Icu, Icw, and Integrated instantaneous Protection

[MoBawy]

Hi all,

I'm looking at NS800N Circuit breaker and I see the following technical info

Icu = 50KA / 400v

Icw = 19.2KA for 1 sec

Integrated instantaneous protection (peak) = 40KA

Now, if the peak is 40KA (which is expected, as it is 2.1*19.2), shouldn't that be a current limiting device?

Because when I look at current limiting curves, I can see that NS800N let-thru can go up to >100KA , In my mind it should peak at 40KA. 

Can someone explain what am I missing here?

Just confused how all these 3 parameters link together?

[Gregoire_Brun]

hello @MoBawy 

NS800N is not a limiter bloc, even concerning the protection curve, it include an instantaneous protection witch give an automatic trip if current exceed Ii.

Icw is a theorical value (using just for certification test) never saw by breaker on reality to demonstrate the robusness of the product.