Product Description:

The RD51.1-5B-005-D-DF-FW is a drive controller manufactured by Bosch Rexroth Indramat for the RD 500 Drive Controllers series. As a closed-loop power stage, it regulates induction motor speed and torque in automated machinery and material-handling lines. The unit converts fixed mains power into a variable output that follows changing load demand in pumps, conveyors, and processing equipment. Because it adjusts voltage and frequency to the motor, the controller can help the driven machine respond to process changes without abrupt electrical loading.

This model includes a built-in brake chopper that diverts regenerative energy to a resistor during rapid deceleration so the DC bus remains within a safe operating range. It uses U/f curve control, so output voltage rises with frequency to support motor magnetization during low-speed operation. Thermal management relies on a plug-through cooler, which places the heat sink through the cabinet wall and reduces heat buildup inside the enclosure. The controller delivers up to 5.5 kW of output power and is intended for 500 V supply systems. That combination supports basic speed control for general-purpose induction motor applications where simple operating behavior is preferred over more complex control methods.

Input energy is supplied through a three-phase AC converter front end, allowing standard industrial mains to feed the intermediate DC link directly. For control wiring, the unit uses a NAMUR terminal strip with external 24 V standby power, so signaling circuits can remain active when the main supply is unavailable. The external standby supply also helps maintain control availability during brief supply interruptions, which is useful for status retention and orderly fault handling. Diagnostic accuracy is improved by current-filter feedback (U6, V6, W6), which returns filter current signals to the control electronics for monitoring during operation. The unit is in Generation 1, which identifies the product version used for its mechanical layout and compatible option modules.