Leakage circuit breaker (RCBO) is mainly used in the system with rated frequency of AC 50Hz, rated voltage up to 400V and rated current up to 50A to provide leakage and overload protection. It is applicable to office buildings and dwelling houses. Its rated residualnon-action current is 15, 25, 50 and 150 respectively. The rated residual making-breaking capacity is 3,000A. Pole number is from 1 pole up to 4 poles. This product meets the standards of IEC690091 and GB16917.1.