Weight rating 4 square boxes

[infinity]

They do make fixture swivel hangers for 1900 boxes that are rated for 50#'s so I would assume that the box is also rated for 50#'s.

https://www.cesco.com/Thomas-Betts-T-B--SH-1-2-3-4-Steel-City-SH-1-2-3-4-Swivel-Hanger/p1928367

 

[jumper]

They do make fixture swivel hangers for 1900 boxes that are rated for 50#'s so I would assume that the box is also rated for 50#'s.

https://www.cesco.com/Thomas-Betts-T-B--SH-1-2-3-4-Steel-City-SH-1-2-3-4-Swivel-Hanger/p1928367

Makes sense to me.

 

[LarryFine]

Makes sense to me.

Well, we certainly can't have that!

 

[Adamjamma]

the Carlon boxes I mentioned are 4 inch for ENT and they have various adaptors for single gang, double gang, Ceiling mud ring, etc... even have a voltage divider for the double gang if needed...
and state a weight capability of 50 pounds. On the ABB website.

But not sure of the metal boxes made elsewhere except that usually the mud rings if bought for fans state 50 lb weight limit...

It would still depend upon proper support while mounting... something I dont worry too much with as most of mine is installed before pouring concrete.

 

[jumper]

Well, we certainly can't have that!

:thumbsup:

Yep, I do better in my normal state of daily confusion.

 

[MAC702]

50# fixture and 50# fan (or even a lighter fan) are two different things. The OP didn't mentioned fans that I see, but I did when I was relaying experience of failure points.

I'm also trying to see it from an inspector's point of view, an inspector that we already know is having an issue with it, but we don't know exactly what.

 

[MAC702]

Hubble shows octagonal boxes with brackets with 50 lb. ratings.

https://www.hubbell.com/hubbell/en/...onic/Boxes/Ceiling-Boxes-Covers/119/p/1670068....

Note that a significant difference between that rated octagon bracket box and a more typical 4-S bracket box is the tabs inside the bracket that greatly assist in resisting the cantilever.

 

[hbiss]

Who said anything about a fan box?

Well, it was mentioned. In reality, if you are going to hang a large heavy fixture wouldn't you use something already designed for the load- like a fan rated box? I know that wasn't the OPs question, but why would you use a box like he is asking about for that application to begin with when a simple solution exists?

-Hal

 

[tom baker]

A device box uses 6-32 screws and can be used for a wall mount luminaire the weight limit is 6 pounds 314.27
Outlet boxes uses 8-32 screws and are rated for 50 pounds, 314.27

So a box with 8-32 is good for 50 pounds

 

[JFletcher]

They do make fixture swivel hangers for 1900 boxes that are rated for 50#'s so I would assume that the box is also rated for 50#'s.

https://www.cesco.com/Thomas-Betts-T-B--SH-1-2-3-4-Steel-City-SH-1-2-3-4-Swivel-Hanger/p1928367

it says in the product description those are for octagonal boxes, not 1900 boxes.

Edited to add... There is a square box, SHHF1234, that apparently is weight rated and for use with the swivel hanger

 

[ttjangu]

What is a bracket box? Box with a bracket/strap for mounting?

View attachment 21443

Yes, that is the style of box I am referring to and not for purposes of hanging a fan, only luminaires with a mud ring that says it is rated for 50lbs. Obviously it would be irresponsible to attach the tabs with some #6 screws or wimpy nails or staples or something. What gets me is that there is not a clear answer on this one. Seems way more stout than a cheesy carlon plastic nail on. Or, is the weight rating on the mud ring itself the part that actually matters?

 

[ttjangu]

A device box uses 6-32 screws and can be used for a wall mount luminaire the weight limit is 6 pounds 314.27
Outlet boxes uses 8-32 screws and are rated for 50 pounds, 314.27

So a box with 8-32 is good for 50 pounds

Tom, I think this is the answer. Thank you. The mud ring is attached to the box with number 8s and we always use 8s for securing the bracket.

 

[hbiss]

A device box uses 6-32 screws and can be used for a wall mount luminaire the weight limit is 6 pounds 314.27
Outlet boxes uses 8-32 screws and are rated for 50 pounds, 314.27

So a box with 8-32 is good for 50 pounds

Don't know how you reached that conclusion. I see the part about ceiling boxes having to support a maximum of 50 Lbs, I see nothing about screws.

2) Ceiling Outlets. At every outlet used exclusively for
lighting, the box shall be designed or installed so that a lu-
minaire or lampholder may be attached. Boxes shall be re-
quired to support a luminaire weighing a minimum of 23 kg
(50 lb). A luminaire that weighs more than 23 kg (50 lb)
shall be supported independently of the outlet box, unless
the outlet box is listed and marked for the maximum weight
to be supported.

The Hand Book explanation is the only place screw sizes are mentioned and that refers to wall boxes:

The exception to 314.27(A)(1) permits luminaires such as
wall-bracket types or sconces weighing less than 6 lb to be
supported by a device box using No. 6 or larger screws. De-
vice boxes designed for the mounting of snap switches,
receptacles, and other devices usually have 6-32 screws (No
6 screws with 32 threads per inch). Generally, device boxes
are not suitable for supporting other than lightweight wall-
mounted luminaires.

So my conclusion is that if a box isn't marked with a 50 Lb or more weight rating it can't be used to support a ceiling fixture. The mud ring has nothing to do with it and neither do the screws, however a box with a 50 Lb rating or better will have 8/32 or larger screws. 8/32 screws do not mean the box is 50 Lb rated though.

-Hal

 

[ttjangu]

Don't know how you reached that conclusion. I see the part about ceiling boxes having to support a maximum of 50 Lbs, I see nothing about screws.

2) Ceiling Outlets. At every outlet used exclusively for
lighting, the box shall be designed or installed so that a lu-
minaire or lampholder may be attached. Boxes shall be re-
quired to support a luminaire weighing a minimum of 23 kg
(50 lb). A luminaire that weighs more than 23 kg (50 lb)
shall be supported independently of the outlet box, unless
the outlet box is listed and marked for the maximum weight
to be supported.

The Hand Book explanation is the only place screw sizes are mentioned and that refers to wall boxes:

The exception to 314.27(A)(1) permits luminaires such as
wall-bracket types or sconces weighing less than 6 lb to be
supported by a device box using No. 6 or larger screws. De-
vice boxes designed for the mounting of snap switches,
receptacles, and other devices usually have 6-32 screws (No
6 screws with 32 threads per inch). Generally, device boxes
are not suitable for supporting other than lightweight wall-
mounted luminaires.

So my conclusion is that if a box isn't marked with a 50 Lb or more weight rating it can't be used to support a ceiling fixture. The mud ring has nothing to do with it and neither do the screws, however a box with a 50 Lb rating or better will have 8/32 or larger screws. 8/32 screws do not mean the box is 50 Lb rated though.

-Hal

Ya, I see what you mean, went back and re read 314.27 and nothing about screws. 314.23 talks about solid attachment to framing but no specifics. Back to seeking a solid answer.

 

[hbiss]

What the code is saying is that all ceiling boxes intended to support a lighting fixture has to be at least 50# rated and if the location is such that there is the possibility of someone installing a ceiling fan, the box has to be fan rated.

I'm just as guilty of this as anybody I guess. I can't tell you how many times I have done just as you describe with a 1900 bracket box and mud ring because I didn't think there would be any problem with the little ceiling fixture that weighed probably 2 pounds. Never had a problem with inspections either.

-Hal