Product Description:

Bosch Rexroth Indramat manufactures the RD51.1-4N-022-L-NN-FW drive controller in the RD 500 Drive Controllers series. The unit converts fixed-frequency three-phase mains power into a variable output that matches the demands of asynchronous motors. In normal operation, it adjusts output frequency and voltage so the motor follows process speed demand instead of running only at line frequency. That behavior supports conveyors, pumps, and fans that need controlled acceleration, steady running speed, and reduced energy use during partial-load operation. The controller is suited to automated plants where a PLC sends reference values and the drive responds with regulated motor output.

The inverter section is rated at 22 kW, so it can continuously supply medium-size production motors without derating. It accepts a line voltage of 380 to 480 V and remains operational when the supply varies within ±10 %, which helps reduce nuisance trips on unstable grids. Incoming power must be three-phase AC, and the drive uses U/f curve control to maintain the intended magnetizing current across the motor speed range. This control method is commonly used on pump, fan, and conveyor applications where smooth speed adjustment is more important than high-performance servo response. An integrated mains filter reduces conducted emissions and limits the need for additional EMC components in the cabinet.

Thermal management is handled by forced air cooling, and airflow through the heat sink keeps semiconductor temperatures within limits during continuous heavy loads. The unit operates without a built-in brake chopper, so regenerative stopping requires an external braking solution when the application returns energy to the drive. This model is design generation 1, which places it in the first RD 500 product generation. The controller is intended for standard variable-speed motor duty and does not include additional function packages beyond its core control role. That keeps the parameter set simpler for basic motor-speed applications while keeping the hardware focused on the primary inverter function.