Product Description:

The RD52.1-4B-055-D-NN-FW drive controller is produced by Bosch Rexroth Indramat within the RD 500 Drive Controllers series. It is intended for cabinet installation, where it converts incoming line power into a regulated output for asynchronous or synchronous motors used in material-handling lines, presses, and packaging stations. By executing internal current and speed loops, the unit relays torque commands received from a PLC and maintains motor performance under load changes. This control structure lets the drive respond smoothly during acceleration, steady running, and braking.

The rated output power is 55 kW, which is the maximum continuous power the controller can deliver to a connected motor. The 380 to 480 V three-phase input allows operation on common plant distribution systems, and the supply remains functional with a line variation of ±10 %, reducing the need for external stabilizers. Because the unit is a 3 x AC converter, it first rectifies the incoming AC, builds a DC link, and then inverts it to a variable-frequency output. Speed and torque are computed with field-oriented vector control, a method that separately adjusts stator flux and torque-producing current for tight dynamic response.

An integrated mains filter suppresses conducted emissions at the drive terminals, which reduces the need for separate external filtering in many installations. Regenerative energy during braking is dissipated by the built-in brake chopper, removing the need for an external resistor interface on moderate-inertia loads. Thermal management is handled by a plug-through cooler, which passes the heat sink outside the enclosure wall so cabinet air recirculation is unnecessary for units up to 110 kW. The drive is design generation 1 and comes without option cards, leaving the base unit focused on its standard power-conversion and motor-control functions.