buckwheat
Member
- Location
- Pennsylvania
I am unable to find how many extension rings are allowed on a 4 inch sq. box. I have looked through art.370 and was unable to find anything. Should be and state only one I would hope.
Extension boxes
- Thread starter buckwheat
- Start date
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luke warmwater
Senior Member
Re: Extension boxes
There was a discussion about this not long ago on the Old Forum, but I couldn't find it in the Archives. The consensus was that there was no limit. There could be ump-teen(an industry standard term, I think)
There was a discussion about this not long ago on the Old Forum, but I couldn't find it in the Archives. The consensus was that there was no limit. There could be ump-teen(an industry standard term, I think)
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Extension boxes
This is all that I could find that would apply.
and it looks like a AHJ could take the text literly to say that it says they can only be mounted to a flush mounted box and that it does not say to another extention?
314.22 Exposed Surface Extensions.
Surface extensions from a flush-mounted box shall be made by mounting and mechanically securing an extension ring over the flush box . Equipment grounding and bonding shall be in accordance with Article 250.
Exception: A surface extension shall be permitted to be made from the cover of a flush-mounted box where the cover is designed so it is unlikely to fall off or be removed if its securing means becomes loose. The wiring method shall be flexible for a length sufficient to permit removal of the cover and provide access to the box interior, and arranged so that any bonding or grounding continuity is independent of the connection between the box and cover.
This is all that I could find that would apply.
and it looks like a AHJ could take the text literly to say that it says they can only be mounted to a flush mounted box and that it does not say to another extention?
314.22 Exposed Surface Extensions.
Surface extensions from a flush-mounted box shall be made by mounting and mechanically securing an extension ring over the flush box . Equipment grounding and bonding shall be in accordance with Article 250.
Exception: A surface extension shall be permitted to be made from the cover of a flush-mounted box where the cover is designed so it is unlikely to fall off or be removed if its securing means becomes loose. The wiring method shall be flexible for a length sufficient to permit removal of the cover and provide access to the box interior, and arranged so that any bonding or grounding continuity is independent of the connection between the box and cover.
paul
Senior Member
- Location
- Snohomish, WA
Re: Extension boxes
I guess the part where it says: provide access to the box interior would be your limiting factor.
I guess the part where it says: provide access to the box interior would be your limiting factor.
buckwheat
Member
- Location
- Pennsylvania
Re: Extension boxes
Thanks Guys
I was hoping it was not that way.
Thanks Guys
I was hoping it was not that way.
- Location
- Illinois
- Occupation
- retired electrician
Re: Extension boxes
Hurk,
That section would only apply where the original box was flush mounted. What if the original is surface mounted?
Remember that no matter how many extensions that are installed you still have to comply with 300.14 and this will require a minimum of 3" of wire beyond the last exension ring.
Don
Hurk,
That section would only apply where the original box was flush mounted. What if the original is surface mounted?
Remember that no matter how many extensions that are installed you still have to comply with 300.14 and this will require a minimum of 3" of wire beyond the last exension ring.
Don
electricmanscott
Senior Member
- Location
- Boston, MA
Re: Extension boxes
I wonder how many extensions were looking to install here and why?
I wonder how many extensions were looking to install here and why?
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Extension boxes
The way I stated the answer was to let buckwheat know that a AHJ might try to argue the wording of 314.22 to limit the amount of extension's but as we can see in 314.16 the wording extension rings is plural not singler. so it would presume that the nec's intent would be that more than one is allowed. It is little things like an S on the end of a word that can change the whole meaning of what is being said.
314.16
(A) Box Volume Calculations. The volume of a wiring enclosure (box) shall be the total volume of the assembled sections, and, where used, the space provided by plaster rings, domed covers, extension rings, and so forth, that are marked with their volume or are made from boxes the dimensions of which are listed in Table 314.16(A).
The way I stated the answer was to let buckwheat know that a AHJ might try to argue the wording of 314.22 to limit the amount of extension's but as we can see in 314.16 the wording extension rings is plural not singler. so it would presume that the nec's intent would be that more than one is allowed. It is little things like an S on the end of a word that can change the whole meaning of what is being said.
314.16
(A) Box Volume Calculations. The volume of a wiring enclosure (box) shall be the total volume of the assembled sections, and, where used, the space provided by plaster rings, domed covers, extension rings, and so forth, that are marked with their volume or are made from boxes the dimensions of which are listed in Table 314.16(A).
buckwheat
Member
- Location
- Pennsylvania
Re: Extension boxes
electricmanscott
The reason I asked this was I had to work in a box that had two rings installed. The second ring had a conduit installed in it. This made it very hard to see what circuits were in the first box. Taking the ring off I would have had to also move conduit and wire in second ring. PS it just made me mad. I would like to have said it was illegal.
electricmanscott
The reason I asked this was I had to work in a box that had two rings installed. The second ring had a conduit installed in it. This made it very hard to see what circuits were in the first box. Taking the ring off I would have had to also move conduit and wire in second ring. PS it just made me mad. I would like to have said it was illegal.
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