Rigid Nonmetallic Conduits
- Thread starter atr
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bphgravity
Senior Member
- Location
- Florida
Re: Rigid Nonmetallic Conduits
I don't believe so. Section 230.50(A) of the NEC 2002 permits service cables to be protected by schedule 80 RNC, and there is nothing in Article 352 that prevents its use in this manner.
I don't believe so. Section 230.50(A) of the NEC 2002 permits service cables to be protected by schedule 80 RNC, and there is nothing in Article 352 that prevents its use in this manner.
sandsnow
Senior Member
- Location
- Southern California
Re: Rigid Nonmetallic Conduits
Watch out going through plenum. Most mid to high rise bldgs use a non-ducted return, therefore plastic not allowed above T-Bar. In most cases you would be in the electrical rooms so it would not be an issue there.
Firestopping may be easier to address because non metallic conduit acheives a T rating easier. A mid to high rise building would probably be TYpe I or II per the UBC and require at least 1 hour seperation between floors.
Watch out going through plenum. Most mid to high rise bldgs use a non-ducted return, therefore plastic not allowed above T-Bar. In most cases you would be in the electrical rooms so it would not be an issue there.
Firestopping may be easier to address because non metallic conduit acheives a T rating easier. A mid to high rise building would probably be TYpe I or II per the UBC and require at least 1 hour seperation between floors.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Rigid Nonmetallic Conduits
Actually 230.43 allows the use of schedule 40 RNC where not subject to physical damage. But this would depend upon your AHJ's interpretation of what's subject to physical damage.
Actually 230.43 allows the use of schedule 40 RNC where not subject to physical damage. But this would depend upon your AHJ's interpretation of what's subject to physical damage.
Re: Rigid Nonmetallic Conduits
I usually do residential but recently a lot of commercial has came my way. I'm so tempted to use the plastic stuff but every time I look at the work around the city, I never see plastic (1/2" to 2" plastic) hung on the walls. I see 3"plastic used. I have rarely used plastic but the price is so tempting.
I usually do residential but recently a lot of commercial has came my way. I'm so tempted to use the plastic stuff but every time I look at the work around the city, I never see plastic (1/2" to 2" plastic) hung on the walls. I see 3"plastic used. I have rarely used plastic but the price is so tempting.
shocker3218
Senior Member
Re: Rigid Nonmetallic Conduits
nonmetalic is definately cheaper in walls where strapping is easier, however I would hesitate to use it anywhere else due to the fact it has to be supported at 3 ft intervals. May run up a lot of expense with a large rack. And then converting from nonmetalic to emt could be troublesome. For my money, I still bid all jobs with emt. Smurf might be another option, but I don't like the looks of that either. (MC and flex are not allowed in my jurisdiction)
nonmetalic is definately cheaper in walls where strapping is easier, however I would hesitate to use it anywhere else due to the fact it has to be supported at 3 ft intervals. May run up a lot of expense with a large rack. And then converting from nonmetalic to emt could be troublesome. For my money, I still bid all jobs with emt. Smurf might be another option, but I don't like the looks of that either. (MC and flex are not allowed in my jurisdiction)
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: Rigid Nonmetallic Conduits
PVC has a high coefficent of thermal expansion. IMO it only is good underground and in corrosive areas.
What about fiberglass? I would like to try fiberglass for pole risers, if anyone has a product they have used and is readily available let us know.
PVC has a high coefficent of thermal expansion. IMO it only is good underground and in corrosive areas.
What about fiberglass? I would like to try fiberglass for pole risers, if anyone has a product they have used and is readily available let us know.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Rigid Nonmetallic Conduits
I always thought that PVC is somewhat restricted on indoor installations because of the smoke producing characteristic's of it. I know it can be used indoors but what would be the limits?
I always thought that PVC is somewhat restricted on indoor installations because of the smoke producing characteristic's of it. I know it can be used indoors but what would be the limits?
sandsnow
Senior Member
- Location
- Southern California
Re: Rigid Nonmetallic Conduits
The smoke producing urban legend is just that. I was told many years ago that the smoke produced was toxic therefore it could not be used inside. Well there is no code provision to back that up. It was just people who were resistant to change and looking for any reason to restrict use of plastic conduit.
Here in the modern age Sch 40 and Sch 80 when listed for aboveground use (and I believe it all is) has limits in theaters, health care facilities, and wiring for fire pumps. Aside from the plenum restrictions it would be fine for general use wiring. If the demand is great enough don't be suprised if a manufacturer finds a way to get it UL listed for plenum use.
The smoke producing urban legend is just that. I was told many years ago that the smoke produced was toxic therefore it could not be used inside. Well there is no code provision to back that up. It was just people who were resistant to change and looking for any reason to restrict use of plastic conduit.
Here in the modern age Sch 40 and Sch 80 when listed for aboveground use (and I believe it all is) has limits in theaters, health care facilities, and wiring for fire pumps. Aside from the plenum restrictions it would be fine for general use wiring. If the demand is great enough don't be suprised if a manufacturer finds a way to get it UL listed for plenum use.
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