be fair, the NEC section on Romex starts out seeming to say it's allowed in damp spaces ... then, a few paragraphs later, narrows this use to a type of Romex that has never been made. "Ordinary" Romex is for dry location use only.

   -------------------------

   As for using short lengths of pipe to protect cables, this is actually a code requirement. Please note that these "sleeves" are placed in specific locations, and do NOT connect to any electrical boxes. For example, sleeves are called for where Romex penetrates floors.

   Is the NEC clear on this topic? As clear as mud.