ATS (Automatic Transfer Switch)

In data centers, uninterrupted power is vitally important. To achieve this, an automatic transfer switch (ATS) is used to automatically transfer power from its primary source to a backup source when it senses a failure or outage. When a failure occurs in a primary power system, the ATS turns to a standby power source, such as an uninterruptable power supply. An ATS can also start up more long-term backup power systems, such as local diesel generators, to run electric equipment until utility power is restored.

Since the ATS is connected to both primary and backup power sources, it serves as an intermediary between equipment and the power supplies, acting as an electrical relay. An ATS can also act as a redundant, rack-mounted power supply for equipment that is connected to a power source with only one cord.