Product Description:

The RD51.1-4B-011-L-NN-FW is a drive controller produced by Bosch Rexroth Indramat within the RD 500 Drive Controllers series. As a converter-based module, it interfaces between a three-phase line supply and an induction motor to regulate speed and torque in automated material-handling or process lines. By modulating output frequency along a preset voltage-to-frequency profile, the unit provides basic open-loop control for pumps, fans, and conveyors where feedback is not mandatory. The controller is typically used where stable variable-speed operation is needed without servo-style positioning functions.

Input compatibility spans 380 to 480 V three-phase networks, and the internal front end is a Converter 3 x AC stage. Once converted, the controller applies U/f curve control, which maintains a constant ratio between output voltage and frequency so motor flux stays within its linear range. Transient energy returned during deceleration is dissipated through the built-in brake chopper, which helps prevent DC-bus overvoltage without external hardware. Thermal stability is supported by forced air cooling, so installation requires unobstructed airflow paths. Design generation 1 hardware also contains diagnostic LEDs that indicate overcurrent, overtemperature, or line loss for quick fault identification.

Line-conducted noise is reduced by the integrated mains filter, making additional cabinet filters unnecessary in most installations and keeping wiring compact. Output accuracy remains within ±10 % of set values across the stated temperature and load range, which simplifies drive sizing for loads that can tolerate modest speed variation. The option slot is left not equipped, leaving space for fieldbus or I/O cards when needed. Control firmware must be ordered as a separate subposition, so the software package can be matched to the intended application.