You can use the FortiGate-5053B 1U 19-inch rack mount power supply shelf with PSU-5000B hot swappable power supplies to convert AC power to DC power to supply power to a FortiGate-5000 series chassis. The FortiGate-5053B power supply shelf can include up to four PSU-5000B power supplies. The power supply shelf can be connected to high line AC input or low line AC input. The FortiGate-5053B power supply shelf edge controller controls and manages the power supplies, provides for redundancy, and provides a control and alarm communication interface for the power supply shelf. You can install extra PSU-5000B power supplies in a single FortiGate-5053B power supply shelf to provide power redundancy. If a PSU-5000B fails or is removed a backup PSU-5000B will continue to supply power.