Product Description:

The RD51.1-4N-005-L-NN-FW/S111 is a drive controller produced by Bosch Rexroth Indramat within the RD 500 Drive Controllers series. In inverter-based automation lines, it regulates three-phase induction motors so shaft speed and torque can be adjusted without mechanical gear changes. By converting fixed supply power into variable-frequency output, the unit supports conveyors, pumps, and material-handling equipment while helping reduce mechanical wear and unnecessary energy use. This operating principle is well suited to applications that need steady variable-speed motor control during normal process changes.

This controller connects to a three-phase supply through a three-phase AC converter input and operates across 380 to 480 V lines with a voltage tolerance of ±10%. At the output side, it delivers a nominal power of 5.5 kW, which suits mid-range fan wheels, mixers, or hoist drives in variable-speed service. Open-loop regulation uses U/f curve control, so stator flux remains proportional to frequency across the usable speed range and motor operation stays predictable under changing load conditions.

Thermal dissipation is handled by forced air cooling, and the airflow path directs heat away from the power semiconductors in typical cabinet installations. Line-side interference is reduced by an integrated mains filter, which can remove the need for additional EMC components in many installations and helps limit conducted noise on the supply connection. The power stage is supplied without a built-in brake chopper, so braking energy must be managed by external hardware when rapid deceleration is required. Front-panel option slots are present but not populated, which keeps the housing compact when extra I/O is unnecessary. That arrangement leaves room for application-specific expansion without changing the basic enclosure size. As a design generation 1 variant, the unit uses the established RD51.1 platform layout and mounting pattern.