RNC Threading

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necbuff

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Is it permissible to thread Sch 40 or 80 RNC. The code is not clear. It is specific in 358.28 (B) regarding EMT but not RNC. IMO it is common sense NOT to thread it. I have a contractor who threads 2" sch 40 on his services I can not find anything concrete to prohibit it. I am not one for making my own rules and I have not said anything but this drives me nuts. 352.46 & maybe 358.48 is the best the RNC article has to offer and that is a stretch. I hardly think it is intended to be threaded. It would appear the rating and the integrity of the wall would be compromised. I think a proposal is in order on this issue. I have some pictures of the latest installation, approx 2.5 ft long section of threaded sch 40. I will post them if someone will give me an address.

[ April 19, 2005, 11:20 PM: Message edited by: necbuff ]
 
Re: RNC Threading

necbuff,
I'll bite..What is his intent of useage with a section of threaded RNC...? :confused:

[ April 19, 2005, 11:52 PM: Message edited by: dillon3c ]
 
Re: RNC Threading

This is not a line Bro, He does it so he does not have to buy fittings. It is the weirdest thing. It looks like a piece of 2" plastic all-thread :D . Normally he just uses it as a short nipple. I am guessing he threads a long piece and cuts it the whatever length he needs it.
 
Re: RNC Threading

352.48 ...says "approved", not listed/labeled. The AHJ must approve/disapprove the installation.

225.52 also maintains that raceways shall be raintight (exterior). The question is...does threading violate "raintight" in this application? The manufac. would probably know.


PS. to post a picture, upload the photo to a free image hosting site (such as snapfish.com), then copy the image location and add it to your post using the "IMAGE" button (below where you enter text ~ under "Preview", under Instant UBB Code...see box labeled "Image"?
image.gif

PM me if you need additional help.
 
Re: RNC Threading

How is he getting by 352.6 -associated fittings-?

[ April 19, 2005, 11:56 PM: Message edited by: dillon3c ]
 
Re: RNC Threading

Clarification... He only uses the threaded nipples between the meterbase and panel. Mostly back to back services.
 
Re: RNC Threading

...maybe the guy is (gasp! :eek: ) right!

I was always told "running threads" are not allowed (344.42/RMC)...then again, I don't think I would thread RNC - which just seems nutty.

How much could he possibly be saving use 2" all thread(LOL) and a couple of locknuts vs. 2 adaptors? ...or maybe he's one of those "...looks good from my house/...it'll never be seen" types?

I would have to make a call to the manufac. and get the answer direct if I were the AHJ or other "interested" party.

{EDIT: I can't spell and I'm not pressing that button...LOL]

[ April 20, 2005, 12:13 AM: Message edited by: celtic ]
 
Re: RNC Threading

necbuff,
Brother, 352.6 Listing Requirements-

Article 100-Listed- I see in this statement-"acceptable to the authority having jurisdiction".. Guess that might be you Inspector..

Inspection department in my area would have puppies,before approving that installation..

Edited:352.6-Listing requirements:associated fittings...Would fittings be required, being the question?...I think they would..

...Can you thread RNC...?
->http.//www.carlon.com/ContactUs.html.

[ April 20, 2005, 01:07 AM: Message edited by: dillon3c ]
 
Re: RNC Threading

From the UL White Book

"RIGID NONMETALLIC, SCHEDULE 40 AND SCHEDULE 80 PVC CONDUIT (DZYR)

PVC conduit is designed for connection to couplings, fittings and boxes by the use of a suitable solvent-type cement. Instructions supplied by the solvent-type cement manufacturer describe the method of assembly and precautions to be followed."

Seems to me that you would be violating the listing. :D
 
Re: RNC Threading

Well, you know how us electricians are. We will take it to the limit unless written in crayon :D . But you see my point. EMT specificly prohibits threading where RNC does not. It is just a loophole for someone to argue. BTW, I am the AHJ but you can see the argument. It is one of those things you know just aint right but arguable.

[ April 20, 2005, 07:42 PM: Message edited by: necbuff ]
 
Re: RNC Threading

You can thread schedule 80 PVC water pipe if you derate the pipe pressure rating to schedule 40. Never heard of threading RNC before but seems to be more labor than using a threaded adapter.

Some electrical utilities prohibit using the rear knockouts of a meter socket when mounted on a building. There are 3 reasons for this:

1. It is almost impossible the seal the opening against moisture coming in from the outside.

2. It can cause moisture from inside of the house to condense or even freeze on the backside of the socket.

3. It makes it harder for some meter readers to tell if there is an illegal connection.

I one time did get a variance from First Energy for a 400 amp single phase service where I had built a socket mouting frame out or redwood and foamed the entire backside of the socket. They did get a chance to inspect the interior before interior finish was installed to see that I had foamed the backside of the socket. Also, if I had done things using LBs on the outside the meter socket would have been too high or I would have had to break into a concrete block wall and into a concrete floor slab.

If you need an exception to an electrical utility's rules you can usually get a variance ( within reasonable parameters ) if you can show on a drawing that your idea will work equally well.
 
Re: RNC Threading

I wouldn`t want to clean the dies of sch 80 rnmc from my threaderng machine ;) M/A and some glue cheap and quick :cool:
 
Re: RNC Threading

In my opinion based on the following: Rigid nonmetallic conduit PVC schedule 40 and 80 are not allowed to be field threaded, according the UL white book, under (DZYR), it states; "PVC conduit is designed for connection to couplings, fittings and boxes by the use of a solvent-type cement." So it is legal to use cement to attach a threaded fitting to the conduit. Cite section 110.4(B) for violations.
 
Re: RNC Threading

Originally posted by john m. caloggero:
In my opinion based on the following: Rigid nonmetallic conduit PVC schedule 40 and 80 are not allowed to be field threaded, according the UL white book, under (DZYR), it states; "PVC conduit is designed for connection to couplings, fittings and boxes by the use of a solvent-type cement." So it is legal to use cement to attach a threaded fitting to the conduit. Cite section 110.4(B) for violations.
Click to expand...
But it doesn't specifically say it's not designed to be threaded. It can be designed for both applications. Now if it said it was ONLY designed for connection to couplings, fittings...etc, then I could buy into it being not allowed.
 
Re: RNC Threading

Originally posted by sandsnow:
Along the same lines, the Code mentions factory threads for EMT are permitted (if I remember correctly).
Anyone ever used it or seen ??
Click to expand...
I install some fire alarm radio master box antennas that come with internally threaded 3/4" EMT.
 
Re: RNC Threading

Originally posted by paul:
But it doesn't specifically say it's not designed to be threaded. It can be designed for both applications. Now if it said it was ONLY designed for connection to couplings, fittings...etc, then I could buy into it being not allowed.
Click to expand...
Paul IMO you are not familiar with the UL white book.

It is not the same as the NEC, (a permissive document) when the UL white book states "PVC conduit is designed for connection to couplings, fittings and boxes by the use of a solvent-type cement." that is it, no other options.
 
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