How Does an Automatic Transfer Switch Work

An automatic transfer switch typically uses a microprocessor to continuously monitor electrical signals. It measures parameters like voltage and frequency to ensure that the incoming supply is stable and adequate to power the circuit downstream.

It connects by default to a primary power source. However, as soon as this supply fails, it will automatically switch to the alternate. It’s also possible to manually revert to the backup supply by using manual control.

Some transfer switches transfer power instantaneously, while others wait up to 30 seconds before connecting to the secondary supply. This depends on your backup source, be it a generator or an inverter.

Typically, generators require a few seconds to stabilize their output; that’s why the ATS has a time delay. But if you’re using an inverter source, the transfer is usually instant because of the inverter’s stable nature.