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Breaker Rating, Iu vs In #169143 09/27/07 06:07 AM
Joined: Mar 2005
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SteveFehr Offline OP
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I'm used to seeing either Iu or In, or the two identical, but I recently came across a molded case breaker (GE D125) that had an Iu=125A and In=100A, (adjustible from 75-100A). It's not a plug, it's built into the breaker and can't be changed beyond the pot. What, exactly, does this mean? As I understand it, Iu=125A means the contacts are rated for 125A... but with a 100A trip setting, why does that matter in the least? Why would they even bother labeling it? Am I missing something here?

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Re: Breaker Rating, Iu vs In [Re: SteveFehr] #169227 09/29/07 05:36 AM
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Scott35 Online Happy
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Could this be a 125 Amp frame, with a 100 Amp trip?

Kind of looks that way from the Spec # (GE D 125), but who knows.

Let me check the GE catalog, then reply later.

Scott


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Re: Breaker Rating, Iu vs In [Re: Scott35] #169251 09/29/07 09:46 PM
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SteveFehr Offline OP
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That's my working assumption, too, Scott. I hate guessing about things like this, though.


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