# next size up contradiction...



## Zaped (Jul 6, 2008)

The subject here is...going to the next size up circuit breaker for branch circuits.

Can you explain/resolve the following, possible, code-related contradiction please?

( from 2008 Handbook, from the Commentary following 204.4(B), quote: )

"Section 210.19(A) requires that branch-circuit conductors have an ampacity not less than the rating of the branch circuit and not less than the maximum load to be served. These specific requirements take precedence over 240.4(B) [next 'breaker size up' sub section], which applies generally."

( in other words, the above seems to say flatly that you can never up-size a breaker to next size up for a branch circuit ).

But contrary to the above-quote commentary passage, I do not see any wording in 210.19(A) that backs up the conductor "ampacity not less than the rating of the branch circuit" ever claim.

And 204.4(B) sez you can up-size breaker to next size up. 

So, is there any language in 210.19(A) that is a total prohibition against ever going to 'next size up' breaker for branch circuits, or not ?


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## BBQ (Nov 16, 2010)

Zaped said:


> So, is there a flat prohibition in Code against going to 'next size up' breaker for branch circuits, or not ?


Only for branch circuits that supply more than 1 receptacle. 





> *210.19(A)(2) Branch Circuits with More than One Receptacle.*
> Conductors of branch circuits supplying more than one receptacle
> for cord-and-plug-connected portable loads shall
> have an ampacity of not less than the rating of the branch
> circuit.


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## wildleg (Apr 12, 2009)

you need to understand Rogers rule - it only says what it says, not what you think it said

you cannot exceed the ampacity of the conductor is what it says

240.4 tells you when you can use next size breaker, and other info. just because you are upsizing the breaker doesn't mean you are exceeding the ampacity (which is not allowed), because the load is often less than the maximum ampacity of the conductor

both articles also give you info as to when, specifically, you can use other ways to get to the conductor size and breaker size that applies, and what articles to go to for your situation


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## Zaped (Jul 6, 2008)

Wild Leg. BBQ. Thanks. I'm studying what you wrote. --Zaped


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## Zaped (Jul 6, 2008)

BTW, I don't see any NEC definition for 'cord and plug connected portable loads'. So would a table lamp be a 'cord and plug connected portable load' ? 
Toaster on kitchen counter ? 
Clock radio ?


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## wildleg (Apr 12, 2009)

Zaped said:


> BTW, I don't see any NEC definition for 'cord and plug connected portable loads'. So would a table lamp be a 'cord and plug connected portable load' ?
> Toaster on kitchen counter ?
> Clock radio ?


yep
,


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## Zaped (Jul 6, 2008)

*210.19(A) vs 240.4(B) v's commentary following 240.4(B)*



wildleg said:


> you need to understand Rogers rule - it only says what it says, not what you think it said


Wildleg. Thanks. Sometimes that happens. True.



wildleg said:


> you cannot exceed the ampacity of the conductor is what it says
> 
> 240.4 tells you when you can use next size breaker, and other info. just because you are upsizing the breaker doesn't mean you are exceeding the ampacity (which is not allowed), because the load is often less than the maximum ampacity of the conductor


Upsizing breaker to next size up doesn't mean you are exceeding the ampacity necessarily..... Ok, true. Touche.

But contrary to the claim in the Code commentary passage quoted in OP, I, reading in 210.19(A), do not see any 'blanket' (i.e., all encompasing) statement against breaker exceeding conductor ampacity for branch circuits (excepting the 'multioutlet branch circuit' case).

And 240.4(B) states, quote:

"The next higher standard overcurrent device rating (above the ampacity of the conductors being protected) shall be permitted to be used, provided all of the following conditions are met:" Yadda, yadda, yadda.

Apart from the cases where there's plenty conductor ampacity to play with, without breaker exceeding conductor ampacity, there nevertheless seems to be some rivalry between 'circuit breaker rating being above the amapacity' ( as allowed by code sub section 240.4(B) ) and the language saying "requires that branch-circuit conductors have an ampacity not less than the rating of the branch circuit" which is stated in the post 240.4(B) Code commentary in 2008 NECH quoted and cited in OP, and re-quoted below. [ I note here that: rating of the branch circuit=breaker size ].



zaped said:


> ( from 2008 Handbook, from the Commentary following 204.4(B), quote: )
> 
> "Section 210.19(A) requires that branch-circuit conductors have an ampacity not less than the rating of the branch circuit.... These specific requirements take precedence over 240.4(B) [next 'breaker size up' sub section], which applies generally."


 

I may be blowing smoke here about something that is not all that important. I don't know. I am just trying not to miss any information possibly useful down the road. 

Thanks, --Zaped


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## Roger (Jul 7, 2007)

wildleg said:


> you need to understand Rogers rule - it only says what it says, not what you think it said


Wildleg, I wish I could take credit for that but, it is actually part of "Charlie’s Rule of Technical Reading"



> *Charlie’s Rule of Technical Reading*
> 
> It doesn’t say what you think it says, nor what you remember it to have said, nor what you were told that it says, and certainly not what you want it to say, and if by chance you are its author, it doesn’t say what you intended it to say. Then what does it say? It says what it says. So if you want to know what it says, stop trying to remember what it says, and don’t ask anyone else. Go back and read it, and pay attention as though you were reading it for the first time.


 
Roger


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## wildleg (Apr 12, 2009)

lol, I couldn't remember who's rule it was. you seemed like the likely suspect, but thanks for clearing it up


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## Barjack (Mar 28, 2010)

wildleg said:


> lol, I couldn't remember who's rule it was. you seemed like the likely suspect, but thanks for clearing it up


You should have applied Charlie's Rule to Charlie's Rule. :jester:


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