ECN Forum Forums Photo Discussion Forums Photos for General Discussion Romex and the Strip Mall Fire

PC, that is a rather interesting request- and I suspect that you know the answer better than most!

Prior to the 2005 code, the NEC, in sections 334.10 and 334.12, very nicely danced around the issue. What it seemed to say - while not explicitly saying so- was that NM was intended for use in rather small, basic dwellings. Reading between the lines, the code seemed to assume that NM was designed for use in wood-stud (balloon frame) construction- a type that is rather rare in commercial applications, and limited to three floors by the strength of the wood.

There seemed to always be the presumption- I remember many such discussions in the '60's, in a "booming" Chicago area housing market- that the reason for NM was to allow lesser skilled folks to rapidly run the minimal circuits needed in homes.

Now, "I recall" and "It seemed" are hardly the basis for a code ruling! Even with the liberalizing of "uses permitted" in the 2005 NEC, many places still very much restrict the use of NM. Some ban it completely; others specifically restrict it to homes. For example, the City of Reno ammends 334.10 to limit the use of NM only to residential occupancies (new construction).

Perhaps it is a trade "snob factor" that leads many electricians to associate NM with DIY work; yet these pics show a case of where someone managed to mess up something as simple as NM! The lack of bushing and support make it clear that whoever did this work had not the slightest training in proper wiring methods.

thank's for pointing that out. it's not so much a romex bx/mc issue as it is clearly that someone came in and threw this work in with no regard for the code or anyone's life.
to see the rest of the work in person you would clearly see that this person has no buisness doing elec work.

Reno, that is the way it is where I'm at, no NM in commercial apps.

Usually we find it done by the out-of-staters, who never bother to check local codes and ordinances. The come in and out under the cover of darkness, never pull permits, or inspections.


Dnk..

a quick look in the 2002 code (we haven't adopted the 2005 here yet) shows a change in the use of NM in dropped ceilings. No longer legal in anything other than single/multifamily dwellings.

As a rule, MC is wire of choice for commercial (quicker and easier than taking all the extra steps needed for romex in steel studs) but, it was legal at one time.

As a quick aside, we have a mess of buildings on the beach here that are all in romex - the thing is, all these buildings are 8,10,12 story buildings. But they are right on the beach and the installations have lasted for over 20 yrs now. MC/BX would have completely corroded years ago.

Can't use romex in commercial 'round here either... In mixed use buildings we can use it in the residential portion seperated by a 2-hour wall and ceiling envelope.

Local code:

From what I understand, and it is eveident in the construction of many buildings here, that early on romex in its early incarnations wasn't allowed in residential either. Apparently held out until the mid-late sixties. The story Ol' Uncle Joe told me was that some Mayors daughter died in what was deemed an "electrical fire", and that new fangled "romex" was blamed. So you'll see homes wired in K&T up until then.

Other than that, pic #1 obviously had other issues with OCP, on top of the insulation failure.

Not at all.

MC and BX/AC cable have been used successfully here inside buildings all up and down the coast.

The NEC 3 story NM rule has been in effect for at least 30 yrs. Looks like $ talked in this case?

seems to me, if Mc corroded away, so would the boxes, receps, meter cans,breakers...ect..

Dnk...

not to the same extent. different coatings. right on the beach you'll find mc/bx that is nothing but rusted shards, but the boxes still are instact to great extent.

can't explain it - not an engineer- just have seen it often.

Oh, the other stuff corrodes, too. This cover was under a carport for 40 yrs.



The old guy that brought this into the supply house was very mad that they didn't have a new exact replacement cover. He was yelling that everything else was just fine, and he didn't want a whole panel.

LOL @ electure...