The PowerShield Automatic Transfer Switch (ATS) is designed with two independent power inlets to supply power to the load from a primary or secondary power source. Should the primary power source fail, the secondary will automatically supply power to the connected equipment. The transfer time from one power source to the other is seamless to the connectedequipment. After switching to a secondary power source, the ATS can also switch power back to the primary input when power to the primary input is restored.