Product Description:

The RD51.2-4B-015-L-A2-FW/S122 is a drive controller produced by Bosch Rexroth Indramat within the RD 500 Drive Controllers series. This unit converts three-phase AC power into a regulated output for induction motors and other actuators, enabling speed and torque adjustment in automated production lines, conveyor sections, and process equipment. As a mid-range member of the product family, it interfaces with higher-level PLCs and fieldbus hardware to execute command profiles while supplying diagnostic feedback for closed-loop plant operation. Its control functions support variable-speed duty where stable motor response is needed as process loads change.

At the core of its power stage, the controller delivers a rated output of 15.0 kW, enough for medium-sized pump or fan drives without oversizing the cabinet supply. It is fed by three-phase AC power and accepts line voltages from 380 to 480 V, so it can be wired directly to standard industrial mains. Motor flux is regulated through U/f curve control, an open-loop method that keeps the voltage-to-frequency ratio constant to preserve torque across the usable speed range. Thermal energy is removed by forced air cooling, which draws ambient air through the heat sink and helps maintain stable semiconductor temperatures during continuous operation.

The built-in brake chopper dissipates regenerative energy whenever the DC-link voltage rises during rapid deceleration, reducing the need for separate braking components. That arrangement is useful in systems with frequent deceleration cycles or overhauling loads. Supply deviations are tolerated within ±10 % of nominal, and harmonic suppression is aided by an integrated mains filter that lowers conducted EMI on the incoming line. This controller belongs to design generation 2 and includes external standby power together with a starting lockout function that helps prevent unintended run commands during maintenance and keeps control logic available when the main power stage is inactive.