Product Description:

The RD51.1-5N-055-L-DL-FW belongs to the RD 500 Drive Controllers series manufactured by Bosch Rexroth Indramat. Designed as a variable-speed AC converter, it interfaces between a three-phase mains supply and standard induction motors found in conveyors, pumps, and general factory machinery. By modulating output frequency and voltage, the unit provides closed-loop speed regulation that reduces mechanical stress and energy consumption in automated production lines. Its hardware platform supports optional firmware modules so end users can tailor control behavior to the target process.

Motor regulation is achieved with U/f curve control, a scalar technique that maintains a constant ratio between voltage and frequency to keep flux within the motor’s optimal range. The drive draws power through a Converter 3 x AC input architecture and is specified for a mains window centered on 500 V, making it suitable for high-voltage distribution boards. Under those conditions it can deliver a continuous shaft capability of 55 kW, a rating that defines the maximum mechanical output the connected motor may absorb. Thermal loads produced during that duty are removed by forced air cooling, which channels cabinet air across the heat sink and avoids external liquid circuits.

The cooling airflow, together with efficient silicon switching, eliminates the need for an internal dynamic resistor because the unit is supplied without a built-in brake chopper; braking energy must therefore be routed to an external module when rapid deceleration is required. Hardware identification marks it as design generation 1, ensuring compatibility with first-generation RD 500 option cards and firmware. Control wiring is simplified by the NAMUR terminal strip, 24 V stand-by power external, so digital inputs remain alive during mains outages for fieldbus diagnostics. For installations with long motor leads, the adjustable feedback of cable damping (C3, D3) function compensates resonance and maintains a stable U/f profile.