Product Description:

The RD51.2-4B-007-L-A1-FW drive controller is produced by Bosch Rexroth Indramat and belongs to the RD 500 Drive Controllers series. Installed between a three-phase supply and an induction motor, it converts incoming line power into controlled voltage and frequency for variable-speed operation. This allows automated machines to accelerate smoothly, hold a steady operating speed, and decelerate with less mechanical shock. When the drive receives commands from a PLC or fieldbus master, it can support stable operation in conveyors, mixers, pumps, and similar industrial equipment where repeatable motor control is important.

Its continuous output is rated at 7.5 kW, which suits mid-range production motors used in general automation duty. The input section uses a three-phase AC converter stage and accepts utility power from 380 to 480 V. Internal bus capacitors and gate drivers tolerate supply variation of ±10%, which helps the unit remain stable during normal plant voltage fluctuation. A built-in brake chopper is connected to the DC link so regenerated energy can be directed to a braking resistor during fast stops or overhauling loads. This helps keep the intermediate circuit voltage within an acceptable range during deceleration and reduces nuisance shutdowns in applications with frequent speed changes.

Speed control is handled through U/f curve control, which maintains a consistent volts-per-hertz relationship so motor flux remains stable across the commanded speed range. Heat is removed by forced air cooling, allowing the enclosure to operate at full load in cabinets where components are mounted close together. An integrated mains filter reduces conducted electromagnetic interference on the supply connection, which can simplify installation in industrial power systems. For reduced idle consumption, the control board supports external stand-by power. The drive also includes a starting lockout function to help prevent unintended motor startup during control or supply transitions.