Conduit and NM or UF Electricle Wire

[jamey07]

Could some clarify or provide me on information regarding the use of conduit and NM or UF electrical wire. Here are my questions:

Can NM or UF electrical wire be run through conduit?

Should NM electrical wire be run through conduit in an exposed basement?

Any information would be helpful and appreciated.

Thanks

 

[electricman2]

Re: Conduit and NM or UF Electricle Wire

Either type can (and should) be run in conduit when needed for protection from physical damage.
334.15(B)

 

[jamey07]

Re: Conduit and NM or UF Electricle Wire

A follow up to my previous questions. Is it a violation of NEC to have UF wire, that is above ground, attached directly to an exterior masonry wall?

Thanks again!

 

[electricman2]

Re: Conduit and NM or UF Electricle Wire

I believe 340.12(10) and/or possibly (9)would prohibit this. If you need to install it on an exterior masonry wall, just enclose it in RMC,RNC,EMT,etc.

 

[ryan_618]

Re: Conduit and NM or UF Electricle Wire

I think your local AHJ is the only one that can answer your question. Electricman2's replies are valid, but it all hinges on what the AHJ considers "subject to physical damage".

 

[electricmanscott]

Re: Conduit and NM or UF Electricle Wire

Is it a violation of NEC to have UF wire, that is above ground, attached directly to an exterior masonry wall?

No it is not depending on the location. 10 feet above the ground running along the side of a house is probably ok. Lower than that amy not fly as due to damage possiblities as already mentioned.

 

[Guest]

Re: Conduit and NM or UF Electricle Wire

Originally posted by ryan_618:
<snip> it all hinges on what the AHJ considers "subject to physical damage".

As an inspector what are your physical damage guidelines when you inspect supersurface UF or NM? Thanks!

When do you tag it, and what solutions do you propose when you tag it? Thanks!

 

[ryan_618]

Re: Conduit and NM or UF Electricle Wire

Wayne: Good question. I hate to say it, but it almost has to be a case by case basis. I don't like to see it on the wall if it's less than about 6 or 7 feet above the floor. I will write on my report that it be protected, and the installer will usually realize that that means EMT or equivalant.

I agree with what the others have written, I simply added my thoughts because there is no right or wrong answer to this...only opinions, and only one opinion really matters--the AHJ of the installation.

 

[iwire]

Re: Conduit and NM or UF Electricle Wire

The only way IMO is case by case, exposed in one location can be perfectly safe while in another may be asking for trouble.

I do think it is worth looking at the NEC to get a feel for what is allowed.

334.15 Exposed Work.
In exposed work, except as provided in 300.11(A), the cable shall be installed as specified in 334.15(A) through (C).

(A) To Follow Surface. The cable shall closely follow the surface of the building finish or of running boards.

(B) Protection from Physical Damage. The cable shall be protected from physical damage where necessary by conduit, electrical metallic tubing, Schedule 80 PVC rigid nonmetallic conduit, pipe, guard strips, listed surface metal or nonmetallic raceway, or other means. Where passing through a floor, the cable shall be enclosed in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC rigid nonmetallic conduit, listed surface metal or nonmetallic raceway, or other metal pipe extending at least 150 mm (6 in.) above the floor.

I made the part I find interesting bold.

To me that suggests that the NEC does not necessarily believe that NM on a wall as low as 6" needs protection.

Again it is up to the AHJ as in some locations this could be subject to damage but not all locations.

 

[drg]

Re: Conduit and NM or UF Electricle Wire

In response to,

Can NM or UF electrical wire be run through conduit?

Should NM electrical wire be run through conduit in an exposed basement?

Any information would be helpful and appreciated.

First question ( yes)
Second question,(yes) we usually run 1/2" or 3/4" EMT from the outlet box stubbed up to the sill area in homes when using NM cable, this applys to the switch boxes if exposed work also.

John

 

[iwire]

Re: Conduit and NM or UF Electricle Wire

Originally posted by drg:
Second question,(yes) we usually run 1/2" or 3/4" EMT from the outlet box stubbed up to the sill area in homes when using NM cable, this applys to the switch boxes if exposed work also.

John that is more like what you like to do than what is required.

If the panel is located on the basement wall do you sleeve all the NM with pipe entering the panel?

Article 334.15(A) clearly allows the use of NM exposed fastened to the building surface.

There is no general requirement to cover all exposed NM in a basement or any location.

 

[pierre]

Re: Conduit and NM or UF Electricle Wire

This part of the code definitely leaves a lot of room for the AHJ. His/her decision is really going to be based on personal experience, such as Ryan saying that below 6 of 7 feet he wants protection. I have no problem with that type of decision as long as it is consistant and well known ahead of time. But I do wonder Ryan how you have come to that decision.
I emailed the NFPA about 'short lengths' for physical protection and the response back was interesting. They say that it does not hinge on 'relative' short lengths, such as a space 300 feet long and you use only say 30 feet of conduit for protection. A short piece in the response was "less than a length' of the conduit. I tend to agree with that. If you were to need more than a length of conduit, IMO you should pipe the entire run.

Pierre

 

[ryan_618]

Re: Conduit and NM or UF Electricle Wire

Pierre,
Very good question. I am a big beleiver in enforcing the minimum code. I find it both interesting and dissapointing that the NFPA would even use the word should. I can't tell an installer that they should do something, that is not my job. If it meets the code than I pass it, if it doesn't I red-tag it.

I don't really know how to answer your question...as I stated before, it is sort of a case by case basis. Sorry if I seem to be dancing around the issue here, but I really don't know how to answer your question

 

[drg]

Re: Conduit and NM or UF Electricle Wire

Bob, I never questioned or looked up a article for this until now,

334.15 (b) is probaly more in line with our shop way of thinking, they simply protect any NM on a wall area of a basement to prevent physical damage and put no more thought into the issue.

To answer your question about sleeving all NM cable coming into a panel ,

one crew leader uses 2" pvc stubs out the top of the panel, and the other guys use NM connectors without any sleeve , I just do what ever the guy in charge does as it is only just me and 1 journeyman on a residential job.

We have crew members that have never really run NM cable and it was funny when they were trying to use a NM cable cutter, they are on big federal or state jobs 99 % of the time and hate residential.
I have to do all so I can learn, but enjoy the big federal / state projects a lot more also.

John

 

[iwire]

Re: Conduit and NM or UF Electricle Wire

John we are on the same page.

I will protect NM when I think it is a good move.

My only point is that the NEC in many cases does not require it.

Going beyond the code minimums is great for the customer.

Ryan are you dancing? It must be tough making the call on "subject to physical damage" we all have different ideas on what that means in regards to NM.

Some members think all NM exposed is "subject to physical damage" and others would run it across the floor.

 

[Guest]

Re: Conduit and NM or UF Electricle Wire

It would be an easier call if we worked under one AHJ and one electrical inspector for our whole career. Even in one AHJ, if it's large you cannot assume you will always get the same inspector, especially on sick days, days off, or vacation days. City vs. county vs. state or federal makes a difference too. Multiple cities, multiple counties, it becomes luck of the draw.

When an inspector puts something on his/her punchlist we have to take it seriously. We have to assume they have some teeth in their citation. If it makes sense or it's easy we just cave in. Other times we look to the NEC and see if the inspector is right. If we find no flaw, we file away this call as fact.

When inspectors are NEC wrong and remain unchallenged it can have a lasting effect on the way we do our work from that point on.

Sometimes when an inspector is wrong it makes so much sense that even if we know they're wrong we will implement the improved practice as part of our ongoing style. Years later it might actually appear in the NEC!

A bad or good call by an inspector can have a lasting effect. It's a big job. It's a big book. It's a moving target. It's subject to interpretation.