... 2.Vibration frequency:50-70Hz 3.Phase:three phase 4. Power type:AC AC Three-phase Surge Protector with 3 Wires1. Working ... system will be closed machine, the action is called ‘self-preservation’this will be brings great damage (such as ... Surge protective Device,Lightning Protector,Polymer Arrester,Thunder Protection,Power surge Protector,Surge Suppressor,Overvoltage Protector,Thunder Protection, ...