Bundling of NM cable- perspective?

[sw_ross]

Regarding residential wiring, I've worked with a couple of different EC's that had different perspective's on what was/is allowed regarding "grouping" of NM cables. Especially as you start pulling HR's through I-joists in the bsmt towards the panel.

Specifically, one EC had an SOP to drill a series of 1 1/2" holes spaced about 6 inches apart through the joists and pull a bunch of hr's through the holes (as well as interconnecting various circuits with the holes when it was convenient) heading towards the panel. These joists were usually on 16" center's. Usually we pulled hr's through the holes until there was a risk of damaging the cables (~6-7 cables). He didn't consider this bundling because they weren't in a raceway.

Another EC I worked with had a general practice of no more than 3-4 cables through a drilled hole, trying to maintain/follow the "no more than 3 ccc's"- especially through drilled holes that were later filled with expansion foam (which I can understand). This practice resulted in a LOT more drilled holes in a house.

Please give me your opinions/perspectives on these practices.
Thanks!

 

[MasterTheNEC]

The EC that said this lost all credibility. "He didn't consider this bundling because they weren't in a raceway."

Clearly the EC doesn't own an NEC or read sections 310.15(B)(3)(a) and 334.80 when making their statements.

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[Ponchik]

You don't need conduit to be considered bundled together. If the cable are together for more than 24" then derating must take place. However, if you separate them a bit then they are not bundled any more. The NEC does not define how many inches apart is considered proper separation.

For me both scenarios you mentioned will work fine.

 

[infinity]

This concept of bundling is just a matter of opinion, IMO cables run through holes of joists 16" on center are not bundled for more than 24", cable tie them together then they're bundled. Either way the NEC is silent as to the definition. The condition of filling the holes with fire or draft stop matter is clear, adjustment factors do need to be applied so for me nothing in the hole no adjustment required.

 

[don_resqcapt19]

I agree with Rob...this is not a clear cut issue. It is subject to the opinion of your local inspection authority.
[/quote]310.15(B)(3)(a) ...or multiconductor cables are installed without maintaining spacing for a continuous length longer than 600 mm (24 in.) and are not installed in raceways, ...[/quote]

 

[MasterTheNEC]

LOL....OK..just pull the cables apart when they are between studs and no longer bundled. If you want the root of the two EC's opinions then again read 310.15 (B)(3)(a) and 334.80.

Why not ask your local AHJ what their opinion is if you would like to as the others and play semantic with them.

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