Product Description:

The RD51.1-5B-005-L-CF-FW is produced by Bosch Rexroth Indramat as part of the RD 500 Drive Controllers series. This inverter-based unit sits between three-phase mains and an asynchronous motor, converting fixed line power into variable frequency and voltage that match the needs of the driven process. Mounted in a switchgear cabinet, it works through external control terminals so conveyors, pumps, and material-handling axes can receive coordinated speed commands and controlled stopping signals from the central automation system. It also supervises overload behavior and stopping ramps so the motor can respond predictably during routine starts, speed changes, and shutdowns. Its role is to provide adjustable motor operation while supporting stable speed control during changing load conditions.

Power enters through a three-phase AC input that is compatible with plant grids up to 500 V line to line. From this supply, the controller can deliver 5.5 kW of output power to a connected motor during continuous duty. Regulation uses U/f curve control, which maintains the voltage-to-frequency ratio so stator flux remains stable during acceleration and load changes. This control method is commonly used where simple, reliable speed adjustment is needed without closed-loop vector operation. Internal losses are removed by forced-air cooling, so cabinet airflow must remain unobstructed across the heat sink. During deceleration, a built-in brake chopper diverts excess DC-bus energy to an external resistor to keep the intermediate circuit within its intended operating range.

The controller is identified as Design Generation 1, so its mechanical outline, terminal arrangement, and control interface correspond to the earliest RD51 release. The internal feature set marked Combination C1 + F1 adds selectable braking profiles and frequency filters beyond the basic operating mode. Those added functions help smooth deceleration behavior and can reduce unwanted electrical effects at the motor terminals. The controller is used in variable-speed industrial systems where stable motor regulation and braking support are required.