... (or CTNR type).2.Principle of Operation: a.Turnning on the power switch,380V alternating current can become to 163V low power ... step is ready for magnet lifting .b.When we turn on the lifing switch,direct current contactor KM1,KM3 closed,transformer secondary winding ... steel plate or iron billets firmly.c.When we turn on the droping switch ,direct current contactor KM1,KM3 release,the coil of ...