The Elta 149-ACO3/B auto changeover panel provides reliable control for AC and EC single or three-phase twin fans, enabling automatic changeover in case of fan failure. It supports run and standby modes to ensure continuous operation. The panel includes a duty share option for balanced fan usage, a remote enable function for external control, and a VFC fail contact for fan fault monitoring. This controller is ideal for maintaining system reliability and efficiency in ventilation setups requiring fan redundancy.