ICU vs. ICUs of Power Circuit Breakers

Check here.

http://www.schneider-electric.com.sg/selink/sg/Schinternetnew.nsf/($All)/7BC1A412C502416C48256FBA002C1D15/$file/Vol%202.%20The%20Controversy%20of%20Icu%20and%20Ics.pdf

Dear Wareagle:

If comments in your attachment are right, what will be about the breaker having Ics: 100% of Icu?

"Icu is the current for which the prescribe conditions do not include the capability of circuit breaker to carry its rated current continuously after the test "O-t-CO". It means breaker is not able to carry its rated current without temperature rise after bearing full level short circuit.

"Ics is the current for which the prescribe conditions include the capability of circuit breaker to carry its rated current continuously after the test "O-t-CO-t-CO". It means breaker is able to carry its rated current without temperature rise after bearing full level short circuit.

Now for the breaker having 100% Ics (Ex: 600ATP, 25/25KA), what parameter will be effective i;e Icu or Ics. I mean after test breaker will be serviceable (acc to Ics) or not (acc to Icu)?

On ther other hand, I think breaker having Ics: 50% of Icu (Ex: 600ATP, 50/25KA) is better. because such a breaker will be still more serviceable after "O-t-CO-t-CO".