Product Description:

The RS51.1-4G-031-T-NN-FW is a basic drive module produced by Bosch Rexroth Indramat and assigned to the RD 500 Drive Controllers series. As a converter-based unit, it regulates three-phase induction motors in plant automation where speed adjustment is required but full vector regulation is unnecessary. The product belongs to design generation 1, and its role inside a cabinet is to convert fixed-frequency mains power into a variable output that follows a predefined voltage-to-frequency curve. This allows connected machinery to match motor torque to changing process demands without the added complexity of closed-loop vector control.

The drive delivers a rated output of 31 kVA, allowing medium-sized pumps, fans, or conveyors to be started and speed-controlled from a single frame size. It accepts line voltages from 380 to 480 V and works from a three-phase AC supply, so it can be connected directly to standard industrial power distribution networks. Input deviations of up to ±10 % are tolerated without derating, which helps maintain stable operation when plant voltage fluctuates. Motor magnetization follows a U/f curve control profile, and this open-loop method scales output voltage with frequency to keep air-gap flux approximately constant. As a result, motor heating is reduced and setup remains simpler than with vector-controlled drives.

The hardware includes a built-in brake chopper and resistor that dissipate regenerated energy during rapid deceleration. It also uses an integrated mains filter to limit conducted emissions, which reduces the need for external components in the cabinet. Control terminals ship blank because auxiliary functions are not included, leaving only the core power section and basic protective elements in place. Application-specific software is not factory-loaded, and firmware must be ordered as a separate subposition so the drive can be matched to the required parameter set.