AIC 10 vs 22

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Ponchik

Ponchik

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Electronologist
I can't quite remember the details on how do to figure out the minimum AIC rating for a load center for a small commercial unit (specifically a small church)

The existing load center seems to be marked with 10K and am planning to replace it with a HOMELINE load center. As far as I know the HOMELINE is 10K AIC.

Edward
 
Look up the model number of the panel. The panel spec sheet should show its rating. The actual rating of the panel is determined by the smallest breaker. If the smallest breaker you have in the panel is 10kaic then the panel get slapped with a 10kaic rating, even if the spec sheet says its 65kaic.
 
WA_Sparky said:
Look up the model number of the panel. The panel spec sheet should show its rating. The actual rating of the panel is determined by the smallest breaker. If the smallest breaker you have in the panel is 10kaic then the panel get slapped with a 10kaic rating, even if the spec sheet says its 65kaic.
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OK Thank you.

The HOMELINE that I have speced is 10K rated.

If I remember correctly the AIC has to be calculated based on distance from the service, size and material of the feeder conductors... correct?

The minimum is 10K AIC unless calculated otherwise.

Edward
 
The ratings need to be based on available fault current. I don’t know the specifics on series rating homeline products.


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Busman has an app that will do the calculation, mike Holt May have a spread sheet on his website. You’ll need a label with aic for the panel
 
WA_Sparky said:
Look up the model number of the panel. The panel spec sheet should show its rating. The actual rating of the panel is determined by the smallest breaker. If the smallest breaker you have in the panel is 10kaic then the panel get slapped with a 10kaic rating, even if the spec sheet says its 65kaic.
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Sort of... The rating is based on the lowest rating in the panel, OR, on manufacturer provided TESTING of the breakers in series with each other. So you could possibly have a Main that is rated for 22kA and branches that are all rated for 10kA, but as a "SERIES LISTING", the entire setup can be used at 22kA. The panel must actually SAY THAT on the label though, you cannot do it on your own.
 
Jraef said:
Sort of... The rating is based on the lowest rating in the panel, OR, on manufacturer provided TESTING of the breakers in series with each other. So you could possibly have a Main that is rated for 22kA and branches that are all rated for 10kA, but as a "SERIES LISTING", the entire setup can be used at 22kA. The panel must actually SAY THAT on the label though, you cannot do it on your own.
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But both panels (main and the sub/s) have to be the same manufacturer, correct?
 
edward said:
But both panels (main and the sub/s) have to be the same manufacturer, correct?
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Technically that’s not a criteria but the testing costs are really high, so why would one mfr do something expensive to help sell a competitor’s products? You do however see series combinations with fuses and aside from Eaton who now owns Bussman, fuse mfrs are not the same as breaker mfrs.
 
Jraef said:
Sort of... The rating is based on the lowest rating in the panel, OR, on manufacturer provided TESTING of the breakers in series with each other. So you could possibly have a Main that is rated for 22kA and branches that are all rated for 10kA, but as a "SERIES LISTING", the entire setup can be used at 22kA. The panel must actually SAY THAT on the label though, you cannot do it on your own.
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Yes correct, i didnt go into the series rating side of things, just assumed it would be safest if they stuck to fully rated rules.
edward said:
Thank you.
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If youre curious on the series rated breakers go to the manufacturers website and try and track down a series rated breaker catalog. They will show which main breakers have been tested and approved to work with down stream breakers. Series rating basically means that if the approved main breaker and branch circuit breakers are used in combination, the branch circuit breakers rating (say 10KAIC) may now be rated for much higher. If you go with a series rated option, make sure all the breakers in the load center are still above the available fault current.
 
WA_Sparky said:
Yes correct, i didnt go into the series rating side of things, just assumed it would be safest if they stuck to fully rated rules.

If youre curious on the series rated breakers go to the manufacturers website and try and track down a series rated breaker catalog. They will show which main breakers have been tested and approved to work with down stream breakers. Series rating basically means that if the approved main breaker and branch circuit breakers are used in combination, the branch circuit breakers rating (say 10KAIC) may now be rated for much higher. If you go with a series rated option, make sure all the breakers in the load center are still above the available fault current.
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with one caveat. motor contribution can screw up everything with series rated breakers.
 
If in doubt use a main breaker panel ( negligible cost difference for those load centers anyway, MLO vs MB). Homeline main breakers are 22k and the 10k branches will series rate. I just did similar where I am installing a Siemens panel board and the AFC is about 20k, and there was no series rating with the existing upstream equipment. I could have used 22k "H" series branches as those are available with Siemens, but it is cheaper and more convenient to use a MB and the series rating.
 
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