The Elta 149-ACO3/BDV auto changeover panel is a versatile controller designed for use with AC and EC single or three-phase twin fans. It ensures continuous operation by automatically switching between run and standby fans in the event of a failure. This panel includes a duty share option for balanced fan usage, remote enable capability for external system control, and a VFC fail contact for fault indication. It provides a reliable solution for fan redundancy and efficient ventilation system management.