Product Description:

The RD52.1-4N-075-L-V1-FW is a drive controller produced by Bosch Rexroth Indramat and positioned within the RD 500 Drive Controllers series. Used in industrial automation, the unit acts as the power-processing interface between the plant power supply and an AC motor, adjusting voltage and frequency so that speed and torque follow programmed process profiles. By modulating output to match command signals, it supports stable acceleration, deceleration, and steady-state speed control in conveyors, pumps, and extruders. The unit can be installed in centralized or distributed control cabinets where coordinated motor control is required across changing load conditions.

The controller is sized for 75 kW continuous output and connects to plant power across a 380 to 480 V range. Allowable line deviation is limited to ±10 %, which helps the device remain operational during moderate supply swings without interrupting normal drive behavior. Internally, it uses field-oriented vector control to keep motor flux and torque linear, enabling rapid response to load changes and improved control at lower speeds. Heat is removed by forced air cooling, so cabinet airflow must be maintained around the unit during operation. The power section is fed from a three-phase AC supply, and its rectification and inversion stages create the regulated output needed to drive induction or synchronous machines.

The unit is in design generation 1. It operates without a built-in brake chopper, so dynamic braking energy must be diverted through an external module when the application requires controlled deceleration of high-inertia loads. The controller includes an integrated mains filter, which reduces conducted emissions and can reduce the need for additional line filtering inside the cabinet. During power loss on the main bus, an auxiliary 24 V stand-by power input keeps the control electronics active for diagnostics and fieldbus communication. This allows status information to remain available while the main power path is no longer supplying the motor section.