Sizing a Circuit Breaker
Sizing a Circuit Breaker
(OP)
What is the proper way to size a circuit breaker?
I have a squirrel cage motor with "X" full load amps. Does code say you will protect motors of this type...and perhaps between a certain horsepower...with a Circuit Breaker rated at "Y%" of the FLA? Thanks.
I have a squirrel cage motor with "X" full load amps. Does code say you will protect motors of this type...and perhaps between a certain horsepower...with a Circuit Breaker rated at "Y%" of the FLA? Thanks.





RE: Sizing a Circuit Breaker
RE: Sizing a Circuit Breaker
But if I may, sspear's point is still valid in a general sense. There are going to be local code related rules to sizing circuit breakers for motor circuits, you should really consult an Electrical Engineer with experience in your part of the world if you don't know this. If you are an EE and you don't know something this basic, you are in need of further training. I'm not trying to be condescending, but this is not a DIY forum, it is for Engineers and you identified yourself as an EE. But you are asking a question that should have been covered in EE-101 so I am assuming you are either not really an EE or you are an "EE/Computer Science" major and in need of additional exposure to power engineering...
"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
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RE: Sizing a Circuit Breaker
What's the difference? I've worked with two EE/Comp Sci majors who didn't know much more than an apprentice level electrician. Is there really that big of a disconnect between a stand alone EE and the comp sci alternative?
RE: Sizing a Circuit Breaker
RE: Sizing a Circuit Breaker
I'm just sayin...
"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
— Kilgore Trout (via Kurt Vonnegut)
For the best use of Eng-Tips, please click here -> FAQ731-376: Eng-Tips.com Forum Policies
RE: Sizing a Circuit Breaker
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If we learn from our mistakes I'm getting a great education!
RE: Sizing a Circuit Breaker
"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
— Kilgore Trout (via Kurt Vonnegut)
For the best use of Eng-Tips, please click here -> FAQ731-376: Eng-Tips.com Forum Policies
RE: Sizing a Circuit Breaker
I suggest you look around the site, perhaps take a look here:
thread248-288260: Motor circuit protection
Post back here if you have more specific questions. Perhaps it would be valuable to give very specific information about an example motor and supply system as a starting point, clarify which country (I assume code means NEC, but....).
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(2B)+(2B)' ?
RE: Sizing a Circuit Breaker