C60N, C65N series circuit breaker belongs to the advanced level of the nineties in the world instead of the old generation of C45N. The have protective functions as shortage and overloading, and are used in lighting distribution system in industry, commerce and dwelling, and protect fractional electric motors. And they also have many merits of high protective grade (up to IP20), high breaking capacity, good reliability of sensitive action, convenient multi-pole assorting, long using life etc. They are mainly adapted to the circuit of AC 50Hz, 230V in single pole, 400V in double, three on four poles for protecting overload and shortage. Meanwhile, they are also used in turning on or off electric apparatus and lighting circuit under the normal condition.