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What is an automatic transfer switch?

An automatic transfer switch (ATS) is a PDU that provides power redundancy to IT equipment to prevent shutdowns when the primary power source fails or requires maintenance. Acting as a go-between for power sources and traditional PDUs, an ATS will automatically switch from the primary power source – either utility power or a UPS – to a secondary source, such as a UPS, in approximately 10 mili-seconds when it detects a power disturbance. Working with traditional PDUs, this means that IT equipment stays protected from damaging power fluctuations and continues operating as normal.

Similar to an ATS, a maintenance bypass is another way to build in redundancy without incurring the cost of deploying a fully redundant system.  To learn more about how to design your backup power system to avoid unnecessary shutdowns, consider these maintenance bypass installation best practices or look at the automatic transfer switch diagrams in this brochure.