Product Description:

The RD52.1-4N-090-L-NN-FW is a drive controller produced by Bosch Rexroth Indramat within the RD 500 Drive Controllers series. As a drive controller, it converts fixed-frequency mains power into regulated output for induction or synchronous motors, enabling programmable speed and torque profiles in automated machinery and process lines. This operating role suits installations that need controlled acceleration, stable running speed, and repeatable response under changing process demand. It can be used where a central drive must coordinate motor output with process timing, especially in equipment that cannot tolerate abrupt torque swings or unstable low-speed behavior.

This model delivers a rated output of 90 kW, providing enough power for large pumps, extruders, and conveying systems. It accepts line voltages from 380 to 480 V, so it can be installed on standard industrial networks without an isolation transformer. The supply interface uses a three-phase AC converter arrangement that rectifies and inverts the incoming utility feed. Thermal management relies on forced air cooling, with internal fans moving air across the heat sink to keep semiconductor temperatures within safe limits during continuous high-load operation. Electrical noise on the mains is reduced by the integrated mains filter, which helps limit conducted interference on nearby equipment and supports cleaner power conditions in shared industrial installations.

The control loop is based on field-oriented vector control, allowing precise motor flux and torque regulation at low speed as well as fast response under load changes. This method also helps the drive maintain smooth torque production during startup and while the mechanical load changes rapidly. The unit is supplied without a built-in brake chopper, so applications that require dynamic braking must use an external resistor or braking module. As a generation 1 design, it is compatible with the first release of RD 500 options and accessories. Input variation of up to ±10 % is permitted, allowing the controller to continue operating when line voltage fluctuates within that window.