Is it ok to route romex behind base cabinets?
It’s by no means elegant but is there a code violation here?
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Replies
Depends. In new construction it would be a violation because of insufficient clearance for nails.
If it was fished in after the walls and cabinets were set it wouldn't be a violation in my opinion. Different set of rules.
It's a fishing situation, walls and cabinets are in.
Thanks.
What type of boxes are in the wall?
Dave
I realized I made a mistake in the drawing after I posted it. Those were not supposed to be receptacles otherwise it would have been a code violation by joining two adjacent receptacles. They are actually lighting under the wall cabinets.
So there is no box, the wire will come out just under the wall cabinet into the fixture and there will be a false bottom to hide the wiring to the fixture.
Piece of MC cable would do the trick for you. not quite as small as type NM or as flexible, but should work, and provides the protection needed.
Dave
That sounds like the answer for him. If unfamiliar with working with MC he needs to make sure he gets the right connectors, antishort bushings, etc. The new connectors with bushing built-in and spring fingers to attach to the box are neat. If he has never cut this type cable may need some assistance or guidance.
The space behind the cabinet is just enough to slide in a piece of 14/2 NM maintaining the flat surface of the cable parallel to the back of the cabinet, I have never worked with MC so I don't know if that will fit into the space.
I guess I can make a recess channel into the plaster wall to accommodate the extra thickness, but in that case I could use a BX then which I am familiar with.
Can you give me a primer on MC?
I use MC whenever I have to install wire in my home, and I have to deal with existing BX. The MC is a breeze to work with relative to BX, but get the cable cutter for cutting the sheathing (HD and Blowes have the Greenlee cutter). I have to use a hacksaw to cut BX sheathing, it comes off MC easy with the cutter. You can't make tight corners like with NM but it's easier to bend and lighter than BX. And it has a grounding wire
Can you shed some light on the connectors and bushings that RASCONC was talking about?
By bushings I guess he means those red things to protect the conductors from the sheathing, same as BX. By connectors I guess he means the right clamps, I look for the ones at HD that say "MC" or "Flex." I think they have lips on the opening to prevent the sheathing from coming into the box, but they don't have the screw that BX clamps use to bite into the sheathing. Instead clamps down on the sheathing like NM.This is surmise based on observation, better wait for a more informed opinion...No idea about the newer stuff he mentions....
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This is the style Iwas talking about, the aluminum ones are all you need.
http://www.aifittings.com/whnew8.htm
Edited 4/21/2005 10:10 am ET by RASCONC
MC cable with #12 wire is 3/8" diameter. Much smaller than greenfield type armor cable that you have to fish the wire through.
The box connectors that were referenced in another post are quick connects. The ones we use are called Snap-2-it, made by Arlington Industries. I tried their web address, http://www.aifittings.com, but got no hits on a Goggle search.
The fittings have spring clips that snap into the box, and another set internally that snap over the cable. Once in place, they are a mo to remove. A little pricey for a box, but woth it in time savings when installing on a big job.
The cutter I use is a Roto-Flex by Seatek Co. Haven't check their web site; http://www.SeatekCo.com , so don't know if it is still up. Greenlee also makes a similar cutter, and as mentioned may be available at a big box. Basically they are a hand clamp with a cutting wheel, preset to a certain depth, that cuts only the metal , leaving the wire untouched. One or two quick spins of the handle, the armor cable is cut and you just twist off the end. leaving the tail of wire you need in the box.
You can do the same thing with a hack saw by cutting at a 45 degree angle across the spirals of the cable. You just have to be careful not to nick the wire with the saw,and cut only one complete spiral.
Mini lesson complete.
Go forth,practice and prosper.
Dave
For planning purposes most brands, as measured in the field, of #12 MC are just about 1/2" in diameter. Particularly when cut and the armor unwinds a bit. Just about as wide as #12 NMB measured the long way across its oblong cross-section. Minimum practical size hole in a stud is usually 5/8". 3/4" is better for snaking runs through multiple studs or holes. Second MC is not needed in this case. MC is not effectively armored versus drywall screws or nailguns if the cable is restrained as it is at holes in studs and, in this case, trapped by the back of a cabinet. Where it is flopping around a stud bay unrestrained nails tend to push the armor away from them. Why anyone would want to fire a nail into a stud bay, where it would be unsupported by a stud, is anyones guess. MC wouldn't be any advantage. A run of NMB will fill the same function while complying with the NEC. The AHJ may have different requirements.Third first thing I do on a job with flex or MC is tell the helpers toss their armor cutters. Rotary cutters are slow, potentially dangerous and an unnecessary tool. I have timed this process and with minimum practice the MC can be cut at faster and better with dykes. Also the nature of the cut itself is superior with dykes. The rotary units often leave a burr pointed directly at the wire insulation. I have seen the insulation cut before a bushing can be installed. With dykes the metal is less cut than pinched and snapped leaving a a square edge with no burr. Any edges are running perpendicular to the insulation. The rotary cutter itself, if not perfectly adjusted, often nicks the insulation. This depth setting has to be readjusted. As brands, batches or roughly handled MC ends can all have different diameters. I have particularly seen this where a run has been fished through difficult spots. Give dykes a try. Once you learn the method you can save the cost, weight and bulk of the specialized cutter. The general method: Ends of runs are cut with Kleins or dykes. Then the armor jacket is made accessible where your connector is to go by snapping the armor while forcing slack between the hands. The resulting small loop is then cut at a slight diagonal close to the where the connector is to go with dykes and the sharp tip cut off. The end is then tucked back into the end of the armor. If your good the dykes can be rolled slightly and even the dull edges directed away from the conductors. Also when the end is dressed the opening can be further smoothed by opening the dykes fully and using the cutting edge as a scraper to remove any burr left by the manufacturer. A bushing is then inserted and the connector installed.Takes me ten minutes to demonstrate the technique and get them to do a couple. I have yet to see one go back to using their rotary cutter.
Is that for aluminum based cable.I was a kid when I last worked with BX and it was all steel and I don't think that you could cut it with dikes.
Galvanized steel.I'm only cutting across the a single piece of the steel tape that makes up the armor. A sharp set of dykes, the bent head ones seem to work better for some season, can cut right through the stuff if you have a good grip. More often than not it partially cuts and crimps a track that snaps when bent. Aluminum armor is easier to cut than the steel but even the thicker steel of galvanized steel flex gives up quickly when crimped, partially cut, and bent. The edges of the cut concentrates stress within the metal and metal fatigue causes the tape to crack when bent sharply.Once you get used to it it becomes automatic. Steel does demand more of a grip. But nothing superhuman or exceptionally taxing.A few times I have been called in to straighten out circuits run in MC that had insulation faults because of rotary cutters not properly adjusted or used on MC. PITA tracking down faults, restripping if we have slack or running new MC if we don't. The really frustrating part is that you can troubleshoot today clearing all faults but, assuming you don't check every connector very carefully, have more faults show up in time as more skinned insulation makes its presence known.Rotary cutters have a place when running heavier flex runs on a production basis. Without the conductors in the way they can work at maximum speed without messing with adjustments or having to closely examine every cut to see if the insulation is damaged.I use bent-head dykes but a friend had a set of Klein cutters, looked up on their site and they list them as 'All-purpose shear and BX cutter' model #1104, that had more of a bypass cutting action than the dykes. It makes them a bit less adaptable for cutting wire, pulling staples and for manipulating stuff but they cut the armor on MC, flex and BX quite well. Maybe one day I'll buy a set. Could be useful if I had a job where we were running a lot of MC. But here again for small jobs and service work I tend to go with the ten or so tools on my belt instead of running out to the truck. Another reason to have another way of doing it than depend on a specialized rotary tool. That and and it doesn't fit in my pouch or back pocket very well.http://www.kleintools.com/I think this only takes you to the Klein site. Look under: Product Index > Cable and Bolt Cutters > Cable Cutters > 1104 Maybe one day I'll get a set of these.The dykes I use are D2000 - 48s.: Product Index > Pliers > Diagonal Pliers > D2000-48 Given a choice it always pays to get he 2000 series. Cutting a drywall screw can make your 300 series pliers or dykes into strippers.
Lorn, it comes around in full circle. I'll use NMB for the limited space behind the cabinet. Thanks.
Costs me money to come to this forum, I have to get one of those dykes because they look so cool. Hmmm what color should I get.
Dave and RASCONC, I learn something new about MC cables which may just come in handy someday. Thanks.
As far as I know the bent head 2000 series dykes, with induction hardened knives that won't dimple when you cut hard wire, only come in dark blue.Ideal makes a similar model, also with the hardened edges, with a yellow handle.Channellock makes a good one with a light blue color.I suspect all of these are made in the same factory with the manufacturers marks being stamped on and their preferred plastic handle color applied.Any dykes, linesman's pliers or similar really benefit from the induction hardened cutters. Always sad the see a new guy who buys the unhardened version when he tries to cut a drywall screw and it dimples the edge creating a stripping hole. Kind of takes the shine off.Of course even hardened knives are subject to damage if you cut a live circuit under load. Klein tools are good, solid, reliable tools. Only thing they haven't figured out how to make, and I hear they may be improving on these counts, is knives and hacksaw blades. The knives won't hold an edge. Use it for ten minuted and a two year-old could safely run with it. The hacksaw blades spit teeth like PeeWee Herman in the the ring with Ali.
I do use dykes and the technique you described.
I have also use the rotary cutters extensively over the past ten years, and never had a call back to trouble shoot any connections.
As you have pointed out on many occasions, quality of work isn't in the tool, it is in the hand that uses it.
Now ask me about the journeymen electricians form our brother local, that work for some of the contractors we use. A lot of the quality work, or lack there of, seems to be a culture associated with specific companies.
Good or bad, I learn from both.
Conversion to electrician from and old carpenter is slow and difficult. Must be all the saw dust between the ears :)
Always good to hear you describe techniques, and explain this trade in such a clear, understandable manner. That is another skill I need to work on.
Dave
Could someone please explain the difference between MC and BX? Around here it seems that BX is the 'old style' of armored cable and MC is the 'modern' style. In fact, in the big boxes I think that I have only ever seen MC...or at least thats what I thought it was.
Maybe someone could give me a rundown on the different armored cables?
Daniel Neuman
Oakland CA
Crazy Home Owner
doc,MC = metal-clad cable. It is a factory assembly of insulated current-carrying conductors and an insulated equipment grounding conductor (EGC), in a spiral metal armor/sheath. The armor has to be bonded (i.e., connected to ground) at each end of each run (usually by being connected to a metal box that's bonded), but it does not serve as the EGC.BX = armored cable, proper abbreviation is AC. A factory assembly of insulated current-carrying conductors in a spiral metal armor. There is a metal tape running lengthwise inside (and in contact with) the armor. Used to be, the armor and bonding strip were allowed to serve as the EGC for a cable run of any length. It was discovered that often the pathway through the armor/bonding strip was if sufficiently high impedance that it wouldn't carry enough current to clear a fault (trip the breaker). Now if the length of the AC run is short (6 feet or less, in a fixture or machine whip), the armor/bond tape is considered a good enough grouding path, so AC is Code-approved.I think it's only a matter of time before AC use is eliminated entirely. My AHJ (by regulation) banned use of AC for general branch circuit wiring years before the NEC did. The only thing AC has going for it is that it's faster to install. One less conductor (the EGC) to connect.Cliff
Thanks Cliff,
I don't understand why anybody would want to use AC. AC seems inherently dangerous. I bet its not even legal to use here in CA.
Daniel Neuman
Oakland CA
Crazy Home Owner
My impression is that BX was installed before anyone thought grounding was important. Grounding via the armor seems to have been a retrofit. I have seen it work though. I don't know why AC continues to be used, I think there are even steel versions of MC.Ya gotta love the hacks that come along and leave BX splices outside boxes, since the metal box is part of the grounding path for spliced BX cables. At least they didn't waste a dime on a plastic box....
Yes, it appears to be a violation because the romex is not protected within stud bays. The better choice would be to use BX armor cable instead.
Jim
I don't know if other places have this as code, but here in Columbus you have to run a seperate ground when using armour cable or metal conduit.
you have to run a seperate ground when using armour cable or metal conduit.
Used to be you could use the armour cable sheathing for grounding but the code changed a long time ago. I think it's pretty well a national thing now.
BX would have been my choice but there is not enough room at the back of the cabinet for it. Just one of those situations.
Yes, it appears to be a violation because the romex is not protected within stud bays.
??? I don't see anything in the NEC that requires this. In fact, it explicitly says that NM (Romex) is permitted for exposed work, provided you meet conditions for following surfaces, suport, and protection from physical damage. And if you're fishing it, you don't even need to worry about supporting, or following a surface.