The purpose of an Automatic Transfer Switch (ATS) is to transfer electrical power between two sources, typically a building’s primary utility source and secondary backup power source. The ATS is also utilized in other electricity switching applications including “utility to utility” (two independent public utility power sources), “generator to generator” (two or more standby electrical power sources), and “three-source systems” (two independent utility power sources + a standby electrical power source).
Download the rest of the article in PDF format – Automatic Transfer Switch (ATS) – Concepts & Applications