Nec 2005 334.15

[lmchenry]

In the NEC handbook Section 334.15c has an exhibit that seems to me to be a violation. Can the nm cable run parallel to the floor joist and stapled to the bottom (right side of picture)?

 

[celtic]

C) In Unfinished Basements.
Where the cable is run at angles with joists in unfinished basements, it shall be permissible to secure cables not smaller than two 6 AWG or three 8 AWG conductors directly to the lower edges of the joists. Smaller cables shall be run either through bored holes in joists or on running boards.

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As illustrated in Exhibit 334.1, nonmetallic-sheathed cables installed in an unfinished basement can be run through joists and attached to the side or face of joists or beams and running boards. Section 300.4(D) requires cables that are run parallel to framing members be installed at least 11/4 in. from the nearest edge of studs, joists, or rafters.

Are the NM's on a beam or joist?

Give 334.15(A) an eyeballing.

 

[lmchenry]

334.15

334.15

Sorry for the misdirection. My question refers to the cable on the bottom of the joist in the picture you submitted. Section 300.4d requires cables that are run parallel to be 1.25in from nearest edge.

 

[JohnJ0906]

Sorry for the misdirection. My question refers to the cable on the bottom of the joist in the picture you submitted. Section 300.4d requires cables that are run parallel to be 1.25in from nearest edge.

You forgot the rest of the sentence.

".... where nails or screws are likely to penetrate"

IMO, that shows a legal installation. Wouldn't do it myself, but not a 300.4(D) violation.

Might be subject to damage though.

 

[Dennis Alwon]

Sorry for the misdirection. My question refers to the cable on the bottom of the joist in the picture you submitted. Section 300.4d requires cables that are run parallel to be 1.25in from nearest edge.

I am not sure but I read this section , art. 334.16, to mean that cables smaller than 2- #6 or 3-#8's are allowed to be installed on the lower edge of the joist. The lower edge, IMO, is lower edge on the side of the joist, not the bottom. I believe one is allowed to run any cable to the bottom of the joist in an unfinished basement. This is no different than a running board. I may be wrong but that's my take.

I believe the reason to allow the larger cables to be run closer to the bottom edge is to allow the proper bending radius for the wire to turn up into the wall. If one were to decide to sheetrock the basement the cables on the bottom of the joist are obvious and would have to be moved. I guess the 1 1/4" up would have to be maintained for the smaller cables because they probably would never get moved up.

This being said I always keep my wires toward the middle and only use running boards around the perimeter. I also never staple to the bottom of the joist if I run parallel to the joist. Not even in crawl spaces.