Product Description:

The RD51.1-4B-090-L-CF-FW is a drive controller produced by Bosch Rexroth Indramat and belongs to the RD 500 Drive Controllers series. It regulates the speed and torque of three-phase induction motors in industrial automation lines, providing closed-loop integration with higher-level PLCs. By modulating output frequency and voltage, the unit lets conveyor, pump, or fan assemblies follow process demands and reduce electrical consumption.

This controller uses a three-phase AC converter supply and is designed for mains systems from 380 to 480 V. The permissible input fluctuation is ±10 %, giving margin for facilities where line voltage rises or dips. At the motor terminals, the device can deliver up to 90 kW of continuous mechanical output, fitting medium-sized machinery and ventilation drives. A built-in brake chopper dissipates regenerative energy into a resistor during deceleration to prevent DC-bus overvoltage. The firmware is supplied separately, so application-specific software can be selected without replacing the power stage.

In operation, the RD51 controller regulates motor flux with U/f curve control, a scalar technique that keeps the ratio of stator voltage to frequency constant and is suited to standard induction motors that do not need vector feedback. Heat is removed by forced air cooling, so the unit requires unobstructed airflow paths inside the cabinet and routine filter maintenance. An integrated mains filter attenuates conducted electromagnetic noise, allowing compliance with factory EMC limits without adding external line filters. Function combination C1 + F1 equips the device with a base control board and an additional option card for expanded I/O and fault monitoring, while the internal hardware follows design generation 1 for compatibility with earlier RD 500 accessories.