PVC

[alan mcneil]

I have read the articles pertaining to "ENT" and it is not clear at all to me if it is legal to use it in some areas.
From my understanding in the past, PVC (polyvynalchloride)plastic pipe should not be used in places of assembly of more than 100 persons... and the code book listed some of the places, and added that restrictions for its use was "not limited to that list of places.
Now it seems that the wording has been changed and the exeptions seem to circumnavigate the common sense reasons for not using PVC.
When this stuff burns it emits deadly gas and will kill you.

 

[don_resqcapt19]

Re: PVC

Alan,
Look at 518.4. In general ENT and rigid nonmetallic conduit are not permitted in places of assembly, but in any part of the structure that is not required to be of "rated" construction, these wiring methods are acceptable. The "rated" construction would be prescribed by a building code and not by the NEC.

As far as it being "common sense" to restrict these wiring methods in places of assembly, I'm not so sure. The very small amount of these materials that would be installed within the building as compared to the amount of furnishings (carpet, furniture, building finishes, ect) with similar toxic smoke properties provides little additional risk.
Don

 

[alan mcneil]

Re: PVC

Hotel fire in Los Vegas about 15 years ago had pvc pipe and contributed to the cause of deaths in that fire.
I forget the particulars of that fire.

My concern is that with building inspections services being cut back due to lack of funding, and competition among contractors this could happen again.

 

[don_resqcapt19]

Re: PVC

Alan,
If you are referring to the MGM Grand fire of November, 1980, there is nothing in the Clark County Fire Department, MGM Grand Hotel Fire Investigation Report to indicate that any appreciable amount of toxic smoke was produced by plastic piping used in the construction of the building. The report indicates that the conduit used in this structure was electrical metallic tubing. The fire report does indicate that this fire was of electrical orgin, but that the smoke was produced by, plastic ornmental fixtures, wall coverings, furniture and common combustibles located in the area. There is no mention of smoke produced by nonmetallic piping of any type used in the construction of the building. There is a statement that some 12" ABS drain piping above the ceiling area did at some fuel to the fire. The evidence in the report is clear that most of the smoke was produced by the burning finishes of the building.
Don

[ February 23, 2003, 12:32 PM: Message edited by: don_resqcapt19 ]

 

[alan mcneil]

Re: PVC

Yes Don,
I was thinking of the MGM fire, I stand corrected.
You are very informative and helpful, thank you for your help.
More stars for Don.

 

[landelectric]

Re: PVC

E.N.T. has been around for years yet, I have never installed it and I have never known anyone who has installed it, very strange.

It seems like a good idea, and I have always kept it in mind for use in some future installation, but never have.

One issue, is the 360 degree max. bend rule. As with metalic flex, it's easy to get over the limit of bends in a hurry without noticing.
AC / MC is a better choice for that reason alone.

Home Depot always has it in stock (sometimes without the required fittings) I think Carlon is trying to dump the stuff on unsuspecting screw it yourselfers

 

[iwire]

Re: PVC

Same here, never seem to think of it when I could have used it. A coworker that used it said it was hard to get the wires in but I bet he exceed 360 in bends, easy to do as you pointed out.

Bob

 

[luke warmwater]

Re: PVC

I used to work at H.D.part time and that stuff flew out of there. It seems that people use the stuff for just about everything that it wasn't intended or listed for. The most common question i would get was "can it be used underground?" No. Then 10 minutes later, the person would be checking out with it.
I know that the stuff is there, but never seem to think of using it either. I recall seeing it used on one of the 'Home' shows on TV a few years ago. It was used in wiring a whole house.
I also believe that Carlon had it listed to be used with their pvc fittings along with the snap-on ENT fittings. I'm not certain, I'll try to find it on their web site. Todd

 

[landelectric]

Re: PVC

Hi Todd,

It's interesting to hear about this issue from the perspective of a Home Depot employee.
I often buy supplys at HD and overhear questions from D.I.Yourselfers to clerks, it's soooo scarry!
People buying Service Equipment and asking questions like "what size wire should I use ?" Shopping carts full of supplies that you just know don't go together ! comments like; "give me some good HEAVY wire" It's hard to keep from jumping in with advice like; "what in the HELL are you DOING MORON !!!! " One of the most common issues lately seems to be the 4W vs. 3W dryer and range issues, people want adapters or some way to defeat rules. I enjoy answering questions for people but when they don't even have the most basic understanding of electrical wiring, where do you begin ??

What's the most bizare customer question you ever
had ? and did you ever just tell 'em to call an electrician ?

Eric Land

 

[landelectric]

Re: PVC

I just noticed that the temp rating of ENT is
50 C. per 362.12 That is a major limitation and may explain why it hasn't taken off in the professional marketplace.

If I was CARLON, I'd be trying to sell it to D.I. yourselfers for direct burial too !

Eric Land

[ February 24, 2003, 01:07 PM: Message edited by: landelectric ]

 

[Nick]

Re: PVC

Landelectric,
Where did you see it was rate for 50DegC? This document states it is rated for 90Deg C conductors.
I haven?t used it in a while but it is used very extensively in poured in place structures. I have done a poured in place 4 story student services building and a couple of parking structures with it in the slabs. It?s not too bad but watch out for long runs! Like stated here it can be easy to exceed maximum bends. On a long run weaving in and out of rebar you can create a nightmare for yourself.

 

[landelectric]

Re: PVC

362.12 says (3) says 50c unless listed otherwise.

So your saying it's listed otherwise at 90c

I'll bet it would be great for pre-cast in and out of rebar and all........then just call the ROTO-ROOTER (tm) guy to do the pull while I go skiing !

 

[curt swartz]

Re: PVC

362.12(3) Where subject to ambient temperatures in excess of 50C (122F) unless listed otherwise.

This would limit the exterior temperature not the conductor temperatures.

As Nick said ENT can come in handy for slab work. We also use it extend PVC stubs up to receptacle and switch boxes in walls to avoid bending short sections of PVC to line up with the KO's in the boxes. ENT is designed and listed to be used with standard PVC fittings in addition to the snap in fittings.

 

[luke warmwater]

Re: PVC

Eric, I worked there part time for 2 1/2 years. They gave me a '30 day to comply' order to work more hours. Between running my business, wife, kids, other interests, I left. I don't think that I could pinpoint one as most bizarre. Here's some:
-give me the 1/2 inch gal. ground rod for the service
-why don't you have a double male ended extention cord
-why don't you have a straight to twistlock adapter for my pool(I actually had one lying around made by Hubble-I don't know what happened to it, but it wasn't for a pool application)
-The 3-prong to 4-prong dryer and range adapters would be top sellers if they had such a thing
-give me ser and pvc to run underground to my shed and also coax and phone wire
-I don't need that(transfer switch), I'll hook up the generator to a breaker in the panel
-Well my friend told me that I could do it like this
-That's not what the guy in Plumbing Dept. said
-Can I have your number
I would recommend an electrician as much as possible. It was against policy to give out names so I would refer them to the phone book. If I knew an electrician that was near, I would say, "hey, you're an electrician aren't you" and sometimes that would start them with a conversation. I very rarely let people know that I was a licensed electrician unless they asked me. Other employees would send customers to me with questions and I would feel them out. If I didn't think that they had a clue, I wouldn't try to elaborate very much. I don't have anyting against D.I.Y.'s but some things just shouldn't be done by them. Sometimes I would even say 'I might be qualified to tell you, but that doesn't mean that you're qualified to understand'. They wouldn't like it, and I would explain liability issues.
What was more bizarre are the things that would happen there. I'm surprised that I haven't seen a book out yet.
I had one professional(not a license holder) tell me in front of a customer that I was going to 'get someone hurt' when I told the customer he didn't need 20amp GFCI and duplex receptacles in his kitchen. When I tried to explain to both of them about feed-through capacity, said professional told me to 'show him on the device where it sais feed-thru'. I told him that it's in the Code but I'm not allowed to quote Code to customers but if he would like to attend one of my PK classes I would be more than happy to explain it to him. He walked away.
I am guilty of this myself. When I go into H.D. or Lowes, I tend to not pay attention to the employees. There probably are some that have some knowledge, and maybe some who are licensed or retired electricians. But I too have heard some of these guys give very scary and wrong advice. Todd

 

[vanwalker]

Re: PVC

ent is a good product, easy to work with and should be used according to the manu.spec and nec.
my two cents ,after many thousands of feet,do not use 1/2" very hard to pull, not worth time and effort. have nothing else bad to say and would use it again. GEO

 

[iwire]

Re: PVC

I was at Home Depot recently picking up some forgotten stock and overheard a customer explaining how he just bought a new dryer and it keeps tripping the breaker which was in his hand I could see that it was a 2 pole 30 and he was asking the store clerk for a bigger breaker, to his credit the clerk tried to explain that was not the answer but the customer had decided already that was what he wanted to do.

I did not get involved because how do you explain to someone who does not know what your talking about.

Probably a tough job working at HD I would not last long.
Bob

 

[landelectric]

Re: PVC

Way interesting Todd, The new HD is going to open here in Durango, CO on Thursday. Durango made 'em put fancy stonework and timberframing on the front and sides of the building, it looks great. Not just an orange box.

Ok I'm convinced, I'll try the ENT. It would be good for data-com use anyway. I noticed they are making it in orange color with backless boxes to match for data.

 

[luke warmwater]

Re: PVC

Eric, that's a good idea. It would also give a way to later get another phone wire to the attic from basement. Especially if someone wants network wires added.

 

[rb]

Re: PVC

Todd,

The funniest thing I ever saw at the depot was a guy buying an amp clamp (about $50.00) so he could trouble shoot an open receptacle circuit at his house. I told him that as soon as he could get it to read anything other than zero the problem was solved.

 

[luke warmwater]

Re: PVC

The funniest thing that I ever saw (true story) is a guy taking a leak right in the middle of the lighting aisle. I was glad that I had my own aisle assignment to take care of.