Product Description:

The RD51.2-4B-018-L-NN-FW is a drive controller manufactured by Bosch Rexroth Indramat and placed in the RD 500 Drive Controllers series. The unit converts fixed incoming AC power into a variable output for induction-motor speed control in automated machinery such as conveyor lines, pumps, and mixers. This allows the drive to match process demand while maintaining repeatable motor behavior during normal production cycles and staying within torque and thermal limits. It is intended for variable-speed industrial duties where the motor must respond smoothly to changing process conditions.

This controller uses a 3 x AC converter input and accepts line voltages from 380 to 480 V, so it can connect directly to most industrial three-phase power systems. Its continuous output reaches 18.5 kW, which supports medium-sized motors at nominal load without immediate derating in normal operation. Speed regulation is handled by U/f curve control, which maintains a proportional relationship between voltage and frequency to help preserve magnetic flux during speed changes. This control method is suited to applications that need straightforward induction-motor speed regulation. Heat is removed by forced-air cooling, which moves cabinet air across the heat sink to keep semiconductor temperatures within a safe operating range.

A built-in brake chopper dissipates regenerative energy during rapid deceleration, so an external braking module is not required for that function. An integrated line filter reduces conducted noise toward other equipment on the supply and helps limit electrical interference in the system. The power section tolerates supply variation of up to ±10%, which helps the controller remain stable when line voltage shifts within the permitted range. The unit is part of generation 2 of the RD platform, and its standard hardware leaves expansion positions open for optional I/O cards. Those open positions allow added interface functions when the application requires them.