Conductor length


Old 04-07-12, 08:22 AM
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Conductor length

Sorry for the barrage of questions on this, but I recently realized that something I've been pretty much just eyeballing (length of conductors in box) may have a code requirement so I have a bunch of related questions. Is there a code for how long a conductor has to extend either past the box or from the point that it emerges from the sheathing in the box? Assuming there is one, what should I do on new conductors where I may not have left enough wire? Should I pigtail them to extend the certain distance or just leave them as is unless extremely short? My concern with pigtailing is that, while meeting calculated box fill requirements, the box might end up stuffed. Also, would you measure from the point of the pigtail or from the point the original wire emerges from the sheath to end of new pigtailed wire?

Also, just in general, is there any immediate safety rationale for this code or is it more something to make future connections/modifications easier so you have sufficient wire to safely work with? I ask because I have a significant number of new or modified junction boxes and receptacles that I have installed and have already been inspected. Very few of them were physically inspected by the inspector, but they were all done under the inspection. Is this important enough that I should go back on all connections and recheck? My thinking is no, but that is based on my assumption that this is more for future convenience than immediate electrical safety issues.
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Old 04-07-12, 08:46 AM
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Generally leaving 1/4" or so of sheathing inside the box after the strain relief is accepted, and an 8" length of wires beyond that. However, if it ain't broke, especially in junction boxes, don't go back and "fix" it unless you have safety concerns. Are the conductors capped tightly laid in the box without "cramming" and is the jb covered securely/
It makes it easy to install fixtures to have that much hanging out rather than cramping things up at the box. If the conductors are cut too short, but are accessible, then a pigtail would be in order. Remember, we can't see the work you did.
Old 04-07-12, 03:45 PM
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wire Length

What Larry said. Also, if you have deep boxes, the wire should extend 6 in. outside the box.

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