Product Description:

The RD51.1-5B-022-L-DF-FW is a drive controller produced by Bosch Rexroth Indramat for the RD 500 Drive Controllers series. It regulates the speed and torque of asynchronous motors used in conveyor lines, mixers, and other material-handling stations. By rectifying incoming three-phase power and then feeding a synthesized voltage waveform to the motor terminals, the unit supports precise acceleration, controlled braking, and continuous speed adjustment so the mechanical load can be coordinated with surrounding automation equipment. This operating method makes the controller suitable for applications that need steady motor behavior as process demand changes during normal production.

A built-in brake chopper dissipates regenerated energy when the motor decelerates, preventing DC-bus overvoltage. Speed regulation follows U/f curve control, meaning the controller keeps a fixed ratio between voltage and frequency to maintain stable torque on squirrel-cage motors. The drive is rated for a continuous mechanical output of 22 kW, allowing it to handle midsize pumps, fans, and extruders without derating. Its input section is designed for mains in the 500 V range, so it ties directly to three-phase networks without an isolation transformer. Thermal management relies on forced air cooling, and an internal fan moves air across heat sinks so full power can be delivered within the specified temperature band. This control approach is well suited to installations that require reliable speed variation without adding unnecessary feedback hardware.

The power section is fed from a 3 x AC converter supply that rectifies each phase before inversion. The device belongs to design 1, indicating the first release of this version. Control terminals include a NAMUR terminal strip with external 24 V standby power, which keeps diagnostic circuitry active even when the main link is open. For diagnostics, the control board also provides current-filter feedback (U6, V6, W6), enabling external meters or a supervisory PLC to monitor the three output currents in real time. These signal connections support status observation during operation and help the drive integrate cleanly with higher-level control systems.