ECN Forum Forums Code Related Discussion NEC & other Code issues 314.23(B)(1) Box Supports.

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