ECN Forum Forums General Topics of the Trade General Discussion Area Most Common Problems and Violations Seen

WayneSargent;
the NM deal has little electrical rationale. Something about products of combustion was mentioned, other than that, it's a manufacturer's war......

Sparky, do you know the IAEI Joe from Boston, last name escapes me now, ends every other sentence with "eh?" and has something to do with printing of the Analysis, I believe. He addressed our inspectors recently at a meeting and when we asked him about this change, it sounded like something was rotten in Denmark. It sounds political, and I wish I had time to study the ROP's and listen in on the code panel discussions. But precedents are set with fiascos like this, and I hope it isn't the way it sounds, with manufacturers' attorneys dicating the verbage for code changes to fit their products. It wouldn't be a first. I for one will be writing a proposal with photos from my inspections to put the romex back where it belongs... before this November for the 2005. I'm guessing there will be a few hundred others doing the same on this one change.

Wayne,
Actually they NM people may have lost more than they gained. See 334.12(A)(1). It is no longer permitted in buildings other than dwelling units above drop ceilings. This eliminates its use in many commercial properties where it was permitted in the '99 code.
As far as the three story limit, there is no evidence that NM magically becomes more hazardous when you install it more than 3 floors above grade. It has been permitted by at least one state for this type of use for the last 2 or 3 code cycles. There has been no problems caused by its use.

Best of luck to them. Maybe knob and tube will make a comeback? As far as NM becoming more hazardous above a certain number of stories, "magically," here's my smart a** retort in kind. Its not about stories, its about construction durability and longevity. They set precedents and convolute codes with this kind of change. If we are going to allow NM, allow it. Don't drag another NFPA document into the mess and ask me to spend more time in plan reviews that I don't get enough time to review to begin with. They couldn't use UBC construction types, had to have their own. It never ends. And then they hope to entice other countries to follow our lead and buy our convoluted abortion. The original question here was about "problems" and "hazards" we see. Its all a matter of degree I suppose. My thinking is that allowing any extended useage of NM in commercial and industrial applications will result in increased problems and hazards, which I'm in the business of avoiding. Rope it! I'll pipe it, then we can compare stories in 50 years.

Subpanels with interconnected neutrals and grounds are my beef. Also shared neutrals not on a tandem breaker!

Wayne,
How is the durability and longevity of the product affected by how high above the ground that it is installed? By the way, I have never been paid to install NM cable as a permanent part of a building. I use conduit and wire, but I don't see any increase in hazard when the NM is installed at a higher elevation. No one could prove that there is any increase in hazard and that is why the NFPA Standards Council was forced to permit it in these building under the threat of major a lawsuit. The code cannot be used to support certain products or require the use of additional labor units unless there is proof that these installation methods are required for "the practical safeguarding of persons and property from hazards arising from the use of electricity".
As far as knob and tube, if you exclude the fact that it doesn't have an EGC it is among the safest wiring methods ever used in a building when it has not been modified by DIYers.
Don(resqcapt19)

Don, 334.12 prohibits "open runs in dropped or suspended ceilings..". Does this mean that NM can't be used at all, or is it just for dropping down (open) to feed fixtures?

Elzappr
It is my opinion that if you can see it by removing a ceiling panel then it would be a violation in any occupancy except dwelling units.