Chase nipple over 250V?

[Smart $]

... For what it's worth according to the wording of 300.4(G) a chase nipple cannot be used with conductors #4 or larger since one side does not have an insulating material.

...
I agree that is what is written, I also think that wording needs changes and have a feeling the intent there is not to prohibit the use of a chase nipple - but I could be wrong. That said I have used chase nipples for conductors #4 or larger many times and have never been called out on this by an inspector. But it is no different then the earlier mentioned driving over the speed limit doesn't mean you will always get a ticket for it.

Yeah, I too think it needs reworded. A smoothly rounded surface should be permitted. Smoothly-rounded or flared-entry surfaces [non-insulating] are permitted by the exception, but that's only for integral hubs or bosses... not fittings.

 

[infinity]

There are a few proposals for the 2017 that address the smooth rounded edge issue.

 

[jap]

Seems 300.4 G could be fixed the problem with the chase nipple by simply adding an "or" between "rounded" and "insulating"

the conductors shall be protected by an identified fitting providing a smoothly rounded or insulating surface,,,,,

 

[Smart $]

Seems 300.4 G could be fixed the problem with the chase nipple by simply adding an "or" between "rounded" and "insulating"

the conductors shall be protected by an identified fitting providing a smoothly rounded or insulating surface,,,,,

Agree... but what about the title of the subsection being "Insulated Fittings". Seems like smoothly rounded without insulating just wouldn't be proper for the title...

 

[kwired]

Agree... but what about the title of the subsection being "Insulated Fittings". Seems like smoothly rounded without insulating just wouldn't be proper for the title...

That maybe is the problem - any "public input" (formerly known as proposals) would need to have a change of the title included in the inquiry.

 

[Smart $]

That maybe is the problem - any "public input" (formerly known as proposals) would need to have a change of the title included in the inquiry.

Could put it in as another or modified exception. The existing exception accomplishes that in effect, but it limits the application to integral hubs and bosses.