DW45 series intelligent circuit breaker is applicable for distribution network with rated frequency of AC 50Hz, rated voltage of 400V and 690V, and rated current of 630 to 6300A to distribute electric energy protection circuit and prevent power equipment from the harm of overload, under-voltage, short circuit and single-phase earth. Provided with intelligent protecting function and precise selective protection, breaker can enhance the dependability of power supply and avoid unwanted power cut. It has functions of shunt excitation release, under-voltage release, electric operating mechanism, closed electromagnetic rated operating voltage as well as required power. The operating voltage of intelligent release is AC 380V, 220V and DC 200V, 110V. This intelligent breaker is specified into fixed type and drawer type according to installation ways. In terms of operating ways, it can be classified into motor operation and mechanical operation (for the use of examining, repairing and maintenance). In the light of poles, it can be classified into 3 poles and 4 poles. According to categories of tripper, it can be sorted with (1) intelligent type over-current controller; (2) under-voltage instant or delayed acting tripper; and (3) releasing tripper. Its intelligent type over-current controller can be classified into H for communication type, M for general intelligent type, and L for economic type. This product is in accordance with the standards of IEC947-2 and GB14048.2.