How many nm cables under a staple, with code references

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knightm1

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I haven'y wired a house in several years as I am currently an Industrial electronic and electrical repair technician. I am wiring my own house,when I wired houses, when I was younger, we allowed to have a couple of cables under a staple. What are the current rules. I have looked at several old posts and in the hand book with no luck as some say none and others 2:mad: Any help?
 
334.40 is where we find the rules for securing and supporting romex.

There is no mention in the NEC as to how many cables under a staple.

However, many staples are listed to hold two cables or less, which would make securing three cables under those staples a 110.3(B) violation.

IMO, it is much ado over nothing to fail such an installation.

Do a search for zip-ties, Stak-its, etc., to see other's preferences for products to secure NM cable.
 
NM

NM

There isn't an art. specifying the number of nm's under a staple, you would use art 110.3 (B) installation and use. In other words manufacturers spec's.
 
knightm1 said:
I haven'y wired a house in several years as I am currently an Industrial electronic and electrical repair technician. I am wiring my own house,when I wired houses, when I was younger, we allowed to have a couple of cables under a staple. What are the current rules. I have looked at several old posts and in the hand book with no luck as some say none and others 2:mad: Any help?
Click to expand...

We use a brand called Stacker Staples that indicate on the box the number and size of cables under each staple.
 
334.30 Securing and Supporting
Nonmetallic-sheathed cable shall be supported and secured by staples, cable ties, straps,
hangers, or similar fittings designed and installed so as not to damage the cable, at
intervals not exceeding 1.4 m (4 1/ 2 ft) and within 300 mm (12 in. or 8" using 314.17(C) Ex. if meets allowance) of every outlet box,
junction box, cabinet, or fitting. Flat cables shall not be stapled on edge.
Sections of cable protected from physical damage by raceway shall not be required to be
secured within the raceway.

Most staples allow (2) romex cables ( NM Cable ) but not on edge as stated in 334.30
 
knightm1 said:
I haven'y wired a house in several years as I am currently an Industrial electronic and electrical repair technician. I am wiring my own house,when I wired houses, when I was younger, we allowed to have a couple of cables under a staple. What are the current rules. I have looked at several old posts and in the hand book with no luck as some say none and others 2:mad: Any help?
Click to expand...

Welcome to the forum knightm1

Another issue to think about is having several cables under staples for a distance of more than 24 inches.

Where the cables enter the top of a panel it is easy to have them bundled under staples for more than 24 inches.

With four two wire and one three wire cables under staples for more than 24 inches the ampacity of the conductor is now half its rated value outlined in Table 310.16.
The same is true where fire caulking is used at the top plate.

See section 334.80 and Table 310.15(B)(2)(a).
 
going through the plate into the panel it is easy to add a block and fan out the cables.This is a typical "West coast" install. Meter and distribution on the outside.

PDRM0024.jpg
 
How many nm cables under a staple,with code references

How many nm cables under a staple,with code references

radiopet said:
334.30 Securing and Supporting
Nonmetallic-sheathed cable shall be supported and secured by staples, cable ties, straps,
hangers, or similar fittings designed and installed so as not to damage the cable, at
intervals not exceeding 1.4 m (4 1/ 2 ft) and within 300 mm (12 in. or 8" using 314.17(C) Ex. if meets allowance) of every outlet box,
junction box, cabinet, or fitting. Flat cables shall not be stapled on edge.
Sections of cable protected from physical damage by raceway shall not be required to be
secured within the raceway.

Most staples allow (2) romex cables ( NM Cable ) but not on edge as stated in 334.30
Click to expand...

Remember 2wire cable must be stapled on the flat side, so IMO 3and 4 wire nm cable does not have flat side so it can not be doubled under a staple wit a 2 wire. I know I will get clobered with this one.
 
welcome from another tar heel.. 2 wires is standard however, most inspectors don't want to see a 3 wire cable with others, ie, its okay with 2-14/2 or 2 -12/2. Try these for those situations.
6797674.jpg


I have also laid a 2x4 on edge evry three feet coming down a wall and staple to that, esp. at the panel.
 
Dennis Alwon said:
I believe if you use tie wraps then your bundling and have to derate.
Click to expand...
not if it's one cable, or two...for that matter ten, as long as I stick to the 24" rule. See 310.15(B)(2)(a)
:smile:
 
acrwc10 - I'd also like to see how those NMB's leave that panel. It looks like a bunch of them seem to come together in very close proximity. Is it some type of multiple style connector? I'm only aware of the NMB connector that allows two to come in to a single 1/2" KO.

Thanks

Brett
 
acrwc10 said:
going through the plate into the panel it is easy to add a block and fan out the cables.This is a typical "West coast" install. Meter and distribution on the outside.

PDRM0024.jpg
Click to expand...

Very pretty! My kind of work.
 
donselectric said:
why are the breakers outside ?
Click to expand...

Two reasons 1) The Builder is "CHEAP" 2) This is california.The weather here is never bad:D

The NM going into the panel is in multiple 2 screw connectors, it is hard to see in the picture but they are more then one row, and more then 1 NM per connector.

[edit to add] Not every connector has more then 1 NM just some.
 
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acrwc10, Your work is much better than this mess. This was taken when I visited So Cal for the fist time back in 1998. I'm guessing not much has changed in the world of tract homes?

electrical2.jpg
 
georgestolz said:
Dennis, would you like to borrow my Jump To Conclusions Mat?
Click to expand...
Okay George, I'm sorry I should have said it could possible be bundling. I wasn't specific enough-- shoot me.
 
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