NW08H1 energy let through

[DianaEka]

I want to determine cable sizing for my switchboard and for incoming feeder I use ACB masterpack NW08H1, how to determine CB let through energy i2t for my breaker?

[Christian_Bach · Accepted solution]

Hi @DianaEka ,

Normally your max SC current should be below the H1 SC performance.

The NW08H1 being a pure "selective" ACB breaker, there will be no limitation, so the energy let-through is purely depending on your source SC capacity.

Usually a busbar is sized as per Icw performance at the max i²t value.

Does it answer your question ?

Christian