Product Description:

The RD52.1-4N-055-D-LV-FW drive controller is manufactured by Bosch Rexroth Indramat as part of the RD 500 Drive Controllers series. It forms the power-conversion layer between plant mains and induction or synchronous motors, carrying out closed-loop current and speed regulation in automated conveyors, extruders, and material-handling cells. By accepting three-phase utility power and modulating it under processor control, the unit delivers precise vector-controlled output for industrial motion tasks. This operating approach helps the drive respond smoothly to changing load conditions during continuous and variable-speed operation.

This Generation 1 model uses field-oriented vector control, which allows separate control of torque-producing current and magnetizing current for stable motor performance. The input stage is a three-phase AC converter designed for supplies from 380 to 480 V with a tolerance of ±10%, so it suits common plant distribution systems without tap changes. Its continuous output rating reaches 55 kW, and heat is removed through a plug-through cooler for units up to 110 kW that directs losses toward the cabinet exterior. A factory-installed integrated mains filter reduces conducted emissions on the supply side. The unit does not include a built-in brake chopper, so applications with regenerative energy require an external braking resistor.

The controller also supports cable-damping feedback (C3, D3), which helps compensate for the effects of long motor leads that can distort current waveforms. For emergency conditions or idle fieldbus states, a separate supply terminal accepts external 24 V standby power, allowing the control electronics to remain active when the main power section is de-energized. This arrangement supports continued monitoring, status handling, and control readiness while the main link is inactive. The standby supply and feedback option are useful in systems that rely on external braking or power-fail support modules.