NM above suspended ceilings

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peter d

peter d

Senior Member
Location
New England
Does anyone else besides me think this restriction is ridiculous? How many thousands of building were wired this way without any problems? And suddenly the code changes. :cool:

Anyway, I had to rant a little because I'm a little peeved because I had to spend the last few day ripping out NM cable in a commercial occupancy (that was being renovated) for no other reason than the code had changed. :roll:
 
Re: NM above suspended ceilings

Peter
Were you ripping out the existing or new NM cable?

I do not see where it says you have to rip out the existing NM cable - you are not permitted to install NM cable in new installations. There are different requirements for different types of occupancies.

[ April 24, 2005, 08:19 AM: Message edited by: pierre ]
 
Re: NM above suspended ceilings

I think it should be outlawed period. It is nothing other than glorified extension cord with solid conductors. Get ready to throw rocks... IMO I feel it is a crappy wiring method and often abused and misused, not to say other material can't be or isn't at times. I am NOT saying Peter you are doing crappy work! I want that fully understood and please do not take it that way. I have run it as much or more than you have and am just saying the method itself is crappy. I also think MC cable is junk. The sheath is not listed for a fault return path and it should be. IMO the minimum should be BX or other method to carry a fault. I also believe non metallic raceways should be limited. Man, I am gonna keep on and we are going to be back in the RIGID days! But you see my point. All materials have the potintial to be misused. Some just more than others, and inspectors can only catch SOME of the PERMITTED jobs. Ya'll know how that goes. Thank god for home stores!
 
Re: NM above suspended ceilings

It's been a few years since i did this but back when we were on 99 code my boss had me wire a remodeled office with suspended ceilings in romex.The inspector was not a bit happy but was forced to pass it on rough.On final he told me he thought he was gonna have me for supporting of romex,but he did his home work and seen the exception for whips.He did point out to me that when we adopt 02 it would fail.Is it safe ? Actually i would say yes.It is in no more danger than romex getting stamped on in attics and cutting into staples.Quality,NO.But then very few of our jobs are in pipe anymore.Customers want price first quality second.
 
Re: NM above suspended ceilings

Originally posted by necbuff:
I think it should be outlawed period. It is nothing other than glorified extension cord with solid conductors.
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Kenny other than your personal opinion do you have any evidence that when installed correctly NM does not perform as safely as RMC?

As you said any wiring method can be misused, the NEC IMO does not take that in to account. The NEC assumes any wiring method used will be installed and used correctly.

If I am having a home built I see no reason that I should have to pay for RMC or EMT when NM has a long history of adequate service.

Should some agency also outlaw small cars that are not as safe as some large cars?

IMO the choices should remain with the person paying the bill. :)
 
Re: NM above suspended ceilings

Originally posted by necbuff:
I think it should be outlawed period. It is nothing other than glorified extension cord with solid conductors. Get ready to throw rocks... IMO I feel it is a crappy wiring method and often abused and misused, not to say other material can't be or isn't at times. I am NOT saying Peter you are doing crappy work! I want that fully understood and please do not take it that way. I have run it as much or more than you have and am just saying the method itself is crappy. I also think MC cable is junk. The sheath is not listed for a fault return path and it should be. IMO the minimum should be BX or other method to carry a fault. I also believe non metallic raceways should be limited. Man, I am gonna keep on and we are going to be back in the RIGID days! But you see my point. All materials have the potintial to be misused. Some just more than others, and inspectors can only catch SOME of the PERMITTED jobs. Ya'll know how that goes. Thank god for home stores!
Click to expand...
While we're at it let's just get rid of electricity all together. :D
:roll:
 
Re: NM above suspended ceilings

Kenny, you should be ducking the rocks well by now.

Nothing is wrong with NM cable where it is installed in accordance with the rules of the NEC . . . period. It is in fact a great wiring method that is adequate for the purpose. The problem with NM is the ability to abuse it. The problem with an automobile with a large engine and light body is the ability to abuse it.

I do agree that some of the wiring methods are better than others, that is why there are different uses for different wiring methods in different occupancies. :D
 
Re: NM above suspended ceilings

I knew when I wrote it they would start flying! There was probably a few chairs, fish tapes and several pairs of kliens in there as well. I love you guys just the same. As I said it was an opinion as we all have in here and I would never want to offend anyone in here. This site, I think, is for us to learn and express opinions. I am just not a Romex lover. It along with RNC are possibly the two most abused wiring methods there are. People hang clothes on Romex and if the EGC is opened, the bonding protection is gone. Bob, Have you ever seen an NM cable blow out the side? I have seen cases where the cable blew out, opened the EGC and welded the ungrounded conductor to the EGC. Now with the EGC open it could not return to the source, thereby energizing the EGC and everything bonded to it. With BX it would have likely cleared because of an effective ground fault return path. At least you may still have adequate protection with BX or a metallic raceway. RNC is often installed where subject to damage emerging from the ground and you have the same bonding problem. Not to mention it looks terrible and while maybe sunlight resistant it turns colors, and not matter how many straps you install it will droop if ran horizontal. IMO RNC is fine underground and for sleeving and maybe a vertical riser. Maybe there are some uses for the above. Just not as many as permitted. So, Please yell before posting so I can get behind my desk..... Oh, and the world is flat ;) .

[ April 24, 2005, 08:52 PM: Message edited by: necbuff ]
 
Re: NM above suspended ceilings

Similar to people who don't like guns, it is not the wiring method to be blamed, but most likely the installer of the wiring method. As long as any of the wiring methods are installed with the environment, use and other important criteria accounted for, there is no problem.

Did you ever see a gun shoot someone when not in a persons hand?
Same goes for cable installations. ;)
 
Re: NM above suspended ceilings

Originally posted by pierre:

Did you ever see a gun shoot someone when not in a persons hand?
Same goes for cable installations. ;)
Click to expand...
So, NM-B is considered a weapon. Officer I swear, I did not know the NM connector was loaded.

Seriously (even though I know it wasn't that funny); I think the quality of NM manufacturing has gone down. It used to be pretty tough stuff. The old stuff paper impregnated, then paper around each conductor.
Later (such as Anaconda) the sheath was plastic and TOUGH.
Now the sheath comes off with hardly any effort. It is more suseptible to damage when installed.

Just a comment that I see it as ironic the quality goes down and restrictions ease up.

Historical note: (many probably know) Serious attempts have been made to prohibit or outlaw NM in the past. I don't any details, I just remember the reports. Vintage 1960'sor 70's
 
Re: NM above suspended ceilings

Larry I agree nm from days gone by was tougher to strip damage etc.,some of the stuff on the market today pressure shorts by lookin at it to hard.But it is allowed and cheaper than rmc or emt,production production.
Sounds like an old wrestling team from the 70`s the mongol`s condition condition as they hit each other`s chest.Ok showing my age with that one :D
 
Re: NM above suspended ceilings

I have read all of the comments about NM above suspended ceilings, and I must add my comment.
I worked in a large Chemical Plant for many years, and naturally you have offices and laboratories, where they have suspended ceilings.
I must point out, that nothing irritated more than to see the rats nest of NM wiring above a suspended ceiling.
The so-called electricians would just run the NM from point A to point B without any regard to workmanship, because it was out of sight.
So, with that being said, I for one am glad that they have stopped NM above a suspended ceiling.
 
Re: NM above suspended ceilings

So now the rats nest will be made out of MC.Sloppy workers will still do this.How much of this was inspected ? I have even seen EMT ran being held by grid wire and AC ducts.The slop wasnt the fault of the romex.

[ April 26, 2005, 05:43 AM: Message edited by: jimwalker ]
 
Re: NM above suspended ceilings

Originally posted by friebel:
I must point out, that nothing irritated more than to see the rats nest of NM wiring above a suspended ceiling.
The so-called electricians would just run the NM from point A to point B without any regard to workmanship, because it was out of sight.
So, with that being said, I for one am glad that they have stopped NM above a suspended ceiling.
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I do not believe it is the NECs purpose to protect you from being irritated by poor workmanship. :)
 
Re: NM above suspended ceilings

I have pulled many miles of romex and how neat it was depended on who i was working for.Had a few that wanted it ran with no twists and everything squared off.Others told me to just go from point A to B.You get what you payed for.If you want it neat then lets run pipe.Lets see pipe verses romex,maybe 5 times the price :roll:
 
Re: NM above suspended ceilings

Extension cord is safe too if used properly but I don't want it in my walls or for permanent wiring. Again I raise the issue of clearing a fault which no reply has been given. As for the rats nest, I know well the scenario mentioned but that could be done with any method, i.e. EMT bent with a truck tire. IMO, I think the minimum should be a metallic sheathed cable with a listed effective ground fault return path. With safety the issue, the cost is minimal and the cost would have to be past on. If everyone is so safety conscious as they claim to be, this should not even be questionable. Opened or energized ECG's would be drastically minimized.
 
Re: NM above suspended ceilings

Some places have banned the use of types AC and MC in houses because the emphasis on speed in residential construction led to quite a few fires when these cable types were used. We also lived in a house in New Jersey that was wired entirely with type AC cable. The branch circuits started blowing out because there were ZERO antishort bushings. I have also seen instances where an alledged electrician was brute forcing a dull hacksaw blade leading to a burr that would cut the antishort bushing.

I have run quite a bit of type NM in wood frame buildings, both residential and commercial. I do not see anything wrong just as long as I put off installation until after the alledged carpenters install the exterior sheathing and siding. I have seen some instances where the alledged carpenters were using overly long nails because that was what the nail gun uses. In the hands of a pro nail guns save on carpal tunnel syndrome but they also allow morons to drive nails. Swinging a hammer correctly is actually a very difficult to acquire skill. For me the problem was not mechanical aptitude but developing enough arm and wrist strength to control the hammer. Smacked my fingers quite a few times during the summers back in elementary school.

By the way, back in the 1980s there was a plenum version of type NM that was used in Ohio, Pennsylvania, and Massachusetts. Back then the 3 states had a state rule that allowed type NM in 4 story and taller buildings if the circuit was confined to a single floor. Very frequently the building had a fire sprinkler system. The reasoning was that by making branch circuits cheaper there would be more branch circuits leading to less heating of the wires resulting in lower net fire hazard.

However, aluminum sheath type MC cable such as corruclad lowered the cost of installing type MC cable. As long as you use silicon carbide abrasive paper and anitoxidant on the cable sheath and there is an internal copper equipment ground it works very well.
 
Re: NM above suspended ceilings

Any Municipality, Jurisdiction or governing body that restricts a permitted type wiring method because of poor wiring habits by the installers is in their own right IGNORANT.
If there is a consistent poor installation crisis that makes these authorities think a method should be banned, how about mandatory education...HMMM!!!! A revolutionary idea.

In my daily inspections, I see NM cable poorly installed, AC cable poorly installed, Conduit installed- must be by blind people.
We cannot and should stop blaming the wiring method and start resolving the real issue...MONEY!!!

Money makes the world go round, or stops it ;)

Lack of mandatory training is the number one issue that has been slowly destroying this industry for years/decades. In order to make a comeback from this issue, it will cost a lot of money and that is probably the biggest obstacle keeping education on the back burner now.
 
Re: NM above suspended ceilings

Originally posted by pierre:
Peter
Were you ripping out the existing or new NM cable?

I do not see where it says you have to rip out the existing NM cable - you are not permitted to install NM cable in new installations. There are different requirements for different types of occupancies.
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Sorry for the late response.
It was exsisting cable that we were removing. We were renovating a store, and we replaced all the old T12 drop in fixtures with T8's and added a few new circuits.

I agree with your statement. But again, it comes back to inspectors who don't understand the code and believe that if renovation work occurs, than the whole thing has to be brough up to modern codes. :mad:

I wasn't in charge. If I was, the cable would have stayed right where it was.
 
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