Rated short-time withstand current Icw for time different than stated

Hello everybody.

I have several flexible copper buscar Datasheets with different Icw values for times 0.2, 0.5 and 1s.

I know it has to do with I^2t and there is a way to determine, for example, the Icw (1s) based on the Icw (0.2s) or Icw (0.5s) stated on the Datasheets.

I need to compare the different Icw values of busbar manufacturers, in order to chose the best one for my assembly.

If someone can enlighten me on the subject I will be very grateful.

I am looking forward to hearing from you.

Best regards.

Carlos Melim