DIN VDE 0641-21-2018 电工器件.家用过流保护断路开关及类似装置.第21部分:选择性主断路开关
Electrical accessories - Circuit-breakers for overcurrent protection for household and similar installations - Part 21: Selective main circuit-breakers
DIN VDE 0641-21 (VDE 0641-21) applies to selective main circuit-breakers (SMCBs) for operation at 50/60 Hz, having a rated voltage not exceeding 440 V (between phases), a rated current not exceeding 125 A and a rated short-circuit capacity not exceeding 50000 A.