Raco 257 Box Usage

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wbdvt

Senior Member
Location
Rutland, VT, USA
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Electrical Engineer, PE
Hello,
In a facility, we have boxes that are basically hanging (which is another issue) with outlets in them. See picture. A plant technician has said the boxes cannot be used for that as there are multiple knockouts in the box and that is a code issue. I have been unable to find a definitive code on that besides possibly 110.3(B), 110.12. Any other places I should look?

Thank you in advance!
 

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wbdvt said:
Hello,
In a facility, we have boxes that are basically hanging (which is another issue) with outlets in them. See picture. A plant technician has said the boxes cannot be used for that as there are multiple knockouts in the box and that is a code issue. I have been unable to find a definitive code on that besides possibly 110.3(B), 110.12. Any other places I should look?

Thank you in advance!
Click to expand...

I don't think the multiple KO's is the issue, although I do think there's something about the strain relief being installed in a threaded hub or designed for pendant use somewhere.

JAP>
 
jap said:
I don't think the multiple KO's is the issue, although I do think there's something about the strain relief being installed in a threaded hub or designed for pendant use somewhere.

JAP>
Click to expand...

The tech guy was partially correct

(H) Pendant Boxes. An enclosure supported by a pendant
shall comply with 314.23(H)(1) or (H)(2).
(1) Flexible Cord. A box shall be supported from a multiconductor
cord or cable in an approved manner that protects
the conductors against strain, such as a strain-relief
connector threaded into a box with a hub.
Click to expand...
 
gadfly56 said:
Since the tech guy's complaint was only about the knockouts I don't see how you get there. It was the OP who made the observation regarding strain relief.
Click to expand...

My reply was to Jap pointing out the requirements for threaded hub. The tech guy was saying the boxes couldn't be used for hanging pendants but he had the wrong reason. OP wanted a code section and that's what I posted.
 
314.23 (1) is the rule I was looking for, although, I think it is poorly written.

When you put a phrase in a rule that mentions "such as", to me, it leaves a lot of room for interpretation.

It does not say that the strain relief "must" be threaded into a hub.

It' seems to be giving only 1 example of how to keep the strain off of the cord.

JAP>
 
Thanks all. I don't think this box qualifies as a pendant as it has 2 duplex outlets in it. To me, the term pendant brings to mind a yellow handheld box that contains pushbuttons for equipment such as a crane.

In this case, since there is no issue with KO's I think it should be firmly attached per 314.23.
 
But part H is part of 314.23 and allows a pendant drop.

The box can be supported by the cord in an approved manner that "Protects the conductors against strain".

There is nothing in the box itself that does that.

The protection from strain is from the strain relief device itself and how it's connected to the box, not the box itself.



JAP>
 
JFletcher said:
the other issue I see is all of the exposed holes in the box for screws... I am pretty sure that exposed boxes like this cannot have those.
Click to expand...

Why not?

Are they any different than holes in the back or bottom of a panel or disconnect that may be mounted on a unistrut stand or a wooden post ?

JAP>
 
jap said:
Why not?

Are they any different than holes in the back or bottom of a panel or disconnect that may be mounted on a unistrut stand or a wooden post ?

JAP>
Click to expand...

Panels and disconnects are usually mounted to walls, and there is no chance of putting a foreign object either accidentally or deliberately through the mounting holes. The type of box pictured in that installation I believe violates one or more sections of the NEC, possibly 314.72 C... normally such a box is surface mounted or enclosed in a wall, where the holes in the back side are either covered or inaccessible... putting such a box on a pendant drop leaves the possibility, however remote, of one inserting a foreign object into a live electrical box... Almost the same as leaving a cover plate off of a box
 
JFletcher said:
Panels and disconnects are usually mounted to walls, and there is no chance of putting a foreign object either accidentally or deliberately through the mounting holes. The type of box pictured in that installation I believe violates one or more sections of the NEC, possibly 314.72 C... normally such a box is surface mounted or enclosed in a wall, where the holes in the back side are either covered or inaccessible... putting such a box on a pendant drop leaves the possibility, however remote, of one inserting a foreign object into a live electrical box... Almost the same as leaving a cover plate off of a box
Click to expand...

Simply not true.

Any 4 square box you buy has more holes in it than just the mounting holes in the back, and, depending on what you mount it to, you will never cover of the holes in it unless you intentionally go back and fill them all in.

JAP>
 
Even a 4 square blank cover does not make a 4 square box completely enclosed.

JAP>
 
Pretty sure's and have heard's do not belong in code conversations. It either meets code or it doesn't. I cannot tell when a picture is
rotated or it is blurry and small. Here is a picture of an owl perched on well,,, a perch. You do not need to stare long or turn your
neck to make out what the animal in the picture is. Contrast
 
I can't provide you a numeric reference but I can tell you I failed an OSHA inspection for a identical install and the OSHA rep's statement was both "hub needed and no knockouts allowed"
 
augie47 said:
I can't provide you a numeric reference but I can tell you I failed an OSHA inspection for a identical install and the OSHA rep's statement was both "hub needed and no knockouts allowed"
Click to expand...

I would need the numerical reference, otherwise, surface mount 4 square boxes of any sort shouldn't be allowed.

JAP>
 
The rule doesn't say a hub is required,and, most all electrical enclosures have knockouts in them.


JAP>
 
macmikeman said:
Pretty sure's and have heard's do not belong in code conversations. It either meets code or it doesn't. I cannot tell when a picture is
rotated or it is blurry and small. Here is a picture of an owl perched on well,,, a perch. You do not need to stare long or turn your
neck to make out what the animal in the picture is. Contrast
Click to expand...

So tell me.

Where in the code does it say that a pendant box cannot have any KO's in it or that it has to have a threaded hub?

JAP>
 
jap said:
So tell me.

Where in the code does it say that a pendant box cannot have any KO's in it or that it has to have a threaded hub?

JAP>
Click to expand...

It's an OSHA thing.

https://www.osha.gov/laws-regs/standardinterpretations/1992-06-17


"The cord set must meet all applicable requirements of 1910 Subpart S and 1926 Subpart K. For example, the assembly must be marked appropriately (1910.303(e)) and (1926.405(g)(2)(iv)); boxing intended for use in a permanent installation may not be used (1910.303(b)(1)(i) and 1926.403(b)(1)(i)); cords must be connected to devices and fittings so as to provide strain relief (1910.305(g)(2) (iii) and 1926.405(g)(2)(iv)); cords passing through holes in enclosures must be protected by bushings or fittings designed for the purpose (1926.405(g)(2)(v) – fittings designed to fasten cables to metal boxes are not acceptable); and no grounded conductor shall be attached to any terminal or lead so as to reverse designated polarity (1910.304(a)(2)) and (1926.404(a)(2))."
 
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