# Table 210.21(B)3



## Dennis Alwon (May 9, 2009)

fanelle said:


> Hey guys I was just flipping through this section of my code book for some light reading and was wondering about this table. I dont understand why are you allowed to put a 50A rec. on a 40A breaker. I thought that a breaker wasn`t suposed to have more then 80% load on it. So if you have a 40A breaker and have a 40A and 50A receptical on the circuit how is that suposed to work or am I missing something.
> 
> Thanks for any light you can shead in this


Well 80% load on a breaker is not quite correct. 80% load that is continuous would be correct unless the breaker is rated 100% for continuous load. 

There is nothing in the NEC that would stop me from putting 20 amps on a 20 amp circuit unless the load is continuous.

Since no one makes a 40 amp receptacle that I know about the NEC allows a 50 amp receptacle on a 40 amp breaker. Besides how would that be an issue since if the load was over 40 the breaker would eventual trip.


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## fanelle (Nov 27, 2011)

The thing that I didn`t get is why is it acceptiable. I understand that a 50A draw would trip a 40A breaker. I did have a misunderstanding of the breaker load though. I cant really put my finger on it but something about it seems wrong but I guess that if it was the other way around you would damage your receptical before tripping the breaker.


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## fanelle (Nov 27, 2011)

Thinking about it I think I may be confusing code and workmanship. I think thats actually what it is about this that bothers me.


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