Product Description:

The RD51.1-4N-018-D-NN-FW is a drive controller produced by Bosch Rexroth Indramat for the RD 500 Drive Controllers series. It is installed in automation cabinets to regulate three-phase induction motors by adjusting stator voltage and frequency. In industrial lines, it supports speed or torque control through a predefined motor characteristic, giving the connected machine a straightforward way to match motor behavior to process demands. This operating method is commonly used in pumps, fans, and conveying equipment where adjustable motor speed is needed during normal production.

This model delivers a rated output of 18.5 kW, a power level suited to medium-sized pumps, blowers, and material-handling axes. The supply section accepts line voltages from 380 to 480 V and maintains performance within a tolerance of ±10 %, allowing operation on industrial mains with modest fluctuation. Because the input range covers common plant power systems, the controller can be applied in facilities with slightly different nominal voltages without changing the basic operating concept. It is configured as a three-phase AC converter, so three incoming phases are rectified and then inverted to a variable-frequency output for the motor. Motor control is handled by U/f curve control, which links output frequency to voltage for straightforward speed regulation in applications that do not require complex vector control.

Thermal management is provided by a plug-through cooler, which directs most heat outside the enclosure and helps reduce cabinet airflow demand. By moving a large share of the heat away from the cabinet interior, this layout can help limit temperature rise around neighboring electrical components. The unit comes without a built-in brake chopper, so applications with frequent or rapid deceleration require external braking hardware to handle returned energy. Line-side harmonics are reduced by an integrated mains filter, which can remove the need for a separate filter section in many installations and helps reduce conducted noise on the supply. The unit is Design generation 1.