# Is AIC Rating the same as AIR?



## The_Modifier (Oct 24, 2009)

Yes it is. 

Both Stand for Available Inrush Current


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## erics37 (May 7, 2009)

The_Modifier said:


> Yes it is.
> 
> Both Stand for Available Inrush Current


:001_huh:

Hopefully you're not having 22,000 inrush amps on things. Pretty sure it means Ampere Interrupting Capacity/Rating. Not sure if the terms are synonymous but I would bet they are. It's how much current a device is designed to safely clear in the event of a fault.


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## The_Modifier (Oct 24, 2009)

Yuppers they are. Terms used are depending on the manufacturer


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## gv703 (Jan 27, 2013)

Thank you all for your responses. Now if I may add to this, the main reason I'm asking this is because I'm looking for a 70A 3p breaker (among others), and square d has an EDB 480/277 breaker with a rating of 18k, but in the description it states that it's rated higer (25k) for 120 & 240v. I should be able to use this for the system I stated on my orignial post, right? The price for a breaker with a 35k rating (an EGB) is $1300 more than the EDB , so I would hope to be able to use the latter. Thanks again.


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## Big John (May 23, 2010)

AIC changes depending on the voltage involved because voltage plays a large part in maintaining an arc within the breaker.

A lower voltage means the arc will be extinguished more quickly, which means that the amount of current allowed to flow through the arc is higher, because it's still less overall power that the breaker has to tolerate.

Many breakers are rated at multiple voltages, with an AIC that increases as the voltage drops. As long as the breaker is rated for your system voltage, and the available fault current doesn't exceed the AIC or series rating, you're good.


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## 99cents (Aug 20, 2012)

The_Modifier said:


> Yes it is.
> 
> Both Stand for Available Inrush Current


It has nothing to do with inrush. 

Amps Interrupting Rating - The maximum current the device can safely interrupt 

Amps Interrupting Capacity - The maximum current a device can safely interrupt at rated voltage


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## erics37 (May 7, 2009)

99cents said:


> It has nothing to do with inrush.
> 
> Amps Interrupting Rating - The maximum current the device can safely interrupt
> 
> Amps Interrupting Capacity - The maximum current a device can safely interrupt at rated voltage


Thank you for clarifying the difference :thumbup:


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## gv703 (Jan 27, 2013)

99cents said:


> It has nothing to do with inrush.
> 
> Amps Interrupting Rating - The maximum current the device can safely interrupt
> 
> Amps Interrupting Capacity - The maximum current a device can safely interrupt at rated voltage


Thanks for clarifying that. Now just to be certain, they still could be interpreted to be the same, right? Providing they're rated for the same voltage, right?


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## 99cents (Aug 20, 2012)

double post...


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## 99cents (Aug 20, 2012)

gv703 said:


> Thanks for clarifying that. Now just to be certain, they still could be interpreted to be the same, right? Providing they're rated for the same voltage, right?


I believe so. I was raised on fuses so AIR is a more familiar term to me. I THINK that AIC is a term used more with circuit breakers and that's where the "rated voltage" comes into play. Big John seems to have explained that part very well.


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## 99cents (Aug 20, 2012)

gv703 said:


> Thank you all for your responses. Now if I may add to this, the main reason I'm asking this is because I'm looking for a 70A 3p breaker (among others), and square d has an EDB 480/277 breaker with a rating of 18k, but in the description it states that it's rated higer (25k) for 120 & 240v. I should be able to use this for the system I stated on my orignial post, right? The price for a breaker with a 35k rating (an EGB) is $1300 more than the EDB , so I would hope to be able to use the latter. Thanks again.


$1300.00 MORE? You can buy three 70 amp HRC fuses for under a hundred bucks and that gives you 200K AIR. Sounds like the breaker guys have been greasing an engineer. Again.


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## Big John (May 23, 2010)

gv703 said:


> ...Now just to be certain, they still could be interpreted to be the same, right? Providing they're rated for the same voltage, right?


 For low-voltage (<1000V) breakers, they are used interchangeably. I'm quite certain of that, because I've seen it many times.

There may be a technical difference that's not related to your installation, but I don't know it. Sometime this week I'll see if I can find the honest-to-goodness definitions in the ANSI standards.


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## gv703 (Jan 27, 2013)

99cents said:


> $1300.00 MORE? You can buy three 70 amp HRC fuses for under a hundred bucks and that gives you 200K AIR. Sounds like the breaker guys have been greasing an engineer. Again.


Yeah, if I could go with fuses that'd be great! Unfortunately, the engineer calls for a square d NF panel and they only accept EDB, EDG and EJB breaker types. From the looks of it the EDBs are rated for 18k, and the EDGs for 35k. The 70A 3P EDB is ~$800, and the EDG goes for ~$2100 :excl: (the lower amp breakers aren't to far off from that either). Since the EDBs have a higher rating of 25k for 240v and below, I may go with it. I doubt the customer will oppose . In any case, that's just a quick quote I got from a local supply house, I'll have to shop around a bit...


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## mbednarik (Oct 10, 2011)

Are you buying the breakers separate from the panel? Superbreakers is at 240 es for the DB34070. Might want to talk to a better supply house.


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## gv703 (Jan 27, 2013)

mbednarik said:


> Are you buying the breakers separate from the panel? Superbreakers is at 240 es for the DB34070. Might want to talk to a better supply house.


Thanks for the tip, I'll check them out. And yeah I normally deal with a different shop, the one I got the quote from was the only one open at the time and I think they were giving me standard msrp.


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