Under the 2011 NEC, there was a change (new section) at 110.24(B) that requires the service entrance maximum available fault current to be checked if something changes that effects this. So lets say a system was designed for 39kA available at the service with twenty 10kA branch panels. Down the road, there is a service upgrade and the new available fault current is around 68kA. At this new kA rating, the 20 branch panels now may no longer be acceptable.
Based on the new code section, it appears only the service panel needs to be checked and updated. It does not say anything about downstream panels. Is my understanding correct in that distribution equipment other than the service panel does not need checked?
Secondly, if under the 2008 NEC, there was no requirement for the AIC to be checked. So lets say there was a building addition and the utility changed their transformer and a service entrance main breaker was changed. The service panel bussing was still adequate. The AIC would not need checked, is this correct?
There are service changes all the time and it does seem impractical to have a service upgrade require all the branch panels to be checked and possibly changed out so it looks like the code is addressing this by just requiring the service panel to be checked.
Based on the new code section, it appears only the service panel needs to be checked and updated. It does not say anything about downstream panels. Is my understanding correct in that distribution equipment other than the service panel does not need checked?
Secondly, if under the 2008 NEC, there was no requirement for the AIC to be checked. So lets say there was a building addition and the utility changed their transformer and a service entrance main breaker was changed. The service panel bussing was still adequate. The AIC would not need checked, is this correct?
There are service changes all the time and it does seem impractical to have a service upgrade require all the branch panels to be checked and possibly changed out so it looks like the code is addressing this by just requiring the service panel to be checked.