AIC rating

[transman2]

In an electrical design with MDP's and downstream sub-panels how do you determine.

1. What AIC rating you should have for the design.

2. Should all Breakers have the same AIC rating in the MDP's and downstream Panels?

3. What code Reference supports this?

 

[cpal]

for starts
I would suggest you begin @ 110.9 and 10

for AIC, the POCO may help or you may need an engineering study.

POCO will usually only give Available Fault at the service point, down stream levels require calculations. There is software that may help also

 

[augie47]

On a properly designsed system this will have been done by an engineer using POCO input and determination other contributing factors such as motors, lengths of wire runs, etc..
In the simplest of terms, as charlie says, POCO can give you a base number either at their transformer or end of drop/lateral.
From there, you can have a "fully rated" system where all the OCP devices have the POCO number or larger rating, or you can have a "series rated" system where the gear manufacturer lists combinations of breakers/fuses that are compatible to meet the goal such as a 22k SquareD QO breaker downstream for a 65k SqaureD KA breaker, or RK5 fuses, etc.