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

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" × 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.