Adding additional conduit to FS Box

[MikeW]

Working in a factory and I want to add a ?? RMC to an existing FS Box. The existing box has one ?? hub that has a conduit in it. Can I drill a hole in the existing box and use a Meyers Hub to add my 3/4? conduit? Is there a NEC section I?d be violating? I have seen some other FS boxes with a hole drilled in them but have a gut feeling this is not an accepted practice. What are your thoughts? Thanks.

 

[chris kennedy]

If you can't make your own openings in boxes and enclosures why would we carry step-bits and KO sets?

 

[augie47]

Have to disagree with Chris here.
Cast Boxes, unlike "standard metal boxes", are UL listed under BGUZ. The listing states "Cast-Metal boxes suitable for field drilling and tapping of holes for conduit connections and mounting are marked to indicate the locutions and trade sizes........... "
so, although often done, it does not meet the listing unless so marked.

 

[chris kennedy]

Have to disagree with Chris here.
Cast Boxes, unlike "standard metal boxes", are UL listed under BGUZ. The listing states "Cast-Metal boxes suitable for field drilling and tapping of holes for conduit connections and mounting are marked to indicate the locutions and trade sizes........... "
so, although often done, it does not meet the listing unless so marked.

I will stand corrected until I check the white book reference given. I for one have never added an opening to a FS box as they are tight enough already. I posted without research.

 

[SEO]

Gus hit the nail on the head.

 

[LarryFine]

Mike, I guess you need to either replace the box, add one, or fit in a T-condulet.

All of these might mean the use of rigid compression fittings and/or Ericson couplings.

 

[MikeW]

One more question.

One more question.

Thanks for responses.

Another question: I see FS boxes with a single hole drilled in the back of box for a ??-20 bolt. The ??-20 bolt is used to mount box to a piece of unistrut using a spring nut. Is this an acceptable practice or a violation of code?

 

[augie47]

.................. Is this an acceptable practice or a violation of code?

somethings are both
As long as you don't alter the box, I can see no violation. Other than being "secure", I don;'t know of any Code mounting method requirements.

 

[LarryFine]

Another question: I see FS boxes with a single hole drilled in the back of box for a ?”-20 bolt. The ?”-20 bolt is used to mount box to a piece of unistrut using a spring nut. Is this an acceptable practice or a violation of code?

I'd say it's okay as long as the bolt is gasketed or sealed to maintain the box's water-tightness.

 

[ECB]

Have to disagree with Chris here.
Cast Boxes, unlike "standard metal boxes", are UL listed under BGUZ.

"All boxes in this category have a volume of more than 100 cubic inches"