Automatic transfer switch for home generator, generator automatic transfer switch, or generator switch box
An automatic transfer switch or home generator switch transfer works by continually monitoring the incoming mains supply. If the voltage of the mains supply fails or is significantly reduced to create a brownout condition, it will immediately disconnect the mains supply and command the Generator to start.
Once the automatic transfer switch has started your generator and is producing a stable supply it will transfer the load to the Generator.
When a stable mains supply is restored it will carry out the reverse process, transferring the load back to the mains and shutting down the generator hence the name automatic transfer switch.