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Posted By: George Little Physical protection - 08/15/05 11:26 PM
We have an inspector in our area who wrote a violation quoting 334.15(B). The installation involved installing NM cable horizontally through the studs in an unfinished garage. The inspector wanted the wiring to go up and over instead of around the garage at about 3 feet above the floor. What is the opinion of this forum?

I told him to count his belssings because I didn't think plastic NM cable boxes were Listed for use in exposed wiring. Seems like this came up a few years ago at an IAEI code panel and a UL guy made a point of this.
Posted By: George Re: Physical protection - 08/15/05 11:55 PM
I would suggest protection is necessary.
Posted By: walrus Re: Physical protection - 08/16/05 12:13 AM
If he ran the NM up and over and then down would he need protection for the portion that came down??. The original description would pass in Maine without a doubt.
Posted By: luckyshadow Re: Physical protection - 08/16/05 12:28 AM
Go into my garage and you will see romex running through the wall studs at about 3' off the floor. Inspector had no problem with it. Is this a local "code" thing or is the inspector pushing his own ideas on you ?
Posted By: gfretwell Re: Physical protection - 08/16/05 01:30 AM
"Physical damage/protection" always seems to be a local decision.
"Subject to physical damage" is always a subjective question. [Linked Image]
Posted By: e57 Re: Physical protection - 08/16/05 01:31 AM
Around here NM and MC for that matter, is subject to damage <8'AFF. In fact we do alot of corrections on exactly that type of work. It's obvious of the hazard when you walk in to do the work, and find all kinds of things hanging on it. Like crowbars, boxes stuffed into the stud-bays, and once, a kayack tied to it. Even above 8', we pipe it unless it is planned to be rocked.

As far as Code goes, "protected from physical damage where necessary", is pretty subjective, and lends alot to the AHJ.

As for the boxes, as you mention,
Quote
314.17 (C) Nonmetallic Boxes and Conduit Bodies.
Nonmetallic boxes and conduit bodies shall be suitable for the lowest temperature-rated conductor entering the box. Where nonmetallic boxes and conduit bodies are used with open wiring or concealed knob-and-tube wiring, the conductors shall enter the box through individual holes. Where flexible tubing is used to enclose the conductors, the tubing shall extend from the last insulating support to not less than 6 mm (1/4 in.) inside the box and beyond any cable clamp. Where nonmetallic-sheathed cable or multiconductor Type UF cable is used, the sheath shall extend not less than 6 mm (1/4 in.) inside the box and beyond any cable clamp. In all instances, all permitted wiring methods shall be secured to the boxes.
Sounds like the boxes need clamps for NM....
Posted By: Alan Nadon Re: Physical protection - 08/16/05 04:53 PM
You forgot to read the exception that followed the rule. "...where the cable is fastened within 8 inches..."
An AHJ could argue that the box is not IN a wall but it would be a weak case.
Alan--Inspector
I would approve the installation.

Cheap, quick fix: nail scrap lumber, insulation board, particle board, etc. around the wall to cover the NM.
Posted By: Mvannevel Re: Physical protection - 08/23/05 12:57 PM
I'm not sure where your area is at George (I believe you're in Michigan too), but it's come up in mine as well. I personally have always allowed it and will continue to do so. 334 permits NM for exposed and concealed work. I doubt that where run through bored holes around the perimiter of a garage, it's any more subject to physical damage than it is where it's run through bored holes in floor joists in a basement. How many times have you seen the lady of the house use those cables to store clothes from on hangers? In fact, if you think about it, it's probably more likely to be damaged where it's stapled down the side of a stud. As stated earlier, "subject to physical damage" is a rather subjective phrase.
Posted By: SolarPowered Re: Physical protection - 08/23/05 04:21 PM
Quote
... and find all kinds of things hanging on it. Like crowbars, boxes stuffed into the stud-bays, and once, a kayack tied to it.

Quote
How many times have you seen the lady of the house use those cables to store clothes from on hangers?

I don't think I'd call that, "Subject to physical damage." I'd call it, "Failure of foolproofing, due to development of a better fool." [Linked Image]
Posted By: tom25 Re: Physical protection - 09/02/05 10:48 PM
What is the difference with NM cable installed in bored holes within the floor joist in an exposed basement ceiling.
Posted By: gfretwell Re: Physical protection - 09/03/05 04:55 AM
Tom, in a practical sense I see no difference. My sister's family used to hang the laundry from the romex in the ceiling.

on wire coat hangers
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