Product Description:

The RD51.1-5B-037-D-D1-FW is produced by Bosch Rexroth Indramat within the RD 500 Drive Controllers series. It is installed in automated plants to modulate the speed of three-phase induction motors by converting fixed mains power into a regulated output suited to process requirements. The controller supports open-loop voltage-to-frequency operation, so conveyors, pumps, and fans can run at the commanded speed without a separate motor feedback device. This operating method is well suited to variable-speed process equipment that needs reliable speed adjustment rather than closed-loop positioning accuracy.

The controller employs U/f curve control, maintaining constant magnetic flux by adjusting voltage in proportion to frequency. Its input section uses a Converter 3 x AC design for direct connection to industrial three-phase supplies centered on 500 V. The power stage is rated for 37 kW of continuous motor output. Heat is removed by a Plug-through cooler, which transfers heat sink losses outside the cabinet wall and helps reduce internal enclosure temperature. A built-in brake chopper absorbs regenerative energy during deceleration, which supports controlled stopping of high-inertia loads and reduces stress on the DC bus.

The integrated Built-in brake chopper shortens braking time on loads that return energy during deceleration. A NAMUR terminal strip groups control wiring on clearly labeled spring contacts, and an external 24 V standby power supply keeps the control electronics active during brief mains interruptions. The grouped terminal layout helps separate command, status, and interlock wiring inside the panel. The unit is Design generation 1, which identifies the first design release. During a power dip, the standby supply allows status handling and orderly shutdown behavior while the power section is inactive.