Frequency converter speed regulating circuit with three-speed setting operating box

FR-AT is a three-speed setting operating box. When the motor M requires different speeds in a certain period of time during operation, such as polishing, stirring, drying, dehydration, centrifugation, grinding, cleaning and other mechanical equipment, often multiple speeds are required in the process, then optional The circuit is shown in the figure. The three-speed selection can be controlled through three manual switches S1, S2 and S3. The connection line between FR-AT and the inverter should use shielded wire.