The products of CXB18-63(L7)belong to the advanced level of the nineties in zhe word instead of the older generation of L7.They have protective function as shortage as overload,and are used in lighting distribution system in industy,commerce and dwelling,and protect fractional electric motors.And the also have many merits of high protective grade (upto IP20),high break capacity,reliable sensitive action,concenient,multipole assembing,long life etc.They are mainly adapted to the circuit of AC 50Hz,230Vin single pole,400Vin double,three ,four poles for protecting overload and short circuit.Meanwhile,they are also used in turning on or off the electric apparatus and lighting circuit under the normal condition.