Securing NM when holes are present

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kacrawford

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1. Are staples required when NM is running through holes in the studs or is the cable considered fastened? As long as the holes are spaced less than the minimum fastening distance is this an acceptable means of securing the NM even if there are some vertical sections in the runs per 334.30?

2. when the NM is secured via the clamp in the junction box is a staple still required within 12"?

334.30 states that unless the run is vertical. But this isn't very clear.


Thanks!!
 
Re: Securing NM when holes are present

From the '99 NEC(I don't know version you're on or if newer versions have rewritten this).

"Cable shall be secured in place at intervals not exceeding 4? ft.(1.37 m) and within 12 in.(305 mm) from every cabinet, box or fitting."

"Cables run through holes in wood or metal joists, rafters or studs shall be considered to be supported and secured."

If the NM wasn't fished into a concealed location and the bored hole is within 12" of the box, the hole "supports and secures" the cable.
 
Re: Securing NM when holes are present

The '02 and '05 are substantially the same. :)

1. Yes, see 334.30(A).

2. Yes. But if there is no clamp present in a single gang box, the NM shall be secured within 8" of the box, per 314.17(C), exception.

"Other than vertical runs" would tend to be horizontal, wouldn't they? :D
 
Re: Securing NM when holes are present

kacrawford

You have made reference to 334 and NM cable so I assume you are in 2002 or 2005 cycle.

1. Are staples required when NM is running through holes in the studs or is the cable considered fastened? As long as the holes are spaced less than the minimum fastening distance is this an acceptable means of securing the NM even if there are some vertical sections in the runs per 334.30?
Click to expand...
334.30 (A) Horizontal Runs Through Holes and Notches. In other than vertical runs, cables installed in accordance with 300.4 shall be considered to be supported and secured where such support does not exceed 1.4-m (4?-ft) intervals

2. when the NM is secured via the clamp in the junction box is a staple still required within 12"?
Click to expand...
314.17 (C) In all instances, all permitted wiring methods shall be secured to the boxes.
334.30 (A) cable is securely fastened in place by an approved means within 300 mm (12 in.) of each box,
314.17 (C) exception single gang boxes not larger than a nominal size 57 mm ? 100 mm (2 ? in. ? 4 in.) mounted in walls or ceilings, and where the cable is fastened within 200 mm (8 in.) of the box


334.30 states that unless the run is vertical. But this isn't very clear.
Click to expand...
There is more than one place that needs to be looked at when securing a cable to a box. The type cable and the type box will call for different ways of securing. You ask about NM cable so here is the sections that relate to your question.
:)
 
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