Apowerrelayisanelectricaldevicethatisusedtocontroltheflowofelectricity.Itconsistsofacoilandasetofcontacts.Whenthecoilisenergized，itcreatesamagneticfieldthatcausesthecon...。...
标签： Construction
Injury Prevention in Construction: Reducing Risks and Costs
Theconstructionindustryisoneofthemosthazardousindustriesintheworld，withahighrateofworkplaceinjuriesandfatalities.Falls，struck，byobjects，electrocutions，andotheraccidents...。...