A transfer switch is an electrical switch that switches a load between two sources. An Automatic Transfer Switch (ATS) is often installed where a backup generator is located, so that the generator may provide temporary electrical power if the utility source fails.
A transfer switch is a permanent switch that connects to your power box that changes the power load between two sources (power grid and your generator).
What is the Purpose of a Transfer Switch? An automatic transfer switch (ATS) is a device that transfers a power supply from its primary source automatically to a