Product Description:

The RD51.1-5B-090-D-D1-FW drive controller is produced by Bosch Rexroth Indramat and belongs to the RD 500 Drive Controllers series. As a standalone power electronics unit, the controller forms the interface between the plant’s three-phase mains and an induction motor, converting supply energy into a regulated output that controls motor speed and torque. It is intended for variable-speed operation in conveyors, pumps, and process lines where output must respond to changing production conditions and continuous-duty requirements. In these applications, it provides closed-loop adjustment so that mechanical motion follows programmed sequences and changing load demands without the need for manual intervention.

The unit is fed from a three-phase AC converter supply and is optimized for 500 V-class grids. Internally, it supports mechanical loads up to 90 kW at the motor shaft, making it suitable for substantial industrial drive duty. Speed regulation uses U/f curve control, so the voltage-to-frequency ratio remains constant and the magnetic flux in a standard induction motor stays stable across the speed range. At lower speeds, this method helps the motor maintain usable magnetization during normal load changes. Thermal energy from the power modules is removed through a plug-through cooler for units up to 110 kW, which passes the heat sink through the cabinet wall so most heat is dissipated outside the enclosure and cabinet temperature stays lower.

Dynamic braking energy is handled by a built-in brake chopper, eliminating the need for an external resistor trigger circuit during rapid deceleration. Field wiring is routed to a NAMUR terminal strip, which provides a standardized connection layout for sensors and interlock loops used by surrounding equipment. When incoming power is removed, the control electronics can remain active from an external 24 V standby power supply, allowing stored settings and communication functions to remain available during short interruptions. The unit is part of Design generation 1, indicating the first design release of this controller type.