# 300.4(g) protection against physical damage



## Awg-Dawg (Jan 23, 2007)

jimk7525 said:


> According to 300.4(g) if you are working with 4 awg or larger you need a bushing. Can't seem to find anything else, and wondering if i am missing something about groups of wire, say 20 #12's in a 1" emt. Thanks




RMC is one instance. *
344.46 


I don't know of anything that would required a bushing on the EMT in your case.





*


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## wildleg (Apr 12, 2009)

be sure to check the job specs


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## SdCountySparky (Aug 6, 2014)

Just buy EMT insulated throat connectors.


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## Carultch (May 14, 2013)

jimk7525 said:


> According to 300.4(g) if you are working with 4 awg or larger you need a bushing. Can't seem to find anything else, and wondering if i am missing something about groups of wire, say 20 #12's in a 1" emt. Thanks


Looking for NEC exceptions to the bushing requirement is asking for trouble. Sure the NEC might allow you to omit the bushing, but that doesn't necessarily mean you should omit it. Remember, the NEC is only the minimum standard.

You need to visualize that insulation being dragged and worn against the sharp edges of threaded fittings. That insulation is there to keep current insde the wire where it belongs. You do not want to damage it, from the process of pulling the wire.

Put a bushing everywhere you can, unless equivalent protection (e.g. a box with female thread entries, or a Myers hub) can be achieved.


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## jimk7525 (Dec 12, 2012)

Carultch said:


> Looking for NEC exceptions to the bushing requirement is asking for trouble. Sure the NEC might allow you to omit the bushing, but that doesn't necessarily mean you should omit it. Remember, the NEC is only the minimum standard.
> 
> You need to visualize that insulation being dragged and worn against the sharp edges of threaded fittings. That insulation is there to keep current insde the wire where it belongs. You do not want to damage it, from the process of pulling the wire.
> 
> Put a bushing everywhere you can, unless equivalent protection (e.g. a box with female thread entries, or a Myers hub) can be achieved.


I use bushings 90% of the time, knowing that of what you wrote. It was a hypothetical situation, but seeing if i missed something some place in the NEC when the topic of bushings came up. I wouldnt put that many #12's in a one inch, but if i did a bushing would be on the list.


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## Magoo5150 (Mar 1, 2007)

Since EMT can not be threaded, the only bushing rule that applies is for 4 AWG and larger. All EMT raceways must be made up with fittings and can not enter a box or device directly. On the other hand, for the cost of a bushing, why take the chance on damaging conductors? Slap it on there and let it roll.


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## RIVETER (Sep 26, 2009)

jimk7525 said:


> According to 300.4(g) if you are working with 4 awg or larger you need a bushing. Can't seem to find anything else, and wondering if i am missing something about groups of wire, say 20 #12's in a 1" emt. Thanks


Common sense should prevail. If you are a qualified electrician someone else does not need to tell you the the insulation on your conductors in a particular instance is excessive.


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## aftershockews (Dec 22, 2012)

RIVETER said:


> Common sense should prevail. If you are a qualified electrician someone else does not need to tell you the the insulation on your conductors in a particular instance is excessive.


Here they require a bushing on any male connector 3/4" or larger no matter what size wire is pulled.


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