The GENERAC automatic transfer switch is an intregal part of the standby power system.
GENERAC transfer switches are sized according to your utility's incoming service. They range from 100 amps to 600 amps.
When the utility power is interrupted, the generator detects the problem and powers up. Just seconds later, the automatic transfer switch safely disconnects the utility line and simultaneously connects a new power line from the generator. When utility power is restored, the switch goes back to utilty mode and the generator cools down and shuts off. The system goes back to standby mode ready for the next outage.