Mounting NEMA 3R Jbox Violation?

[Smart Solar]

We are a company that installs about 6000 single gang NEMA 3R boxes a year in an outdoor location on roofs. We work in over 70 cities and one city's AHJ inspector is stating that we cannot mount our metal j-boxes by using self-tappers with a EPDM washer since it voids the UL listing of the box by modifying it.
This seems to be inconsistent with the other 70 cities building departments since it is acceptable to them. In fact, NEC 314.15 provides for drilling weep holes in J-boxes to let moisture out which if that is the case, then that would also violate the UL.

Can anyone tell us a way , or code, to inform this inspector that it is perfectly acceptable for us to install j-boxes in this way? Thank you. The jbox is the die cast aluminum 5323-0 single gang.
UL file 195978 SA C22.2 No 18
The Self-tapping Screw with Neo0EPDM washer is type BSD = SAE J78-2013
Thanks

 

[Jraef]

110.3(B)
Must be used and installed in the manner in which it was listed (paraphrased). If the j-box mfr provides mounting ears and you are not using them, choosing instead to drill through the back, then you are violating this article.

 

[wwhitney]

FWIW, the specifications downloadable from the page below say "Eight box mounting options with detachable lugs". But I couldn't find the instructions on line to see what they actually say as far as mounting.

1-Gang Weatherproof Box, Five 1/2 in. Threaded Outlets, Gray | 5323-0 | Bell

1-Gang Weatherproof Box, Five 1/2 in. Threaded Outlets, Gray

www.hubbell.com

Cheers, Wayne

 

[infinity]

We are a company that installs about 6000 single gang NEMA 3R boxes a year in an outdoor location on roofs. We work in over 70 cities and one city's AHJ inspector is stating that we cannot mount our metal j-boxes by using self-tappers with a EPDM washer since it voids the UL listing of the box by modifying it.
This seems to be inconsistent with the other 70 cities building departments since it is acceptable to them. In fact, NEC 314.15 provides for drilling weep holes in J-boxes to let moisture out which if that is the case, then that would also violate the UL.

Can anyone tell us a way , or code, to inform this inspector that it is perfectly acceptable for us to install j-boxes in this way? Thank you. The jbox is the die cast aluminum 5323-0 single gang.
UL file 195978 SA C22.2 No 18
The Self-tapping Screw with Neo0EPDM washer is type BSD = SAE J78-2013
Thanks

The reason you never had a problem elsewhere is because this inspector is making up his own rules. Boxes can be drilled and punched as needed. Why would someone even bother to think that this is a problem with a metal box? A plastic box would be a different story.

 

[curt swartz]

That box has 2 small KO's in the back to be used for mounting with internal screws if not using the ears.

 

[Tulsa Electrician]

Note: except round

 

[Tulsa Electrician]

Also note silicone shall be used on plugs. Per there instructions.

 

[infinity]

That box has 2 small KO's in the back to be used for mounting with internal screws if not using the ears.

But what would require you to use them and not make your own holes? The KOs are provided for convenience.

 

[Smart Solar]

Thank you for the quick thoughts so far. Seems like we have differences of opinion. The boxes that we install (Bell) from Hubbell have instructions that indicate: (install lugs on box, Mount box to surface,,,etc.) We don't use the little lugs and we just drill through the side with self-tappers with combined EPDM washer. Seems like since we are not using the tabs that the inspector has got us, and we will have to reinstall the boxes using tabs in this one city out of 70.

Since the same city requires us to drill the weep holes in the bottom (which obviously would not be a step in the installation instructions from Hubbell) , this seems like a contradiction.

I have emails into Hubbell asking them for the "eight mounting methods" which I can't find anywhere either.

I'll keep you posted on new developments, and if anyone else can provide some useful content we would appreciate it.
Once I am cleared to post images I'll post them.

All the best to you all in all your endeavors,
"Saving the world by installing extra tabs... one jbox at a time....."

 

[infinity]

Thank you for the quick thoughts so far. Seems like we have differences of opinion. The boxes that we install (Bell) from Hubbell have instructions that indicate: (install lugs on box, Mount box to surface,,,etc.) We don't use the little lugs and we just drill through the side with self-tappers with combined EPDM washer. Seems like since we are not using the tabs that the inspector has got us, and we will have to reinstall the boxes using tabs in this one city out of 70.

I would ask can you drill a hole in the box and install a Myers hub? My answer is yes of course so having said that why can't you make your own mounting holes? And just for the record I have yet to see a dissenting opinion that has been able to provide a code section that prohibits drilling a hole in a metal box. There are metal boxes that come with no holes. If you can't drill them then how can you actually use them?

 

[wwhitney]

And just for the record I have yet to see a dissenting opinion that has been able to provide a code section that prohibits drilling a hole in a metal box.

The 110.3(B) based dissent (not sure I buy it) is that if the instructions provide for a list of mounting options, you must use one of those options. If drilling your own hole isn't a listed option, you're out of luck mounting wise. You can still drill holes for other purposes if not prohibited by the instructions.

Cheers, Wayne

 

[Little Bill]

Those boxes have dimples/bumps that you whack with a hammer or punch. I guess that's what is being called KOs. I usually knock them out but occasionally I drill my own holes. I never had an inspector say anything. As a matter of fact, I don't think they ever even look in there.

 

[curt swartz]

But what would require you to use them and not make your own holes? The KOs are provided for convenience.

I wasn't saying you are required to use the factory ko's. Just commenting using the mounting ears is not the only way the manufacture intends the box to be monted.

 

[Jraef]

From NFPA.org:
“Section 110.3(B) of the NEC requires that listed or labeled products be installed in accordance with any instructions included in their listing or labeling. This makes compliance with those restrictions part of the requirements of the NEC.”

Like it or not, this is what it says. But if the installation instructions mention punching out something to mount through the back, and that is what you are doing, then show those instructions to the AHJ. If however you are doing something totally not mentioned in the installation instructions, then he has a point. Other SHJs have the prerogative to accept what you are doing, but the one who is not has the NEC on his side. If you challenge him, I believe you would lose.

Why not just mount them as the instructions show?

 

[curt swartz]

From NFPA.org:
“Section 110.3(B) of the NEC requires that listed or labeled products be installed in accordance with any instructions included in their listing or labeling. This makes compliance with those restrictions part of the requirements of the NEC.”

Like it or not, this is what it says. But if the installation instructions mention punching out something to mount through the back, and that is what you are doing, then show those instructions to the AHJ. If however you are doing something totally not mentioned in the installation instructions, then he has a point. Other SHJs have the prerogative to accept what you are doing, but the one who is not has the NEC on his side. If you challenge him, I believe you would lose.

Why not just mount them as the instructions show?

All of the Nema 1 and 3R cans and gutters I purchase don't have any factory KO's. Also none of the panelboard boxes I purchase have KO's. None of them have instructions for punching KO's. I guess this equipment is useless?

 

[Jraef]

All of the Nema 1 and 3R cans and gutters I purchase don't have any factory KO's. Also none of the panelboard boxes I purchase have KO's. None of them have instructions for punching KO's. I guess this equipment is useless?

These are not “cans”, they are cast aluminum WP boxes (aka “Bell boxes”).

 

[tortuga]

Where in the code does it require a metal box to be listed?

 

[wwhitney]

Where in the code does it require a metal box to be listed?

For wet locations, 314.15.

Cheers, Wayne

 

[Smart Solar]

But what would require you to use them and not make your own holes? The KOs are provided for convenience.

I can send a pic of how we normally install them. It is much quicker and more robust the way we do it. Using the tabs costs us quit a bit more time. Most of us (Solar companies) do it our way.

 

[infinity]

I can send a pic of how we normally install them. It is much quicker and more robust the way we do it. Using the tabs costs us quit a bit more time. Most of us (Solar companies) do it our way.

The tabs are pressed in place are thin pieces of aluminum and are junk. I never use them. The ones that are held into the box with screws are slightly better.