Arnored Cable

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Re: Arnored Cable

George I never said that 300.4(A)(1) & (2) apply to this installation I was just pointing out that in general the NEC requires at least 1.25" set back of wiring methods that are concealed and could be damaged by nails or screws.
Yeah, I thought about retracting that and forgot.

Just figured I'd pitch my hat in... :)
 
Re: Arnored Cable

George
There are so many variables to installations, generalizing that GC's control rockers is absurb.
The rockers work by the board and if they only have longer screws left to finish the last few boards, guess what...
Somewhere in my photo databank, I have a picture of a length of AC that has 2 nails driven through it about 16 inches apart, the breaker was only tripping every day or so. Eventually that would have started a fire.

Pierre
 
Re: Arnored Cable

Anything can be damaged by screws.

I've had to dig EMT out of sheetrocked metal stud walls where the cabinet maker hung a screw traight through EMT. Yet no nail plates apply nor does the setback of 1?".

One can drive a nail through any Rigid Metallic Conduit with a powder actuated driver which is what I'd use to hang my picture to a brick wall :p

The fear of what might possibly happen is different than what is happening during construction. 300.4(A) is also governed by 300.1(A), which, I maintain, is trump.

AC is armored. . .and has a long history of installation in what used to be covered, until the end of the 1990 NEC, as Article 344 - Underplaster Extensions.
 
Re: Arnored Cable

Art. 320.10 Uses Permitted(4) "Embedded in plaster finish on brick or other masonry, except in damp or wet locations."
How could this be done with a 1-1/4" set-back from the finished surface? 1-1/4" thick plaster? 320.23(A) and (B) do not require the same protection as NM cable such as guard strips or running boards. Reading 320.10 as it is would seem to allow the original poster's method. I have seen it done this way a few times in the remodel of old historic buildings where all of the interior walls were solid brick with plaster finish. I wouldn't prefer to install AC this way but I am not convinced it is a code violation. 320.10(4) should say "Embedded in plaster finish on brick or other masonry with proper protection from physical damage, except in damp or wet locations."
 
Re: Arnored Cable

iwire posted January 16, 2005 01:34 PM

I was just pointing out that in general the NEC requires at least 1.25" set back of wiring methods that are concealed and could be damaged by nails or screws.
Bob, the NEC is only "in general" about some concealed wiring methods in some types of construction.
300.4 Protection Against Physical Damage. </font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">(A) Cables and Raceways Through Wood Members. </font>[list:37ffeb77bb]</font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">(1) Bored Holes .</font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">(2) Notches in Wood .</font>
<font size="2" face="Verdana, Helvetica, sans-serif">[*]<font size="2" face="Verdana, Helvetica, sans-serif">(B) Nonmetallic-Sheathed Cables and Electrical Nonmetallic Tubing Through Metal Framing Members. </font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">(1) Nonmetallic-Sheathed Cable.</font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">(2) Nonmetallic-Sheathed Cable and Electrical Nonmetallic Tubing.</font>
<font size="2" face="Verdana, Helvetica, sans-serif"></font>[*]<font size="2" face="Verdana, Helvetica, sans-serif">(C) Cables Through Spaces Behind Panels Designed to Allow Access .</font>[*]<font size="2" face="Verdana, Helvetica, sans-serif">(D) Cables and Raceways Parallel to Framing Members .</font>[*]<font size="2" face="Verdana, Helvetica, sans-serif">(E) Cables and Raceways Installed in Shallow Grooves.</font>[*]<font size="2" face="Verdana, Helvetica, sans-serif">(F) Insulated Fittings.</font>[/list:u:37ffeb77bb]<font size="2" face="Verdana, Helvetica, sans-serif">
300.4(E) is very specific in its language in describing the condition of installation. . .It does not say
Cable- or raceway-type wiring methods installed in a groove shall be protected by. . .
Rather it limits the groove to one that is to be covered by very specific construction
Cable- or raceway-type wiring methods installed in a groove, to be covered by wallboard, siding, paneling, carpeting, or similar finish , shall be protected by. . .
There's nothing general about that, except that these are coverings that are generally attached with screws or similar fasteners.

A brick wall with no covering on it, an uncovered brick wall, does not fit the description of 300.4(E) or any of the other constructions described in 300.4 even if a groove is cut in it.

And on top of that, 300.1(A) says that Article 300 applies unless modified by other articles.

Now 300.1(A)'s a general statement. 320.10(4) is very specific in its modification and describes an underplaster extension to a TEE.
 
Re: Arnored Cable

Al, bold as much as you want, we each have separate opinions on this. :)

There's nothing general about that, except that these are coverings that are generally attached with screws or similar fasteners.
Installing carpeting on a wall with screws on nails is a little tacky IMO. :D
 
Re: Arnored Cable

Some say the Sixties have never died.

Shag carpet anyone. . .? :D
 
Re: Arnored Cable

By the way Al, I meant no disrespect with my comments. :)

Now is that shag green? :D

Boob

edit, the above must be one of them Freudian slips. :D

[ January 16, 2005, 07:21 PM: Message edited by: iwire ]
 
Re: Arnored Cable

Bob,

Please imagine that I install NM stud to stud in an existing wall by cutting 4" x 4" holes at each stud, cutting a shallow notch, nail plating the stud. . .the NM is running, concealed, smack up against the drywall or plaster and lathe skin of the wall.

The NM is pulled tight and stapled off. . .

300.4 is clear that I don't have to nail plate anywhere but over the notch. And it is silent about pulling tight or bending the NM back into the center of the stud bay.

After the 4" x 4" holes are patched and painted, what is to stop a screw from penetrating the NM?

Nothing.

This is a generalization that can be made in defense of the relative un-importance of the fear of future unspecified picture screws.
 
Re: Arnored Cable

No disrespect experienced.

I'm partial to orange shag. . . :D
 
Re: Arnored Cable

Hold on to your hats men !!!!!
The inspector was wrong in his interpretation of Art. 300-4 and 333

I called code enforcement in Trenton, NJ .
They had the final say in how the armored cable should be installed in grooves of brick.

No plates needed !

The depth needs to be deep enough to recess the cable !

Now the inspector is pissed, but ya know what?

I don't give a fly -in F...........

I was put through to much stress on this one.

I would have had to remove about 6000' of Bx cable.
 
Re: Arnored Cable

Originally posted by al hildenbrand:
Like I said, it's right there in the words.
OK than please help me understand why the nail plates are required when the AC is covered by carpet?

That would be put up with glue.

I still feel it all depends on the AHJs read on similar finish.

I read it as any finish that is easily penetrated like a carpet.
 
Re: Arnored Cable

Physical protection doesn't seem to be about how easily something in penetrated.

Roll back up to my 7:30 PM post near the bottom of page two.
 
Re: Arnored Cable

Al if we are not worried about how easy the carpet is penetrated what is the need for the nail plates under carpet?

If it was not for the carpet part of that section I could agree that the protection is only for protection from nails and screws used while hanging the covering, however nails and screws will no be used to hang carpets. At least I doubt that they would be used.
 
Re: Arnored Cable

Mister Max 1200
A big that-a-boy to you. In my opinion we need more contractors that will stand up to the code enforcement officials and show them that they are not the final ?Authority Having Jurisdiction? but just a hired warm body to do a job like the rest of us. Contractors wait until it is going to cost $$$$$ before doing anything and this leads the inspector to start doing his job based on the assumption that something might happen instead of taking the code for what it says. I have kept up with this thread and was waiting for some one to post that the cable should be encased in 2 inches of concrete with 5/8 inch rebar for protection, after all a drunk might drive a vehicle through the wall.
 
Re: Arnored Cable

JW you have been following this thread, can you explain what we are protecting the AC cable from when installed in shallow groves than covered in carpet?
 
Re: Arnored Cable

I always admire those who choose to hide their electrical panels behind a large picture suspended from a 16 penny nail driven straight into the SE cable. The problem with trying to idiot proof something is that often the idiots are so ingenious. :D :confused:
 
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