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Joined: Apr 2002
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Kjay: I've given this thread thought, read the responses, & gave more thought.
I can't pin an article that I could cite.
Talking with a few inspectors & ECs at a CEU class I did Tuesday, the inspectors had no ideas, and the consensus from the ECs was split. The split was 50% said 'stupidity', the other group said 'it's not something they do'. Now, that they may be aware it's not citable, I'm waiting to see IF anyone tries it.
John
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Joined: Aug 2006
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I have asked this question from a local inspector and he hasn't been able to cite a section.
Be kind to your neighbor, he knows where you live
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Joined: Apr 2002
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Niko: I strongly doubt that any NEC Article could be cited. As long as fill capacity is not exceeded, there is no article to cite.
John
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Niko: I strongly doubt that any NEC Article could be cited. As long as fill capacity is not exceeded, there is no article to cite.
He tried, 310.15, 310.4 and 300.5 but none apply. i just wanted to see if he had anything to say. I will bring it up on my next IAEI meeting.
Last edited by Niko; 11/09/10 10:34 PM. Reason: add more comment
Be kind to your neighbor, he knows where you live
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Joined: Feb 2002
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Greg,
Is the EMT outside? Then you can cite, no RX is allowed in a wet location.
If the EMT is inside, you can ask the EC for a UL listing for approved use of the RX inside of EMT.
Will you have to derate the conductors because of a cable installed inside of EMT.
I would use an EMT/PVC to protect a piece of cable when running through a floor or along a wall, etc. However my rule of thumb was any length of pipe 10' or less could be used for physical protection, but not over 10'. Then we would just run pipe.
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Joined: Apr 2002
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Harold:
To continue this debate, I reply to your comments (IMHO)
Yes, if it is outside then it's a wet location, but the OP did not go there.
Going the UL route may be extreme, but it's a thought.
Derating, as the OP statement is not an issue I think. Greg did not mention any info leaning that way.
Your 10' rule of thumb would also be a tough thing to cite, as I'm not aware of any dimensions within the NEC for physical protection.
John
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Joined: Jul 2004
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Inside I don't think you can get any code traction on increased heat, derating is only based on the number of current carrying conductors. It doesn't matter if it is a bundle of wire, zip tied together, a cable, 1/2" PVC or 4" RMC) I also don't find a prohibition of cables in raceways. In fact note 9 to table 1 in chapter 9 implies you can put cables in raceways and gives you the way to compute fill. (9) A multiconductor cable or flexible cord of two or more conductors shall be treated as a single conductor for calculating percentage conduit fill area. For cables that have elliptical cross sections, the cross-sectional area calculation shall be based on using the major diameter of the ellipse as a circle diameter. Note 2 makes it clear note 9 is not talking about short sections of conduit used for physical protection. (2) Table 1 applies only to complete conduit or tubing systems and is not intended to apply to sections of conduit or tubing used to protect exposed wiring from physical damage.
Greg Fretwell
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Joined: May 2005
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BTW, They changed the derating tables in 2011.
It used to be based on the number of 'current-carrying conductors' in a raceway. They deleted the phrase 'current-carrying', so conductor sizing will soon be getting a bit trickier.
Ghost307
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John,
I guess my 10' rule is just a rule of thumb that can't be quoted from the NEC. As Greg said, the code does allow a "Short piece" of conduit for protection to be allowed. Just how short is short? It would up to the AHJ as to make that call.
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Joined: Apr 2002
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Harold: I know what you mean, and the intent of what you mean. Unfortunatley, I know of an instance of the Board of Appeals not being to appreciative of not having a code article to cite.
Standard trade practices, and workmanlike manner aside, some people have an axe to grind, and they waste their time going to the mat, or the ends of the earth.
The above comments are my opinions, and are not intended for any individuals, either ECs or AHJs.
John
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