Product Description:

The RD51.1-5N-315-R-V1-FW is a drive controller produced by Bosch Rexroth Indramat within the RD 500 Drive Controllers series. It modulates the electrical supply delivered to large three-phase induction motors, allowing speed and torque adjustment from a cabinet-mounted unit instead of by mechanical throttling. In automated material-handling lines, continuous-duty pumps, and high-capacity fans, the controller converts fixed mains power into variable output so motor speed can track process demand while helping protect connected motors from overload. It is intended for heavy industrial duties where stable operation across long run times is more important than short burst performance.

Control is achieved through U/f curve control, a scalar method that keeps the voltage-to-frequency ratio constant so magnetic flux inside the motor remains stable across the speed range. For thermal management, the unit uses liquid cooling with an internal pump for ratings of 132 kW and above, and circulating coolant removes heat from the power electronics during sustained operation. This cooling method supports the drive’s 315 kW output rating in high-load applications. The input stage is a 3 × AC converter that accepts grid power centered around 500 V, allowing the controller to operate from industrial three-phase mains. Because this is a scalar control method, it is commonly used where reliable speed regulation is more important than highly dynamic positioning response.

The drive operates without a built-in brake chopper, so energy created during rapid deceleration must be handled by an external resistor or a regenerative supply path. A dedicated logic supply uses external 24 V standby power, which keeps the control electronics active when the main power line is isolated. Keeping the logic supply separate also supports diagnostics and status retention while the power section is turned off. The unit is part of Design Generation 1, and the drive uses firmware ordered as a separate subposition so the software package can be matched to the required application. This arrangement allows the operating software to be selected for the intended machine function without changing the main hardware.