Product Description:

The RD42.1-4R-105-L is a drive controller produced by Bosch Rexroth Indramat and belongs to the RD 500 Drive Controllers series. It is designed to interface between a three-phase mains supply and asynchronous or synchronous motors, adjusting output frequency and voltage so a supervisory PLC can command start, stop, and speed ramps with accuracy. Within automated conveyors, packaging stations, and general motion axes, the unit provides the closed-loop regulation needed to maintain constant torque under shifting mechanical loads. This type of control helps keep motor behavior steady when process resistance or conveyor loading changes during operation.

The controller is built to Design Generation 1. It operates from an input range of 380 to 480 V, a common industrial range that supports installation in a wide variety of panels. The power stage is fed from a 3 x AC converter input, so the three line phases are rectified before the inverter section modulates them for motor control. Input fluctuations are handled by a ±10% tolerance, which helps the drive remain stable during temporary voltage sag or swell. To reduce conducted emissions and limit harmonic feedback, an integrated mains filter is already installed. With the filter built in, the line side of the installation can often remain simpler than with a separate external filter assembly.

Thermal management relies on forced-air cooling, so a dedicated fan moves air across the heat sink and allows the module to deliver rated current without external chillers. The drive is supplied without a brake chopper, so regenerated energy from overhauling loads is not dissipated inside the unit. In applications with frequent deceleration or driven loads, that returned energy must be handled by the supply side or by a separate braking solution. Cabinet layouts also need a clear airflow path so warmed air can leave the enclosure efficiently during continuous operation.