ECN Forum Forums Code Related Discussion NEC & other Code issues What do you guys think?

When you are talking about derating and bundled cables, neatness is your enemy. You really want them to be very disorganized between holes. You want the "inside" cable in hole "A" to be outside in hole "B". I really don't start thinking about derating unless I see a very pretty bundle with carefully aligned cable bundles. The cables in the middle are cooking. If you fan them out between holes they can breathe.
I have seen inspectors make the same demand in large panels that were a thing of beauty but they had big bundles of THHN going more than 24". The EC almost cried when he had to cut those tywraps and spread the wires out, "messing up" that panel.

The I joists I've seen have a prepunched hole every 18 inches or so. Kinda like a KO, hit it with a hammer and out pops the wooden slug.

My experience about the KO's is that I have never seen a framer line up the TGI's so that the KO's could be used in a neat and workmanship like manner. Usually staggered (because of length cutting at the lumber yards for delivery), or some tipped upside down in relation to the others. Usually end up drilling anyway. Here in Wisconsin most heating contractors prefer wiring that is installed first to be closer to the bottom of the TGI. For a smaller hole of 2", I think the books that come attached to some of the TGI's usually say within 1/2 inch of bottom support ridge (or whatever they are called). Holes must be twice the diameter appart for most requirements that I have read. On bundling, here in Wisconsin there is an adoption to the code with exclusions like AFCI for bedrooms, and for bundling of romex. Check your state codes?

Earl:


Yes and the Definition of "Bundled" comes from Article 520, and not from 100.

Good canidate for 2008 proposal.

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[This message has been edited by Joe Tedesco (edited 12-24-2004).]

Romy: welcome to ECN fourm here ,

I am in wisconsin also and i am not far from your area in fact about 15 min will ring the bell to ya.

anyway yes Wisconsin will adopt new code but for AFCI it will be enfored but i havent heard the final word yet, but they should inform me anytime soon about the state code along with few additional change along for new code cycle.


anyway for the wooden I beam type that is very tricky part i did see and some have prepunched holes but majorty of my time i dont like to use prepunched hole due what you and few other guys described and it show poor workmanship and waste extra unneed materals and time but i know Ryan [ the electrical/ building inspector ] do show up here from time to time and i think he have a link somewhere we did look it back sometime ago related with the wooden I beams


merci, marc

I wish I had the instructions for the I joists. I'd guess those KOs are placed in the joists where the manufacturer wants. Seems to me that thats more important than neat and workman like?

Walrus,

The concept is great. Problem is the TGI floor joist come in longer lengths to the lumber yard than most customers need. They at the lumber yard then cut them for size with a chain saw type tool. This can put the holes back and forth in a wire run as much as eight inches or so. Add to that every time one is used in a different side up to the floor, then the vertical alignment doesn't line up with the run either. I have seen some installations where they were used anyway, and it didn't look good. Besides the look, think about making the 3rd, 4th, and 5th pulls through these staggard holes. Like pulling romex with someone on the other end holding it back for every turn. These holes are generally close to the center of the joist and the heating men have a hard time putting their six inch ducts perpendicular to these cable runs. Sometimes pulling a little slack from both dirrections works for them, but with these misaligned holes there is no pulling of slack without a come along.

As for the Wisconsin code being adopted and enforced, it ususally takes about one year for all the suits to make up their minds on all the details and send out their com. 16 State adoption to the NEC. In the time they are deciding, we continue to go by the previous accepted code. The rumors that I have heard have it that the suits have still not come to terms with the Arc Fault Circuit Interupters, especially with all the new reports of them not working as they should.

Joe
I am just wondering if the 520.2 definition of bundling can be used as an enforcement type of definition elsewhere in the NEC, as this definition is not in Art 100?

Like you, I see a 2008 NEC proposal for this .

Pierre

Bundled.
Cables or conductors that are physically tied, wrapped, taped or otherwise periodically bound together.....


Otherwise periodically bound together???? Couldn't a inspector consider joists as periodically bound?

My standard is if they get fanned out between points where they are together.
The point is you can't have 24 continuous inches without a chance to breathe. The more air the better.