Quite how this relates to normal use is a bit obscure
I agree. From what little I've read from that standard I get the impression that it's more trying to control the temperature rise of the terminals from heat generated by the MCB itself (e.g. from the thermal element as well as it internal conductive parts), rather than deal with heat from the connected conductor - although clearly each is going to influence the other.
Quite how this relates to normal use is a bit obscure
I agree. From what little I've read from that standard I get the impression that it's more trying to control the temperature rise of the terminals from heat generated by the MCB itself (e.g. from the thermal element as well as it internal conductive parts), rather than deal with heat from the connected conductor - although clearly each is going to influence the other.
