Hey guys whats everyone`s interp of 352.46 then refer to 300.4f Here`s the deal wired mobil home pvc male adapter sch 80 pvc well I failed because no bushings on the pvc male adapters.Are they required in this situation? Using 4/0 quad cable direct burial. Thanks waiting for inspector to call us now as he left no reference yesterday.

PVC may be non-conductive, but its edges are still sharp enough to damage insulation.
I think that's the reason behind 300.5H.
BTW, I always call for metallic elbows in underground PVC runs because the rope that pulls in the conductors can grind an edge in a PVC elbow during a tough pull. I've had cables fail to each other on an U/G feeder for just that reason before I adopted that little trick.

Hey no rope here. Dug 10 ft ditch sch 80 down from box to proper depth direct burial cables to other end pvc to box slide wires in. But pvc fittings are beveled smooth and I don`t see how they can damage the wiring.

Did he tell you exactly what point he was concerned with? Yes, the fittings are smooth, but when you cut a piece to length, the end isn't so smooth. Is there a point where wires exit through such an opening?

You might be able to make a case that the burred end of a PVC pipe you cut with a chain saw could damage conductors but if this is the threaded end of a PVC male adapter, I don't see the issue. They are as smooth as the edges of a plastic bushing.
Both are mass produced injection molded plastic. The chance of a flaw in the process that leaves a rough edge is about the same for either.

I am very doubtful that a PVC male adaptor provides a "smoothly rounded insulated surface" as discribed in 300.4(F) and would red tag the job without even hesitating. I'm comparing it to a female adaptor with a chase nipple or a threaded hub or boss that is an integral part of an enclousure. Sorry gentlemen.

OK "the code" has spoken, (we should fail it)now has anyone actually seen a conductor damaged by a PVC fitting?

I hate to step in this one,,,


unforetally yes i did see few conductors got damaged by male termal adpator espcally after hard pull i did nick few of them [ugh !! ]

but the code required the bushing on the male adpator it been like that way for pretty long time i was not sure when it was enforeced.

I think it was debated before related with mobile home service hook up and kinda pretty common to get red flagged from this one if not carefull with bushing

Merci, Marc

I think that a male adapter requires a bushing based on this section.
Don

I looked at a few fittings and I agree. For some reason <Carlon> makes the edge sharper than it has to be, perhaps to sell more bushings. It would be quite easy to make the edge rounded to provide "equivilent protection"

I use them when doing a PCV service riser, but the local POCO doesn't.

The cost of a plastic bushing ($0.50 -.75?) is worth the peace of mind.

OK I respectfully disagree with some of you based on "a bushing or adapter " In my opinion here`s the deal With a metal fitting with smooth rounded edges I need no bushing unless I go over 4awg then 300.4f applies.Well a pvc male adapter has smooth rounded edges and is insulated.And quite frankly if someone bends a conductor over a 2 inch m/a and cuts a wire thet have more serious violations than a bushing.These wires come strait out of pipe to lugs and hardly touch the pipe. The problem is not the bushings its actually the 50.00 reinspect fee. For what is a questionable violation.Is an pvc Male adapter insulated(yes) Is it manufactured with a smooth rounded edge (yes)Did I damage any conductors in the pull (no)Is it likely in any form future damage will occur(no)Did I fail the inspection (YES)Will I use bushings in this application next time (YES)I think if I were to go to judge Wapner he`d agree based on the wording of the code I`m minimally compliant but compliant none the less. And guys I rarely fail inspections I feel the code is min and I rarely fall into the min catagory.Goerge and Don do you really feel that strong about it being a violation based on the wording of the code?

I see your point. The code does say "unless the box, fitting, or enclosure design provides equivalent protection." (352.46)
and 300.4(f) says "protected by a substantial fitting providing a smoothly rounded insulating surface."

I think these articles are really talking about protecting metal fittings but that is not what it says


If the manufacturer would simply make the end of the PVC male adapter rounder there wouldn't really be an issue IMHO but when I looked at the larger sizes I have from Carlon they make the edges very square. Being the skeptic I am I think it is on purpose so they can sell more bushings.

The wording of the Code does not distinguish between metal and non metal raceways & fittings. It is a Code violation.
The lack of connectors and bushings is most commonly seen on large service panels with bottom feeds.
I have not seen conductor damage with PVC conduit that didn't have the bushings and I have looked at a lot of services.
I have heard that bushings can be cut and reglued if the wires have already been pulled and the inspector won't know.
Alan--(Inspector)

I don't agree with the second statement. The box adapters shown on the first page of this document have smooth rounded edges.
Don

Well this just in: The inspector agrees somewhat with my conclusions. He realizes I always call for clarifications on questionable interpitations.So we`ve agreed I`ll give the bushings he`ll give the sticker I keep the 50.00 reinspection fee.I called State board and they also agreed that in the wording the male adapter would seem to sufice with pvc but it leaves some interpitation and they wouldn`t over rule the local inspector.I never mentioned any names or location only what county I was in so I thanked the inspector for my 50.00.All is well.
PS I left a bushing on his desk as we walked out of the office

Here's my problem, we've found in the code that we need a bushing on installations with conductors #4 AWG and larger so now your asking me to selectively enforce the code because your job appearently went in without damaging the conductors. You've already said that from now on you'll use bushings. I'm glad the inspector was a fair individual and I will be the first to admit that inspectors are somewhat like people. They are all different, we'll leave it at that. So now I approve your job because the conductors were not damaged and your competition learns about this and I ask your competition to install bushings and he says "You didn't make Reel-Break install bushings, how come I have too?" As inspectors we have to be consistent or we're doomed as inspectors. We may be consistently wrong, but we're consistent. Put the bushings in gentlemen, don't ask me to break the law.

George I still respectfully disagree with your interitation.I think the artical 300.4f is for metal conductors not a pvc plastic insulated smooth rounded male adapter.But apparently you totally didn`t understand my post I did go back and install the bushings. He didn`t make me pay the re inspection fee of 50.00.I can`t see how you read 300.4f and don`t think a plastic male adapter is not a insulating fitting with smooth rounded edges.Goerge I`d hope you also could straddle the fence and see this is really not a clear issue due to the nature of wording.I`m not saying I`m correct but I`m not wrong if you read the words look at the pvc male adapter. Well I`m moving on now no need to keep this up.Do you at least agree reading the code how I could make the assumption the male adapter was ok.If so I`d hope you`d be as professional as my inspector was.We both win He got the bushing I`m not out 50.00 for a honest easily made assumption that could very well could been made by anyone.Reading the words of the code artical.

I do thank you guys for the feed back it makes us all better.And a diagreement is mearly a different opinion on the same matter with 2 veiw points.Thanks again Mike

George 300.4(F) never mentions a bushing, that is all what an inspector decides is a "protected by a substantial fitting providing a smoothly rounded insulating surface".
If someone took a minute to "smooth" the edge on a PVC male adapter fitting I am not sure how you could fail them using anything but opinion. The code doesn't back you up. I will say the ones I saw right out of the box do not have a smoothly rounded edge. It is a sharp 90 degree angle. Since the radius of that "rounded" edge is not defined, anything that knocked the point off would be round.

Read it again Greg-the part after the exception talks about bushings. Hey - We're talking what 50 cents? I can't round the surface of a male adaptor then argue with some narrow minded inspector who wants a reinspect fee for 50 cents. What if I used an insuliner (spelling) when I foget or don't have a bushing?

And another thing 352.46 does spell out a Bushing or adaptor. But this could be subject to the discretion of the AHJ I guess.

[This message has been edited by George Little (edited 05-12-2006).]

I'm not at work but I believe the 92 rop has an interpertation from the CMP stating PVC male adaptors do not require a bushing. sorry I can not get the actual reference but email me if you wish I will search on monday

charlie

I don't see how anyone could call the (maybe smooth) end of a male adapter "rounded".
Install the bushing, and call it a nice looking installation.

charlie,
I didn't find any thing in the 92TCR, but did find one in the 95ROP, however I don't think it is a clear cut statement that PVC male adapters do not require bushings.
The panel statement on proposal 9-93 said:
"The code already allows for nonmetallic conduit termination fittings with rounded edges without additional bushings".
This does not clearly apply to male adapters, because they don't really have rounded edges. It is my opinion that the only PVC fittings that have rounded edges are the box termination fitting or an end bell.
Don

[This message has been edited by resqcapt19 (edited 05-13-2006).]

It is clear this is one of those things that is answered by "it is only a half buck so do it" instead of logic at code language.

BTW if this "smooth rounded edge" is so important, why doesn't it extend to the inside edge of a conduit body entry?
I have some Carlon conduit bodies here and I see very little difference between the edge of a male adapter entry and the conduit body entry. Certainly not enough difference to justify extra protection for one and not the other.

Lets not forget the bushing is supposed to be installed before the conductors are pulled. Not after the conductors are pulled and you say... see the PVC is not damaged.

Like Merci Mark, I have seen PVC damaged during pulls, that also caused damage to the conductors.

I guess that is technically true but I seldom install bushing before the pull on any raceway type.

I may install them on the feed end but never on the pull end.

If you install the bushing on the pull end it will either be ruined by the rope or broken by the wire 'head' coming into the enclosure.

There is also the fact that when using pulling equipment a bushing prevents connecting the puller to the raceway.

Bob

I do the same thing, but technically I suppose it is not code compliant to put the busing on after wires are pulled. Besides that, I think I have seen more wire damaged by poorly made joints than I have lack of bushing on pulling end of run (RNC or RMC).

Unless you have a bad pulling angle, you won't damage wires on pulling end and if you are going into bottom of box or whatever with wires continuing on up to top of box for termination you are not likely to cause any damage with or without a bushing.

Sorry I have been away from this topic, I agree with Don regarding the issue of smooth Vs not smooth, but I posed this same question to a manufacture and I received this proposal and panel statement to support the absence of insulating bushings on such installations. As some one mentioned it may be an issue of interpretation.
Charlie