Product Description:

The RD51.1-4N-045-D-NN-FW is a drive controller manufactured by Bosch Rexroth Indramat for the RD 500 Drive Controllers series. Mounted in an automation cabinet, it converts fixed three-phase power into a variable motor output for pumps, fans, and material-handling equipment used throughout industrial plants. Its primary task is to modulate motor speed and torque so that connected machinery can run at process-specific setpoints instead of constant line frequency. This operating role makes it suitable for applications that need adjustable motor behavior during startup, normal running, and controlled speed changes.

Speed modulation is executed through U/f curve control, a method that keeps motor flux approximately constant across the commanded speed range without closed-loop feedback. The inverter section is rated at 45 kW, which suits mid-range industrial loads such as process pumps, blowers, and conveyor drives. The controller accepts line voltages from 380 to 480 V, and a tolerance of ±10 % helps it continue operating through normal plant supply variation. Heat is removed by a plug-through cooler for units up to 110 kW, so the heat sink passes through the rear panel and reduces heat buildup inside the cabinet. This control method is often used where straightforward speed regulation is sufficient and encoder-based feedback is not required.

The mains connection uses a three-phase AC converter connection, matching standard industrial power systems. The unit is supplied without a built-in brake chopper, so regenerative energy from decelerating loads must be handled by external braking hardware when the application requires it. An integrated mains filter reduces conducted interference on the incoming line and helps simplify panel integration in electrically sensitive installations. The unit is Design 1. This arrangement is appropriate for cabinet-based drive systems where braking components and other added functions are provided separately from the main controller.