[MCCB] Ampere What is the meaning of Ampere Frame(AF) and Ampere Trip(AT) ?

Subject [MCCB] Ampere What is the meaning of Ampere Frame(AF) and Ampere Trip(AT) ?
Date     Inquiry 11    
Question What is the meaning of Ampere Frame(AF) and Ampere Trip(AT) ?          
Answer AT, a rated current, is the standard of over current trip in MCCB. AF is called maximum rated current, so the size of MCCB depends on the AF. For example, 100AF has various ATs such as 15,20,30…60,75,100AT, and the maximum current is 100A. According to the regulation of Korea Standard, AF is the case size of having maximum current rated voltage and operative equipment related with controlling function of circuit breaker such as capability for insulation, temperature increase, short circuit capacity.