Automatic transfer switch for home generator
A 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.