Exposed NM cable in kitchen cabinets

[Umlaut]

I'm trying to sort out if NM is allowed to be exposed within a kitchen cabinet between the drywall (if the back of the cabinet is open) or the cabinet back or bottom and a surface-mount box mounted inside the cabinet.

Do you wire these using MC cable, or bare NM? Do you put the NM straight into the surface-mounted box, or through the cabinet first? (If you go straight into the box, how do you handle clamping requirements?) Some electricians I've worked with use a bit of flexible conduit between the box and the wall, or the box and the hole in the cabinet back or base.

I can't find anything in the NEC that makes me think that bare NM is not allowable. 334.12.A says that "exposed and concealed work in normally dry locations" is allowable; and any kitchen cabinet is such a location, isn't it?

Is the interior of a kitchen cabinet an exposed area that makes "protection from physical damage", per 334.15.A, a requirement?

Reading through 300.4, I don't see anything that pertains to non-enclosed areas, except for 300.4.C, which is about "spaces behind panels designed to allow access" -- which is exactly what a kitchen cabinet is, is it not?

There are days when I feel like I totally understand the code, and there days when I fell baffled.

 

[telectric]

I'm trying to sort out if NM is allowed to be exposed within a kitchen cabinet between the drywall (if the back of the cabinet is open) or the cabinet back or bottom and a surface-mount box mounted inside the cabinet.

If the back of the cabinet is open, then I would say No, It could be read that it violates the NEC's take on "protection from physical damage". The Inspector/AHJ may or may not pass this.

Of course, if its stapled in a vertical direction, where nothing can hang on it, I'm not sure. I wouldn't do this, I would install the wire in the wall, if this was not an option, the wire would be protected by flex of some sort.

 

[hurk27]

while "subject to be damaged" is a open statement that is misused many times, I feel exposed NM is not that dangerous, think of it this way, how many of us have simple lamp cords laying around in our house going to appliances just laying around on floors, counter tops, tables, and you think NM is dangerous?
I would say the NM would hold up much better then a cheap lamp cord, but we never think about this do we, so let me see how many of you are willing to outlaw lamp cords and have to hard wire everything in our home, didn't think so.

This has been brought up so many time at divisional IAEI meetings I have been to, and it was always answered that how much damage can NM really receive if it is in the back of a cabinet, you would have to really have to through something in there hard to damage it, maybe not a good idea to located in a knife drawer, but if common sense is used I don't see the problem.

I have been on job sites where a contractor had run NM across the road for power, and cars and trucks run it over all day and yes it fails after a couple days of this but just the fact it last a couple days of this torture is amazing.

 

[telectric]

while "subject to be damaged" is a open statement that is misused many times, I feel exposed NM is not that dangerous, think of it this way, how many of us have simple lamp cords laying around in our house going to appliances just laying around on floors, counter tops, tables, and you think NM is dangerous?
I would say the NM would hold up much better then a cheap lamp cord, but we never think about this do we, so let me see how many of you are willing to outlaw lamp cords and have to hard wire everything in our home, didn't think so.

I would agree, there is not much to a lamp cord, but a lamp cord is not meant to be a permanent installation, or any of the other appliance cords in a home. I do feel the same, NM is a tough jacketed wire, dangerous, I would have to say that any electricity in the home is dangerous. I defiantly would not want to hard wire everything in my home. haha.

This has been brought up so many time at divisional IAEI meetings I have been to, and it was always answered that how much damage can NM really receive if it is in the back of a cabinet, you would have to really have to through something in there hard to damage it, maybe not a good idea to located in a knife drawer, but if common sense is used I don't see the problem.

I think the key there is that it would be damaged, not that it would take a lot to damage it, but that it could be damaged. my lamp cord, well I know its there, and what its for, it is also flexible and made for such use, NM /"romex" is not made to be used as lamp or appliance cords.
I took this as an open cabinet, where tossing some pots could result in hitting the wire, reason why I would protect it, Kinda like my drop in range, its wired with the armored cable, not a NM jacketed.

I have been on job sites where a contractor had run NM across the road for power, and cars and trucks run it over all day and yes it fails after a couple days of this but just the fact it last a couple days of this torture is amazing.

Yes indeed it is very durable wire, I have run 12/2 from a saw pole to a house over 150' and left it for the duration of the job, although i would turn the breaker off when I left for safety.

This was just my take on this. If I had a better visual of the cabinet/installation of where it was going i make have a different opinion.

 

[macmikeman]

Truly, the use of a distinctive wood molding, visually significant by virtue of milled lines at each edge, covering romex in such places as the inside of cabinets in order to provide an attractive enough, yet, physical protection from pots and pans should be allowed by the code, but sadly is not. Yep, I'm talking about good old fashioned wood molding, not seen anywhere else outside my back yard for 50 or 60 years. It actually does a very fine job of protecting romex cables from all but the untrained who are not familiar with it, do not recognize what it is covering, and proceed to sawsall their way thru it... A truly fine product, sold at your nearest City Mill store...

 

[glene77is]

Ulmlaut,
One phrase of advice comes to mind:
"If you can hit it with a hammer, then put it in conduit."

 

[wireguy8169]

Wiremold box

Wiremold box

In the past I have used a wiremold box for that reason, I put a nylon nm connector in the back plate of the box , pull the cable through the connector mount the back plate to what ever is back their using either anchors or screws depending on whats there. Just make sure the box is the correct size to cover box fill. Put the box on the back plate and good to go it is sorta in the way but its better than not having it IMHO

 

[infinity]

Subject to physical damage is well, subjective to the person inspecting it. One thing to note is that if it is determined to be subject to physical damage then the code is very specific as to what can and cannot be used to protect it. So running it through a piece of ENT or sch40 PVC would not satisfy the NEC.

334.15 Exposed Work.
In exposed work, except as provided in 300.11(A), cable shall be installed as specified in 334.15(A) through (C).
(A) To Follow Surface. Cable shall closely follow the surface of the building finish or of running boards.
(B) Protection from Physical Damage. Cable shall be protected from physical damage where necessary by rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, or other approved means. Where passing through a floor, the cable shall be enclosed in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, or other approved means extending at least 150 mm (6 in.) above the floor.
Type NMC cable installed in shallow chases or grooves in masonry, concrete, or adobe, shall be protected in accordance with the requirements in 300.4(F) and covered with plaster, adobe, or similar finish.

 

[Dennis Alwon]

I have always sleeved my nm to a disposal in carflex. It is true that carflex is not a suitable form of protection from damage. Quite frankly, I don't see what one will do under a cabinet that will damage carflex. In most cases I see exposed nm cable feeding the disposal. I guess it is okay around here.

In an upper cabinet where the wire is exposed and dishes etc will constantly get banged into it I would protect it more for looks than anything else. I think exposed nm is not as neat as a sleeve of some sort over it. Check with the AHJ as they all have their own idea of protection.

Heck we use carflex to a/c units where it is subjct to damage out there.

 

[iwire]

Heck we use carflex to a/c units where it is subjct to damage out there.

Well that is a violation regardless of it being allowed or not. :grin:

 

[Umlaut]

Subject to physical damage is well, subjective to the person inspecting it.

I guess this is the answer I come to. The NEC isn't clear about this issue, and it's impossible to tell what really meets code without actually asking the AHJ or the inspector.

For my work, if a cable is installed on the top of the inside of a cabinet, I put it in cladding. I figure that it's easy to leave something poking up in a drawer that would drag across that surface and pierce the insulation.

For a cable in the back of an open cabinet, such as from the wall to a box for an oven whip, I don't put it in cladding unless the installation is particularly tight--that is, unless the installation of the oven has a shot at gouging the cable.

For a cable in the back of a cabinet under the sink for plugs for a dishwasher or disposal or instant hot, I have usually used cladding. But now I think I shouldn't have bothered. But after reading the code, I'm not sure what the right answer is.

Does it really just come down to the whim of the inspector?

Of course, if its stapled in a vertical direction, where nothing can hang on it, I'm not sure. I wouldn't do this, I would install the wire in the wall, if this was not an option, the wire would be protected by flex of some sort.

So, I guess many of this do this as practice. But does it really fit the letter of the code, as specified in 334.15.B? "Flex of some sort" is not among the listed choices: "rigid metal conduit, intermediate metal conduit, Schedule 80 PVC, or other approved means".

If an inspector were to fail an install because of the exposed NM, then would putting some flex over it really help? What section of the NEC says the flex makes the installation acceptable?

 

[infinity]

If an inspector were to fail an install because of the exposed NM, then would putting some flex over it really help? What section of the NEC says the flex makes the installation acceptable?

Yes, you've uncovered the conundrum. If the NM is not permitted by itself then it's not permitted with a piece of flex for protection either. The former means that it's subject to physical damage, the latter does not satisfy the protection requirement.

 

[Dan coulstring]

rigid metal conduit, intermediate metal conduit, Schedule 80 PVC, or other approved means

Aren't the examples just that examples. If the particular wireway is UL listed in its description as providing protection for conductors and cable ssemblies then dosn't that mean it is allowed.

 

[Umlaut]

rigid metal conduit, intermediate metal conduit, Schedule 80 PVC, or other approved means

Where do I find approval for the technique of slipping on flex, and only attaching it at one end? Or are you saying the approval of the install and permit means that the methods employed at that install are "approved means"?

I think the approval only applies when the conduit is installed correctly. According to the NEC, "correctly" means terminated to a box with proper fittings at both ends. That would mean from a box under the sink in the cabinet, all the way back to the distribution panel, in most cases. Do people really do that for residential kitchens?

 

[infinity]

rigid metal conduit, intermediate metal conduit, Schedule 80 PVC, or other approved means

Aren't the examples just that examples. If the particular wireway is UL listed in its description as providing protection for conductors and cable assemblies then doesn't that mean it is allowed.

IMO, no. The list in inclusive. A piece of metal may be another approved means. As an example a piece of ENT is, IMO, not.

 

[Dennis Alwon]

Well that is a violation regardless of it being allowed or not. :grin:

Are you saying carflex is a violation to an ac unit? I was just saying that anything outdoor exposed is subject to damage, IMO.

 

[glene77is]

Subject to physical damage is well, subjective to the person inspecting it. One thing to note is that if it is determined to be subject to physical damage then the code is very specific as to what can and cannot be used to protect it. So running it through a piece of ENT or sch40 PVC would not satisfy the NEC.

Infinity,

True enough.

If the HO is the person determining the requirement of 'protection',
then the response could be different from what the NEC requires.
As you stated, "...subject to the person inspecting it."

That brings up an interesting point (in my mind).
If the requirement for protection is not actually a determination of an NEC requirement,
but rather of an issue to be resolved for satisfaction of a customer (his concern or aethetics),
then would the installation have to exactly according to NEC ?
I can't come up with a suitable example at the moment.

 

[glene77is]

Are you saying carflex is a violation to an ac unit? I was just saying that anything outdoor exposed is subject to damage, IMO.

Dennis,

I think you are right. Protection is protection.
But, in this area, Smurf Tube is sometimes allowed from the AC disco to the compressor unit ! Could not believe it when I saw it. AHJ said it was OK!
I have difficulty imagining that Smurf tube is good for anything
except behind a wall, protected by the wall.

 

[Hendrix]

There are days when I feel like I totally understand the code

Oh, really

 

[Dan coulstring]

I think the approval only applies when the conduit is installed correctly. According to the NEC, "correctly" means terminated to a box with proper fittings at both ends. That would mean from a box under the sink in the cabinet, all the way back to the distribution panel, in most cases. Do people really do that for residential kitchens?

Are you saying that anytime you use a piece of conduit as a sleeve for protection it has to have a box and fittings at both ends. I don't think so.

300.15(c) No box required when conduit is used for support or protection.
Where does the NEC define the word correctly? I couldn't find in Art. 100