Product Description:

The RD52.1-7N-090-L-NN-FW is a drive controller released by Bosch Rexroth Indramat within the RD 500 Drive Controllers series. It converts DC link energy from a common supply into a three-phase output for induction or synchronous motors used in automated machinery. In industrial automation, the module provides closed-loop speed and torque regulation so conveyors, extruders, and processing lines can run at commanded operating points with minimal fluctuation. It mounts in control cabinets and works with matching RD rectifier and line filter components to form a complete variable-frequency system.

The controller is rated for 90 kW, allowing it to drive medium-to-large motors in continuous production cycles without derating. It accepts a DC bus range of 530 to 670 V, which matches the rectified output of 400 V class mains and gives the inverter enough headroom for dynamic torque boosts. Current and flux are managed through field-oriented vector control, so motor response remains stable even at low speeds. Thermal energy is removed by forced-air cooling, which means cabinet airflow must be maintained to keep the heat sink within its permitted temperature range. Because the unit is supplied from an inverter DC link instead of direct mains, multiple controllers can share a common supply and braking network.

The mechanical frame belongs to design generation 1, so it follows the mounting and interface pattern used by other first-generation RD modules. For applications that demand rapid deceleration, the unit is supplied without a built-in brake chopper, so an external chopper and resistor are required if regenerative energy exceeds the DC bus capacity. The unit comes without ancillary options, which leaves internal expansion space available for optional I/O or communication boards. Control software is not preinstalled; software must be ordered separately so the machine can use the required operating package.