# FLC and Breaker Size



## janagyjr (Feb 7, 2011)

Okay, so after working out the FLC (well, I just cheated and looked them up on the Motor FLC table in Article 430). My question is pretty simple and straight-forward, but I just want to double-check. 

Since my FLC doesn't come out to a standard breaker size, I can either size it to the next one up from it's rating (e.g. if one motor was 21A FLC go to 30A, etc. with proper wire size) or if I can get a 21A breaker, use it. In either case, though, I'd have to use 10AWG wire since, even with motors, I could only take the wire to 100% FLC if it's a dedicated circuit (which it is). 

I ask because I'm bidding a job doing the electrical for a pool company and if those goes well (and the price is right) I could see more work from them immediately.


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## HARRY304E (Sep 15, 2010)

janagyjr said:


> Okay, so after working out the FLC (well, I just cheated and looked them up on the Motor FLC table in Article 430). My question is pretty simple and straight-forward, but I just want to double-check.
> 
> Since my FLC doesn't come out to a standard breaker size, I can either size it to the next one up from it's rating (e.g. if one motor was 21A FLC go to 30A, etc. with proper wire size) or if I can get a 21A breaker, use it. In either case, though, I'd have to use 10AWG wire since, even with motors, I could only take the wire to 100% FLC if it's a dedicated circuit (which it is).
> 
> I ask because I'm bidding a job doing the electrical for a pool company and if those goes well (and the price is right) I could see more work from them immediately.


A 30 amp breaker is what you want.

A 21 amp breaker would be special order if they even do that and it will cost good money..


Good to see you again..:thumbsup:


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## don_resqcapt19 (Jul 18, 2010)

If the table in 430 shows a full load current of 21 amps, the code would permit you to use a 60 amp breaker with #12 wire (#10 if it is NM). The code would not prohibit the use of a 30 amp breaker, but it might trip on start up current.


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## janagyjr (Feb 7, 2011)

HARRY304E said:


> A 30 amp breaker is what you want.
> 
> A 21 amp breaker would be special order if they even do that and it will cost good money..
> 
> ...


Thanks and thanks. Honestly I wanted to brag about all the work that's literally dropping in my lap. 

How ya doing Harry?



don_resqcapt19 said:


> If the table in 430 shows a full load current of 21 amps, the code would permit you to use a 60 amp breaker with #12 wire (#10 if it is NM). The code would not prohibit the use of a 30 amp breaker, but it might trip on start up current.


Thanks for the response.


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## Dylanewilliams (May 17, 2013)

What is the article that allows you to use a larger OCPD than allowed in 310.16 or 240.4D? I see residential AC companies put #10 on a 40A breaker all the time, but I always thought that was not up to code.


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## SteveBayshore (Apr 7, 2013)

Dylanewilliams said:


> What is the article that allows you to use a larger OCPD than allowed in 310.16 or 240.4D? I see residential AC companies put #10 on a 40A breaker all the time, but I always thought that was not up to code.


Motors, article 430. Also check out welders, 630; overcurrent set at 200% of conductor ampacity!!


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## bkmichael65 (Mar 25, 2013)

Dylanewilliams said:


> What is the article that allows you to use a larger OCPD than allowed in 310.16 or 240.4D? I see residential AC companies put #10 on a 40A breaker all the time, but I always thought that was not up to code.


440.22 for air conditioning equipment


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## Shockdoc (Mar 4, 2010)

25 amp breaker


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## SteveBayshore (Apr 7, 2013)

Shockdoc said:


> 25 amp breaker


Motor conductor size MUST be calculated by HP listed in 430.250(+-), not FLA on nameplate. Overcurrent protection for that conductor can be up to 250% of FLC, 430.52. Can be up to 400% for hard starting equipment with a load 100 amps or less and up to 300% for loads over 100 amps. 
Motors of 1HP and larger require overload protection (motor starter or internal thermal protection).


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## janagyjr (Feb 7, 2011)

Thanks for all the replies. I was figuring my numbers right, then. Too bad I didn't get the bid. ):


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## SteveBayshore (Apr 7, 2013)

Can't win them all.


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