How many romex wires (12/2, 14/2, 12/3, 14/3) can you staple by code?

Can you staple 3 12/2 wires using one staple?
Can you staple 3 14/2 wires using one staple.

Thanks

I've only seen single and dual staples. I would expect if you wanted more, install conduit.

Code does not state how the cable shall be supported, code refers to the UL listing of a product. The product must be rated or listed to handle more than one cable.

Here is an excerpt from a popular brand of staples:

http://www.brisconelectric.com/STAPLES.htm


SN 150 I B (NM - UF) - Insulated - 1-1/2" long 1/2" wide
Wt. per M Unit Qty. Std Pkg UPC code
9 100 5000 780227-75027
9 250 2500 780227-75028
9 3000 KEG 780227-75026

NON-METALLIC SHEATHED 14/2 through 10/3 (One Cable)
14/2 through 12/3 (Two Cables)

UNDERGROUND FEEDER
14/2 and 12/2 (One Cable)
14/2 and 12/2 (Two Cables)
ZINC PLATED
X-LONG



Another product is called a Stacker made by 3M, found here:
http://multimedia.mmm.com/mws/mediaw...666B4UCOrrrrQ-

These are only good for cables attached to vertical members, such as studs. For horizontal joists, only staples supporting two cables is available.

Also watch out for de-rating of wires if you're bundling lots together. Of the top of my head, as soon as you have three or more cables bundled together, you have to start increasing the wire gauge or decreasing the potential current through them.

Correct on the derating issue,dmatos. I almost mentioned it, but thought why give the OP any ideas. But since you brought it up,bundling cables needs special consideration.

Derating is done by adding up the total amount of current carrying conductors. With the typical two and three wire cables , plus the ground each wire not a ground is a current carrying conductor. To start, for example, when 4-6 current carrying wires are bundled, and this happens just with two 2 wire cables, must derated the circuits by 80%. The derating percent lowers as the amount of wires increase.

The method of derating is done by one of two ways. Either increase the size wire, or reduce the size/rating of the overcurrent protection device(fuse or circuit breaker).

Derating can get a bit complicated, as the ampacity to start the calculations of the wire begins with the type of insulation.

Better to not bundle any cables and not have to deal with derating at all.

What about putting multiple cables through holes drilled in framing members? Is this considered bundling and subject to derating?

In the Ontario electrical code, it's only considered bundling if the wires are in contact with each other for more than 24 inches. If you've got a lot to put through a single framing hole, you can get special spreaders to space them out between the framing members, and you don't have to derate.

Yes dmatos, good point,

The same is here in the US. It can be tedious but very possible and allowed.

After doing some calculations, it seems to me that it doesn't mater if you have to derate until you get into a lot of cables (5+ for #12).

For example, say you have 4 12-2's bundled that are all 20A circuits. According to 334.80, the 90°C column can be used for derating purposes of NM cable, so that's 30A for #12's. Since we have 8 current carrying conductors they would be derated by 70%. 70% of 30A is 21A, so we're still good.

Correct me if I'm wrong here (happens occasionally).

To answer the original question, you may staple two 14-2, two 12-2, and two 10-2 under one staple. However you may only staple one of each of the following 14-3, 12-3, and one 10-3 romex under one staple. And just for reference you need to staple within 6" of an outlet, and every three feet after that. When a wire passes through a hole that is counted as a means of support, and you do not need a staple for 3' after the hole.

Thommy,

I don't know if you noticed, but this is an old thread.

To add, your information is not 100% correct.

Quote:

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Originally Posted by Washington1

To add, your information is not 100% correct.

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Not even close!