Electrical box hanged by threaded rod from the ceiling slab

[Jin Kim]

Hello, fellow engineers

I encountered a box in the ceiling space that looks like the photo; wondering if it violates the code.
The closest article might be 314.23 but it doesn't state about the threaded rods.

(B) Structural Mounting. An enclosure supported from a structural member or from grade shall be rigidly supported
either directly or by using a metal, polymeric, or wood brace.

 

[Buck Parrish]

What you have pictured is a very common way to support a box. You have a 1/4 inch nut on top and below in the box. It is widely accepted every where. Unless specs call for some thing different.
For example, in a parking garage you can put a 1/2 emt sleeved over the rod and between the box and the concrete. But that's ussually only done for exposed work with a light on it.
But if it's above a drop ceiling, that box in the pic is what you get.

 

[Jin Kim]

What you have pictured is a very common way to support a box. You have a 1/4 inch nut on top and below in the box. It is widely accepted every where. Unless specs call for some thing different.
For example, in a parking garage you can put a 1/2 emt sleeved over the rod and between the box and the concrete. But that's ussually only done for exposed work with a light on it.
But if it's above a drop ceiling, that box in the pic is what you get.

Thank you Sir. for sharing your expertise and experience.

 

[LarryFine]

You have a 1/4 inch nut on top and below in the box.

It actually looks much larger than 1/4", more like 3/8". That's probably why they used the center KO.

 

[Tulsa Electrician]

Maybe use larger diameter washers if your going to knock the center ko like in picture.

 

[Ravenvalor]

Looks good for a light fixture but I would not use it to hang a ceiling fan.

 

[infinity]

I agree a common way to monitor the box at a distance below a concrete slab. As mentioned 3/8 x 1.25" fender washers would be better.

 

[jap]

Looks like a 3/8" rod.

If I personally installed the anchor in the precast, I'd feel confident skinning a deer off of it.

JAP>

 

[kwired]

Looks good for a light fixture but I would not use it to hang a ceiling fan.

Other than if it were a fan rated box, and maybe providing some sort of lateral bracing, why not?