Main Breaker kAIC Rating Justification

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JimmysLimeade

JimmysLimeade

EE Student & PV Design
Location
Utah
Occupation
PV Design
Miami Gardens is now requesting these calculations to justify the kAIC rating of a new MB when doing any service upgrade. I have made calculations according to a letter from FPL that has the available fault current at the transformer and went from there.

Do these look okay? If I get a number below 10kA, can I say that a 10kAIC rated main breaker is the minimum required and that a larger rated main breaker can be installed (like a 22kAIC rated MB)?

This seems like overkill by Miami Gardens but they require it so I have to provide it...
 

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I am a 3rd party designer for solar installers. One of my clients is requesting that we make these letters. I dont do this for any other AHJ because I dont deal with any permitting, and leave that up to the electrician to decide on the rating of the main breaker when it is needed. I just want to make sure I did this correctly before sending it to my client
 
Using Bussmann;s FC² I come up with a different number but it's still less than 10k,
 
JimmysLimeade said:
Do you have a picture? I might be missing something in my calculations
Click to expand...
I went through Bussman FC2 (hopefully I did it correctly) and came up with this:1707855667533.png

Should I be going off of the L-N ISC? My calculated L-L was 8934A which seems like a rounding error on my end compared to the 8935A calculated here.

Im not very familiar with this area so i really appreciate your patience as I learn more about it.
 
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