4、utionandautomationcontrol.Soconsistency of performance oftheACcontactorhasgreateconomicsignificance.Butfurtherdevelopmenthassofarbeenconstrainedbyitselectricallifewhichbelowthemechanicallife’slevel.Thedirecteffectonelectricallifeiselectricarcthathasproducedinswitchingprocess.Especiallyundert