EMT STRAPING

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Gmack,
I don't think it makes any difference what the material is, the code wording is the same for all of the raceways...you must support it within 36" of each conduit termination. I agree that the things you talk about in your post are not normally supported, and I think that is common sense, however I don't know of any code rule that permits those installations.
Don
 
Gmack, I disagree. A nipple can be any short piece of conduit. EMT, RNC, RMC, etc. In fact the NEC uses the term in 310.15(B)(2) Exception 3. This would apply to any type of conduit nipple.


310.15(B)(2) Exception No. 3: Derating factors shall not apply to conductors in nipples having a length not exceeding 600 mm (24 in.).
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OK, when you order nipples from a supply,

How do they ship them?

EMT? I have never seen one.

Look in Art 100 or any other Article. The NEC does not define what a nipple is.

However, in all the photo examples of the NEC Hanbook under 315, which shows several cabinet to meter socket configurations, no supports are there between cabinets/ disconnects/ meter sockets [shown] on or for nipples. BTW, nor are there "connectors with a support between cabinets.

The Handbook shows in detail, "supports" otherwise.
 
Iwire, your using "raceway" not nipple language. The code you cited does not refer to nipples. And it does not mention anything about supports. It is a conduit fill to derating factor code issue.

Why would you apply this to a nipple support? Even if EMT could be cited as a nipple here. Which it cannot.
 
Gmack I agree with you on the not supporting nipples, but a nipple can be any short piece of conduit. Just because you order a nipple from the supply house and they send you a piece of RMC does not mean that nipples are made of only threaded conduit.
 
Gmack said:
Iwire, your using "raceway" not nipple language. The code you cited does not refer to nipples.
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It does not?

310.15(B)(2) Exception No. 3: Derating factors shall not apply to conductors in nipples having a length not exceeding 600 mm (24 in.).
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It sure looks like it does o me.


Gmack said:
Why would you apply this to a nipple support?
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To point out that nipple is a generic term and does not specifically mean threaded nipples.


Gmack said:
Even if EMT could be cited as a nipple here. Which it cannot.
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Here you are mistaken, 310.15(B)(2) Exception No. 3 applies to EMT, PVC as well as RMC and IMC.
 
Gmack said:
Iwire, can you define a nipple? With NEC language?
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Can you? :lol:

The point is a the NEC does not define a nipple as it is a common term that describes a 'short hunk a pipe'

Check this out directly from the NEC Chapter 9 Notes to tables.

Note (4)Where conduit or tubing nipples having a maximum length not to exceed 600 mm (24 in.) are installed between boxes, cabinets, and similar enclosures, the nipples shall be permitted to be filled to 60 percent of their total cross-sectional area, and 310.15(B)(2)(a) adjustment factors need not apply to this condition.
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It seems the NEC also believes like Trevor and I that a nipple can either be a conduit nipple or a tubing (EMT) nipple.


Gmack said:
Then, if you can cite where it "shall be" supported?
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I never said a conduit nipple shall be supported,

I do agree with Don that per the letter of the code EMT nipples shall be supported.

The fact that it is a nipple does not mean it is not also an EMT raceway.

That said I often do not support short sections of EMT between enclosures.
 
Ryan had a proposal on this subject.

I'm curious how it fared.

Ryan???

If I have a 35 inch or less piece of EMT between enclosures, the Code requires it to be supported.

In reality, I believe short sections can be just fine left unsupported.

What do you think some of the factors should be in deciding when a strap would be required??

Given a 24 inch piece of EMT, do you think a competent electrician could get an offset on each end?? With a conventional hand bender???
 
Dang did i start all this :shock: :eek: :lol: :p
All i was after is hopes that maybe i missed something like an exception that allowed it.Seems like there needs to be an exception.What gets me is it is good to go for actually 5 feet if 1 piece and no place to strap.Why would an MC connecter be allowed to support a whip for 6 feet but something solid like EMT can't even travel 3 inches without a strap.Yes the inspector will probably let it slide but i should not need ask him or count on it.NEC has failed again.
 
Inspector was by today and i showed him one of the runs i had made without straping.He didnt say it was legal but indicated he didnt care.20 minutes we walked 10 units all perfect sept for a missing ground screw.Dang they are good at finding small stuff :lol:
 
Given a 24 inch piece of EMT, do you think a competent electrician could get an offset on each end?? With a conventional hand bender???

Larry, yes I do, but in most cases I don't see any point in it. Most Inspectors & electricians use common sense in this area.

Aw shucks! I just reread quote. I was thinking given a 5' foot piece I could put in offsets and cut it off to 24".
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dlhoule said:
Given a 24 inch piece of EMT, do you think a competent electrician could get an offset on each end?? With a conventional hand bender???

Larry, yes I do, but in most cases I don't see any point in it. Most Inspectors & electricians use common sense in this area.

Aw shucks! I just reread quote. I was thinking given a 5' foot piece I could put in offsets and cut it off to 24".
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It can be done but i would just use my greenlee offset bender.Much faster and better looking matched offsets :D
 
358.30(A) says that it shall be securely fastened within 3'. Within means less than 36". If it is 13" long, it is supposed to be secured.

358.30(A)(1) says that if there is not structural members to secure to, an unbroken length can be up to 5' without support.
 
If there's no room for offsets (which in my opinion are overrated anyway), use a Mineralac strap or two. They match most KO openings.

These dudes:

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Jim W in Tampa said:
dlhoule said:
Given a 24 inch piece of EMT, do you think a competent electrician could get an offset on each end?? With a conventional hand bender???

Larry, yes I do, but in most cases I don't see any point in it. Most Inspectors & electricians use common sense in this area.

Aw shucks! I just reread quote. I was thinking given a 5' foot piece I could put in offsets and cut it off to 24".
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Click to expand...

It can be done but i would just use my greenlee offset bender.Much faster and better looking matched offsets :D
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All true.

I have no problem using common sense here as well.

I thought maybe a Code proposal is in order here.

Ryan had mentioned making one. Maybe there will be an opportunity for comments to support his proposal.

It seemed input was in order along those lines. We don't ask for support on 2 inch nipple between enclosures. Obviously.

When does a type of conduit or tubing change from Nipple to Raceway???

That's the $64,000 question!!!
 
What gets me upset is that they are saying 5 feet would be ok if there was nothing to strap to but 4 inches between 2 connecters would be a violation.I do understand they would not want me running 10 feet between boxes and saying my connecter is the support.This is just a poorly written code.NEC often uses a hundred words to try and say something but then fails anyways.A law degree should be a must for electricians. :wink:
 
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