Product Description:

The RD51.1-5B-110-L-DL-FW is a drive controller produced by Bosch Rexroth Indramat and belongs to the RD 500 Drive Controllers series. In an automation cell, it links the three-phase mains to an induction motor, shaping voltage and frequency so a conveyor, fan, or pump can follow programmed speed profiles. By converting fixed-frequency line power into variable output, the unit supports consistent acceleration, controlled deceleration, and reliable handling of regenerative energy. This makes it suitable for variable-speed duties where direct-on-line motor starting would be too abrupt for the process.

At the output stage, the controller can deliver 110 kW of drive power when connected to motors sized for heavy continuous duty. Regulation is organized through U/f curve control, an open-loop method that keeps the volts-per-hertz ratio constant to avoid magnetic saturation at low speeds. A built-in brake chopper is integrated on the DC link so excess regenerative energy is routed to a resistor instead of raising the bus voltage. Internal temperatures are maintained by forced air cooling, which uses dedicated fans to push airflow across heat sink fins. The line connection is rated for 500 V, giving the converter headroom for typical 400 V industrial supplies while still allowing field weakening at higher frequencies.

Power is fed through a three-phase AC converter front end that rectifies each phase and energizes the shared DC bus for downstream inverters. Control and safety wiring terminates on the NAMUR terminal strip, and an external 24 V stand-by source keeps the logic active during mains outages. For long motor leads, the unit provides cable damping feedback, which lets the drive compensate for reflected waves in lengthy or highly capacitive runs. Operational parameters reside in flash memory, allowing retained settings after normal power removal.