The products of PC65N belong to the advanced level of the nineties in the international instead of the older generation of DZ47. They have protective function as shortage as overload are used in lighting distribution system in dndusty, commerce and etc. They also have many merits of high protective grade(up to IP20), high breaking capacity, reliable sensityve action, convenient, multipole assembing, long life etc. They are mainly adapted to the circuit of AC 50Hz, 230V in single pole, 400V in doulbe, three, four poles for protecting overload and short circuit. Meanwhile, they are also used in truning on or off the electric apparatus and lighting circuit under the normal condition.