Product Description:

The RD51.1-4N-200-F-V1-FW drive controller is manufactured by Bosch Rexroth Indramat as part of the RD 500 Drive Controllers series. Deployed in industrial automation cells, it interfaces between a three-phase mains bus and an AC induction motor. It modulates voltage and frequency so that machinery such as conveyors, pumps, or mixers can run at commanded speeds while maintaining torque requirements. This supports variable-speed operation in applications that do not need the motor to run at fixed line frequency at all times.

This model is supplied without a built-in brake chopper, so an external energy-dissipation circuit is required when rapid deceleration is expected. Speed regulation follows U/f curve control, so the controller maintains a constant volts-per-hertz ratio to keep motor flux stable over the operating range. The power section is rated at 200 kW, giving it the capacity for high-horsepower installations that draw heavy continuous current. It accepts line voltages from 380–480 V, and its input window allows a tolerance of ±10 %, so the unit can remain operational during moderate mains fluctuation without nuisance trips. These values help match the controller to the available supply and connected motor load.

Thermal management is handled by forced air cooling with integrated liquid circulation. The liquid loop removes heat from the heat sink while the fan transfers it to ambient air, supporting full output during elevated duty cycles. An integrated mains filter attenuates conducted electromagnetic noise, so no separate line filter is required. The power stage is built as a converter 3 × AC, meaning it rectifies three-phase input and reconstructs a variable AC waveform for the motor. Control electronics remain energized through 24 V standby power supplied from an external source, so fieldbus communication and diagnostics stay active even when the main circuit is isolated.