I have seen different reads on this in various forums. I am posting some examples of what IMO is code compliant.

I am very interested in others opinions on this.


Picture One.

I believe this to be code compliant.

The nails pass through the interior within 6 mm (1/4 in.) of the back of the enclosure.
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Picture Two.

I believe this to be code compliant.

The nails pass through the interior within 6 mm (1/4 in.) of the ends of the enclosure.
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Picture Three.

I believe this also to be code compliant.

The screws do not pass through the interior at all, the screws pass through the exterior of the enclosure.

That is my interpretation of this rule, so bring it on how do others see it.

I do not use any of the above methods for mounting I am just curious.

OK I have put screws in a 4" sq as shown in picture three.

Bob




[This message has been edited by iwire (edited 10-09-2004).]

I agree on all three! And if I may...
If pic's 1 -3 were Non-metalic boxes, I would see it as a violation. As the screws or nails could conduct outside the box without tripping the breaker for the circuit.

I'm not sure that picture #3 reflects the intention of these holes. I read some place that those holes are not there for mounting the box. I would not write a violation for installing a box this way because I've done it that way myself. Maybe someone else has some information on the use of these holes. I seem to remember that those holes had been used for dipping the steel box in the galvanizing process originally.

1 and 2 comply, 3 does not, in my opinion

I find this discussion interesting in that it makes me wonder if a job I encountered some months back should have been rejected. In between the time the inspector approved the rough in of an addition the homeowner decided he wanted the receptacles lowered since now he was going to install tile 12 inches up the wall and the receptacles would have been partially out of the tile area. So, without notifying us he cut the nails holding the one gang plastic boxes to the studs and we came at finish to find the boxes dangling behind the drywall. Although we should have said "enough of this" and walked, we proceded to put drywall screws through the side of the boxes into the studs. The cables just barely made it into the boxes. Should this have been a violation and the customer made to open the walls?
iwire, I hope I am not taking attention from your question because it seems related but this is important to me since we are scheduled to take this customer to court next month to collect funds we feel he owes us for tampering with our wiring.
I myself have anchored boxes using methods id'd in 1, 2 and 3 and never rejected. I find this interesting.
Thanks
Ron

Ryan


I do not understand why you feel this way, I am not saying you are wrong I just need some more info.

The key to this in my opinion are the words:

"pass through the interior"

The screws in the side of the box do not in any way pass through the interior of the enclosure.

Pass to move in a path so as to approach and continue beyond something

Through used as a function word to indicate movement into at one side or point and out at another and especially the opposite side of <drove a nail through the board>

Interior the internal or inner part of a thing

All the definitions came from the Merriam-Webster On line Dictionary.

So that is why I have a hard time with this article, we would have to change some of the definitions in order to enforce the section the way you want to.

That said I will keep an open mind, maybe I am missing something.

The 2002 handbook is no help at all for this, I would call the handbook commentary after this section gibberish.

2002 NEC Handbook 314.23(B)(1) Commentary.

Huh?

Bob

By the way some may feel I am pulling apart the code and trying to find ways around the NEC.

That is not the case at all, the CMPs choose certain words for a reason, in this case they chose words that IMO suggest the section only applies to nails and screws that literally pass through the inside of the enclosure.

I can't remember the whole thing but Charlie E has said more or less;

When you read a code section do not read it like know what it says...even if you wrote it.:

Bob

Okay, let's for the sake of this discussion, say that photo #3 represents an incorrect installation for what ever reason. Does anyone know what the intended use is for these holes? Come on Tedesco, you should know.

Bob
You are correct in saying that CMP members do use specific language. But remember that some of the requirements go back to the past before some of the methods today have been encountered or thought of.


I was at the Eastern section meeting this past month and there were several CMP members present. It is informative not only to hear the code issues, but to talk to them and hear how hard the process can actually be.

This very subject of how the support of boxes was brought up, and they used some slides and open conversation to discuss this.

Boxes, especially plastic boxes are not designed or "tested" (the key here is 'tested') to be supported by the wall of the box from the inside of the box. Because of the non tested part and the fact that manufacturers will not say it is to be installed in that fashion, it is a violation.

They also brought up another interesting aspect of the nails or screws installed through the box within 1/4 inch from the back - that if a screw is used, the threads pose a hazard to the conductor insulation, and require a sleeve over the shank of the screw threads that pass through the box. So much for using screws through the box.

Pierre

Pierre this is really getting to be a mess.

I agree that plastic boxes are weekend by using screws through the side, but are the holes for mounting required to be tested for the purpose?

I run a lot of metal wireway, the fact that it is made to be customized leads me to drill my own holes for mounting the wireway and when you shorten one up you need to make your own holes for the fitting you will be putting on.

Are you telling me all this is a violation.


I agree this is could be an issue but what do you mean by "So much for using screws through the box."

314.23(B)(1) says we, can no room for discussion.

Ryan mentioned that the 2005 314.23(B)(1) has been changed, does the new wording say screws?

Lets stay on target why did they use the words "pass through the interior" if that is not what they meant?

And if that is not what they meant that is a problem because that is what it says. Intent is not enforceable the written words are what is enforceable.

By the way if I sound upset or mad I am not.

I am still just trying to get some answers.

Bob

Hi Bob. Let me start by quoting the 2005 text.


Now, back to the question at hand. When I read the code, it gives me two options on how I can support a box with internal screws.

Option 1: I use brackets outside the box.
Option 2: I use screws that pass through the box, within a 1/4" of the back or ends of the enclosure. In your example 3, the screws, in my opinion, are not passing through the box...they are peircing the side of it. Also, even if they were passing through the box, they are not within a 1/4" of the back or ends of the box.

Ryan - I'm with you on this one.

IMHO, if you used screws that passed through the interior of the box, they would have to have their threads covered, and be within 1/4" of the ends or back of the box.

The screws in pic. 3 are not paasing through the interior of the box. Since they are not passing through the interior, they do not need to be within 1/4" of the ends or back. Since the threads are not exposed, they do not need to be shielded.

The only other way to mount non bracket-equipped boxes would be to mount them to a board tacked between the studs by screws driven through the back of the box.

OK so for 2005 it is clear screws are out unless protected by sleeves.

This also proves that they are taking about screws that pass through the interior of the box. If the screw did not pass through the interior it would not need protection.


OK so the following box is a code violation, the screws do not pass through the interior of the box.



I maintain that 314.23(B)(1) as written now or in 2005 only applies to screws that pass through the interior of the box.

If it applies to all box mounting methods the common mounting method is a violation.

As you said before in another thread "by using the English language" can you explain what part of the screw in the 4" sq above passes through the interior of the enclosure.

Please remember to just read the words in the section, not read what you want it to say.

Still just a curiosity for me while I am sitting here babysitting watching Sponge Bob.

Bob

The way I am reading it is that you are only given two methods in which you are allowed to mount the box. You can use brackets, or,option two, you may use screw that comply with the following:
they must pass through the box, and
they must be located within 1/4" of the back or ends of the box.

BTW: Squidward is my favorite spongebob character....he reminds me a lot of me!

[This message has been edited by Ryan_J (edited 10-10-2004).]

I guess that would make me Mr Crab.

Although I've never called this, I think my reading the literal text of the code, using the holes in the back of a four sqaure box would be a violation as written. I don't think this is the intent and that is why I've never written it, but that is the way the literal text reads. In my opinion, if the nail or screw penetrates the box within a 1/4" of the back or end(s) of the box, I see no problem. I think when the screws penetrate the side of the box in the center of the box it is a problem.

Sometimes the CMP will not have control over the final language that is presented in the actual text of the NEC. I do not know if this is the case with this wording.

I do not know if we can get a response from the manufacturers, but it cannot hurt to try. I will email a couple and see if they respond to the use of the 'holes' in the side of a metallic box.

For one, I would never pass the use of screws or nails supporting a plastic box mounted from the inside of the box, except for the new (listed) Smart Box.

I have used the holes in the back of 1900 or 4/11 box, but not the side - that is what a bracket box is for. I have mounted the others on walls and ceilings many times.

Maybe the holes we see on the side and towards the front of the 1900's is for mounting 'ears' so the box can be mounted in an existing wall???? Did you notice that they are smaller than the holes in the back of the box?
Bob
You asked if the holes have to be tested for listing, I am not sure of the actual wording for the listing/testing standard, but I would think so - just my opinion.

Pierre

As to the supporting screws through the back of a 4s box, if this is indeed a violation, how are we to mount Exit Signs and similar things on the Tile of an ACT T-Bar Ceiling?

What I mean is the SOP (Standard Operating Procedure) is to hang a 4s Box (with a 3/4" Raised 3/0 ring normally) from a 24" Span Box Hanger (Caddy number 512 to be exact!), utilizing 1/4" &#215; 20 Screws through the Box, landing into Box Clips (Caddy BHC).
Complete Assembly is only mounted via screws through the back of the Box (and "Backed-Up" with at least one #12 Ceiling Wire, in case the Ceiling and/or Tile becomes "Suspendedly Challenged").

Sure hope this type of Installation is not a Bozo No-No, because I have installed literally Thousands of Exit Signs this way!
I try to avoid doing things that appear as if the Three Stooges performed the Installation (or stored the Materials, noted the Plansets, keep the Job Cards and Approved Sets in order, keep track / order of Tools, Manage the Project,...), so "Going Bozo" is totally not in the agenda!

Not mad, just asking questions

Scott35

I think we can get carried away on the listing issues.

Where does it end?

Seriously, 'listed' mounting screws, listed holes in the studs.

Let me ask this are the 8-32 ears in a 4" sq 'listed' or tested for mounting the box?

I hope so because we do not buy any bracket boxes, we use a Caddy H-2,3 which mounts between the plastering and box using the 8-32 ears to hold the box, ring, device etc.

The only time I write up 314.23(B)(1) is when screws are inside of a plastic box.

That doesn't fix the poor code langauge of the section though.

It seems that the way Ryan is reading this is that there are only two methods of mounting a 4 square box: 1] Use brackets or 2] use nails or screws which pass completely through the back of the box from one side to the other [and if screws, they must be protected by sleeves]. Objection to 1]: there are many 4 square boxes made with out brackets. Objection to 2]: Holes [and sleeves] are not provided for 6" nails or screws in the back of the box. Next Ryan would object to field drilling such holes for violating some UL listing.
The point is to read between the lines. What is safe and what is dangerous? The box must be securely supported. Fasteners run thru the middle area of the box would interfere with the wires. Putting screws thru the back and/or sides provides a solid support and will not interfere with with the wiring.
If you can bolt thru the back of the box [Caddy bars] why can't you go thru the sides. Other than mounting every bracketless 4 square box with rigid pipe and double lock rings, how can any of the dozens of 4 S boxes be legally mounted?
By the way, what exactly is the "end" of a 4 square box?
Note: I have found that the little holes in the sides are the right size to use a self threading, 10-32 ground screw. This helps when following idjiots who powder nailed the box to a concrete wall and didn't carve a niche into the concrete behind the furnished tapped hole in the back.
~Peter

Peter: Notice that I have written several times that I don't enforce this section the letter of the law. I am just bringing up the fact that that is what it says.

Ryan

But that has been the whole point of this thread, what does it say?

It talks about nails or screws that pass through the interior. In the English language that would mean in one side of the interior and out the other side of the interior.

Nothing about screws or nails passing through the exterior of the box.

Hey Gents, I'm back.... 1/4" from the back or end of the box, I would say pic #3 is covered! In a 4 square, what is the end? The Top, bottom, left or right end???? Even through the back, it's through the back end, right? In either, or niether case is it though more than 1/4" into the interior wiring space. i.e. it doesn't interfear with the function of the box, right? No! I believe that to be the intent of the wording.

How-ever, years ago, I had an Inspector get me on a plastic box, stating that screws from the inside would allow voltage to be conducted out-side the box, (un-checked) and thet wasn't Kosher to him, and I agree. But mounted firmly from inside anywhere in a metal box, so long as it doesn't interfear with the function of the box, is hip with me. (Not that I count!)

I believe that the holes opposite the opening (the back) of a 1900 box are designed for using different methods of securing and supporting the box.

I do not believe the small holes they provide on the side of the box are designed for mounting, but I cannot say I know that for sure. We need a manufacturer to state what the intention of the holes are for.

I have seen additional holes drilled into the side used for support, I have also seen the KOs removed and a screw and washer used for support.

I have also seen KOs dditionally 'holesawed' and 'knockedout' in these same boxes.


I am not saying these methods do not work, but have these boxes actually been designed for those purposes - maybe yes, maybe no.

What makes me laugh is how passionate some peope get for some of the different topics we discuss here - notice how I say discuss- as that is what we are trying to do.

I will say that I have used certain methods I learned in the field and seen here that they are not really permitted - that is the beauty of these sites.


Think about this:
When mounting a box in a suspended ceiling, say to a junior beam, we usually mount it through a hole in the back of the box and then leave many of the KOs for entry from any angle the cable/conduit may come from.
Normally we mount boxes on framing with bracket boxes, the brackets designed for the mounting purpose.
The 'ingenuity' of men/women in our trade has led to many manipulation procedures over the years to help installations, when we either run out of the proper equipment or when no equipment has been designed for the purpose at hand. Some of these manipulations have become standard practice, some have even led to the evolution of new equipment - with the latest that comes to mind, the Smart Box.

Pierre

Just got back from the supply house, where I bought some rivet guns before you guys thought of it and caused a run on them.

[This message has been edited by watthead (edited 10-11-2004).]

Peter............Are those holes in the side that you use for grounding, marked for grounding use? If not that too could be a violation

Peter:
4" Squares are now in the marketplace here (NJ) with 'dimpled' marked tapped holes for grounding screws to prevent your scenario of the Hilti installation.

Personally, I have never seen anyone put a grounding screw in the 'side' holes, and some may say that is a technical violation; the rear tapped hole has a "grd" marking stamped in by the mfg.

So much for splitting hairs!

Bob; MHO on your original ??; if the box is mounted thru the side holes ie: pic#3, I would not have a problem with it, as long as the box is flush/square/plumb and secure.

John

Velect,
The holes are not marked for grounding, but in the situation I was referring to, the standard hole was unusable. It seems reasonable that it would be legal to drill and tap for a 10-32 ground screw. I just noticed that those holes in a 4" sq. box happen to be the right size thus eliminating the drilling step. Using a thread-cutting ground screw, such at a Dottie #1032TC, eliminates the tapping step. The holes in a 4 11/16" box are too big.
Now I suppose Don Rescapt will come along and question whether the holes provide for a 75% thread.
~Peter

OK, what do we do if we have a 4x4x4, 6x6x6, 6x6x4, or a blah x blah x blah, Appelton, Hoffman, or similar manfacturers box with no factory holes at all?

Roger

Throw them in the dumpster, they can not be used.

Darn!

Roger

I think the commentary in the handbook is on the money here. The nails or screws can't be where they would interfere with a device.

I often mount a deep 4 X 4 box against a stud...knocking out the center hole and screwing in a fender washer with a deck screw, then drilling at least two holes through the same side to install some additional deck screws. It's very secure and the screws don't interfere with the installation of the device.

I think this is a case where the legal language of the NEC makes intent as clear as mud.

Dave

This is starting to look like the "Lets talk about screws some more" thread, but less ugly. No one has gotten adimate about it yet. Because no one knows what those holes in the side would be for if not for mounting.

Personaly, I can not see any other purpose for them.....

I would believe "manufacturing expediency" as much as anything else. They may be used in the manufacturing process or they just share a machine that also makes another style of box.

I don't really have an opinion about using them for mounting. I agree with the other poster. If it is securely mounted and in compliance with the other articles it would be fine with me.