Product Description:

The RD52.1-7N-055-L-NN-FW is a drive controller produced by Bosch Rexroth Indramat and assigned to the RD 500 Drive Controllers series. In an industrial automation line, it converts DC-bus energy into precisely regulated three-phase output, enabling variable-speed operation of induction motors used on conveyors, extruders, and similar continuous-duty equipment. Acting as the final power element between a motion processor and the motor windings, it translates low-level speed or torque references from a PLC into high-current waveforms that match changing load demands. This operating role supports stable motor performance where process speed must remain consistent as the mechanical load varies.

It implements field-oriented vector control, allowing the stator current to be separated into torque-producing and flux-producing components so motor torque can follow reference commands with high accuracy. The unit draws power from an inverter DC link fed by a common supply section and is optimized for a DC-bus window of 530 to 670 V. Under these conditions, it can deliver up to 55 kW of output to the connected motor group. Thermal losses are removed through forced-air cooling, and integrated fans move cabinet air across the heat sink to keep semiconductor junction temperatures within permissible limits during continuous duty.

The controller operates without a built-in brake chopper, so it relies on external braking modules or regenerative operation to handle surplus kinetic energy produced during rapid deceleration cycles. When braking energy cannot be returned to the supply, a separate dissipation path is needed to keep DC-bus voltage within the allowable range. The unit is built to design generation 1, with mechanical dimensions and interface layouts consistent with the earliest RD 500 release. For application matching, firmware is ordered separately and loaded into the unit before use. The expansion slots are not equipped, leaving space for optional add-on cards such as I/O terminals or communication adapters if the application requires them.