Product Description:

The RS51.1-4G-050-V-NN-FW is a basic drive controller produced by Bosch Rexroth Indramat in the RD 500 Drive Controllers series. It is intended for cabinet-mounted applications that require variable-speed control of three-phase induction motors, including conveyors, fans, and process pumps. Because it is installed in a cabinet, the power electronics remain protected while the drive handles motor speed changes electronically. This makes it suitable for equipment that needs smooth starts, adjustable running speed, and reduced mechanical shock during load changes.

The drive delivers a continuous apparent power of 50 kVA, giving sufficient headroom for medium-sized motor loads. Its input terminals accept line voltages from 380 to 480 V and remain operational within ±10 % of the nominal value, which helps accommodate normal utility variation. Supply wiring is three-phase because the unit is classified as a Converter 3 x AC. Speed regulation uses U/f curve control, so motor flux remains proportional to frequency and torque stays stable across the working range. This control method works well for induction motors that do not require encoder feedback or highly dynamic positioning.

A built-in brake chopper and resistor is fitted to absorb regenerated energy during rapid deceleration, preventing DC-bus overvoltage without an external braking module. This is useful on loads that return energy while slowing, such as high-inertia fans or descending conveyor sections. Line-side interference is reduced by an integrated line filter that attenuates conducted emissions before they return to the supply network. The unit is part of generation 1 of the RD 500 platform, and its application software is ordered separately. This arrangement allows the power section to be matched to the intended feature set without changing the base hardware.