Do any inspectors in you jurisdictions permit an exception to 334.15(C) for the first 12" off a foundation wall, or off the middle support beam in a basement. In other words, can you staple smaller sized NM cables to the bottom of joists within 12" of the walls, or beams?
Redsy- We're not on the '05 code here in Michigan but I follow you with the 12" example. I guess I'd have a problem with it and ask the installer to comply with the literal wording of the code. In that same code section they make reference to having a non-metallic bushing or adapter on the end of the conduit or tubing where the NM cable enters. Does this mean we can't use a metal fitting in this application? This is new in the '05. Another new item in Article 334 is the reference to using thermal insulation for fire or draft stopping & derating conductor ampacity when running 2 or more cables through a framing member- 334.80.
I guess the fun will begin soon
[This message has been edited by George Little (edited 01-30-2006).]
Re: Let me have 12"#97187 01/31/0610:29 AM01/31/0610:29 AM
Derating really won't be an issue until it is around 4 RX in a hole since 240.4(D) and the 90c insulation creates a lot of wiggle room. The only tricky spot may be right above the panel. (but that has always been ugly). Interesting question ... what if I "nipple" through the insulated hole? A nipple <24" does not get derated. Short little pieces of conduit may be saved from the dumpster by this.
Re: Let me have 12"#97189 01/31/0608:07 PM01/31/0608:07 PM
OK, no staples. What about "Stack-Its" installed on the beam at the proper spacing 4'6"(or less),and several or more NM Cables supported by them? This is common in my neck of the woods, as is the 12" rule.
Re: Let me have 12"#97190 01/31/0609:03 PM01/31/0609:03 PM
Redsy- I can support your Steelers but not your 12" rule. Small cables below the floor joist in the basement need protection via running boards or some other method but the 12" rule don't get it in Michigan
Re: Let me have 12"#97191 01/31/0610:36 PM01/31/0610:36 PM