Abstract: An AC transfer switch is provided for switching between a first line cord and a second line cord. The AC transfer switch is designed to be fault tolerant and ensures that continuous operating power is supplied to a load during the transfer process. The system includes a first input from a first power line cord, a second input from a second power line cord, a switch for switching an output between the first and second power line cord, wherein the switch further includes a first contactor set for selecting the first line cord and a second contactor set for selecting the second line cord, the first and second contactor sets including two contactors in series and a control circuit for controlling the switch to select between the first and second power line cords.