Product Description:

Bosch Rexroth Indramat builds the RD51.1-4N-004-L-D1-FW for motion and process applications that rely on variable-speed control of three-phase induction motors. The unit belongs to the RD 500 Drive Controllers series and functions as a closed-loop converter that links line power to the motor through programmable acceleration and deceleration ramps. Within an automation cell, it receives reference setpoints from a PLC or operator panel, adjusts motor voltage and frequency, and helps maintain stable shaft speed when the mechanical load changes.

The controller uses U/f curve control, so output voltage rises in proportion to frequency for open-loop torque regulation across the speed range. It accepts a mains supply of 380 to 480 V and uses a three-phase AC converter topology, which rectifies all incoming phases before converting them back into controlled AC for the motor. Line fluctuations are accommodated by a tolerance window of ±10 %, which helps the drive continue operating through normal supply variation. An integrated mains filter reduces conducted electromagnetic noise, allowing the unit to be installed in control cabinets without requiring additional external filtering hardware in many applications.

Thermal management relies on forced air cooling, with fans that move airflow through the heat sink to keep semiconductor temperatures within the intended operating range during continuous output. The power section is supplied without a built-in brake chopper, so applications with regenerative braking require an external chopper and resistor. Field wiring terminates on a NAMUR terminal strip, which provides a clear interface for control and status connections. Safety-related logic can remain active through a 24 V external stand-by power connection, allowing diagnostic communication to stay available during a main power loss.