2020 NEC Secured

[Aaro]

I am an electrician at a university. I have been given the job of inspecting and reporting on how one of the projects being done by an outside contractor is doing. Because of pillars in the existing building, the decision was made to stud out the wall so that no pillars are visible. Thus the metal studs only have sheetrock on one side of the studs. The electrician started installing brackets that would work for where there is sheetrock on the other side of the wall. There is a metal brace that prohibits the box from moving back any farther. However, because there is nothing to push up against, the boxes could push back from the sheetrock. I brought this up long before there was any sheetrock on the wall. I sited the NEC 2020

110.13 (A) Mounting Electrical equipment shall be firmly secured to the surface on which it is mounted.

I also sited

110.12 Mechanical execution of work. Electrical equipment shall be installed in a neat and workmanlike manner.

The electrical contractor claimed that the ears on the receptacle were part of the mounting. Is the contractor correct? Are there any other codes that would be helpful? Thank you for your input.

 

[Elect117]

Do you have photos?

There is a metal brace that prohibits the box from moving back any farther. However, because there is nothing to push up against, the boxes could push back from the sheetrock. I brought this up long before there was any sheetrock on the wall. I sited the NEC 2020

I don't really understand the layout here. Is the concern the conduit/wiring method? Or a outlet box? Or some other type of box?

The box is sticking out and not flush? Or the box is flush but improperly secured?

 

[roger]

Sounds like they are using something similar to Caddy C23 and will probably be fine but you can suggest that they use TSGB's

110.12 is hardly enforceable

 

[Aaro]

Do you have photos?



I don't really understand the layout here. Is the concern the conduit/wiring method? Or a outlet box? Or some other type of box?

The box is sticking out and not flush? Or the box is flush but improperly secured?

ABB SITE for the SSF-SH2346 product used

This is the ABB site that now owns T&B. This product depends on something to push up against to stabilize it. Because there is no sheetrock on the other side of the studded wall, it pushes back. A mud ring and 4X4 box are mounted to this product.

 

[Aaro]

Sounds like they are using something similar to Caddy C23 and will probably be fine but you can suggest that they use TSGB's

110.12 is hardly enforceable

This is true. Kind of like we have the right to a speedy trial.

 

[Elect117]

I tried to download the install instructions for that product but got a 403 error. So maybe take a look and see if they installed it the way ABB said to.

Maybe you are looking for something in 314.23? Or 314 in general? I have seen some pretty janky box mounting with some office TIs but they installed it per manufacturer's instruction.

 

[infinity]

I agree with Roger. If you want to push the issue then they need to use a bracket that spans across two studs. Caddy makes many such brackets.

 

[roger]

I tried to download the install instructions for that product but got a 403 error. So maybe take a look and see if they installed it the way ABB said to.

It is a knock off of the Caddy C23

 

[Joe.B]

I think I get what you are saying. Normally metal studs will have wallboard (or similar) on both sides and that provides a lot of the structure to the stud. Without being secured on both sides the metal stud will have a lot of movement and flexibility. If the box is secured to one stud only, it will also have a lot of movement and I think that would be very problematic.

You may have a difficult time enforcing this if you're only referencing the NEC. You will probably need to dig in and find the standard for design being used, if any. If you're lucky there will be a good set of plans and they will reference a design standard for the cold-formed steel framing. If this is just getting thrown together without any planning or consideration then you could be in for a tough fight.

Do you know if there are good plans the outside contractor is working from? Is there an Architect or Engineer involved? If not you may get some traction by pointing that out and use something like what @infinity or @roger are suggesting. If the choice is "do a better job" or "get an Engineer/Architect involved" they will almost always try to make it right in the field.

If the project falls under some version of IBC then look at section 2211 Cold-formed Steel Light-frame construction. They reference AISI S240, I've never looked at that, but it may provide the standards you need.

 

[Little Bill]

I think I get what you are saying. Normally metal studs will have wallboard (or similar) on both sides and that provides a lot of the structure to the stud. Without being secured on both sides the metal stud will have a lot of movement and flexibility. If the box is secured to one stud only, it will also have a lot of movement and I think that would be very problematic.

This is not what he is talking about. The bracket has tabs in the back that would meet with drywall on the other side of the wall. This would prevent the box from pushing in when something is being plugged in. In this case, there is no drywall on the back side, so nothing to prevent the box from pushing back.

 

[Joe.B]

Got it, that makes sense. Still probably something that's going to be hard to enforce out of the NEC alone right? I'm hoping he's got plans to reference. They probably won't have this detailed out, but they would at least reference a standard that he could look to for some citation. Hard to enforce anything without a specific citation... Or maybe the box they're installing will have a UL or ASTM listing that will provide install guidelines?

 

[roger]

Many of the specs I had for jobs called for boxes to be supported from two studs, the TSGB's I mentioned accomplished that.

 

[Joe.B]

Or maybe just this?

300.11 Securing and Supporting
(A) Secured in place. Raceways, cable assemblies, boxes, cabinets, and fittings shall be securely fastened in place.

 

[Joe.B]

Many of the specs I had for jobs called for boxes to be supported from two studs, the TSGB's I mentioned accomplished that.

Yeah, I've always seen them installed that way. Never had to look for a code citation to back it because it was already that way...

 

[Eddie702]

I have the same problem with plastic boxes. I bought some 2 gang Carlon's with the side bracket that has a bunch of holes in the bracket you screw into the edge of the stud (not the 3 1/2" face) but the end farthest from the stud is a bit floppy. I used these on old work and chopped out the sheetrock to screw it to the stud.

One of them was on an outside wall so I put a screw through the back of the box into the sheathing and that worked well. The other box I couldn't do that as it was sheetrock on the other wall. I patched the hole up with patching compound around the box and that did help a little

 

[augie47]

I've encountered that before on existing jobs. I used Arlington extension rings and the "lip" helped secure the devices.
If I was in a position to do so I would not accept the work as presently installed

 

[infinity]

In this case, there is no drywall on the back side, so nothing to prevent the box from pushing back.

View attachment 2571798

If you only had to install a few boxes in the one side sheetrocked wall you could simply mount your own strip of rock or pice of stud on the backside to stop the box from going backwards. As with most things if you have many boxes to install it's just faster and cheaper to use the proper bracket.

 

[electrofelon]

I think attaching a box with a side bracket to one stud without those back support brackets is kinda hack. I wouldn't be opposed to the NEC specifically calling that out as unacceptable.

 

[Little Bill]

If you only had to install a few boxes in the one side sheetrocked wall you could simply mount your own strip of rock or pice of stud on the backside to stop the box from going backwards. As with most things if you have many boxes to install it's just faster and cheaper to use the proper bracket.

I think the OP had a wall added to avoid columns. In that case there would be no access to the back side to add anything. He would have had to do it before the drywall went up.

 

[electrofelon]

One fix might to drill and tap a hole in the box and run a piece of threaded rod in until it hits something