Product Description:

The RD51.1-5N-315-F-LV-FW is a drive controller produced by Bosch Rexroth Indramat within the RD 500 Drive Controllers series. It is intended for variable-speed control of three-phase induction motors in automated machinery and process lines, where stable torque and speed are needed for continuous operation. The unit can be integrated into a centralized control cabinet or linked with higher-level machine control so motor operation follows process demand across conveying, pumping, or ventilation duties. Because it is intended for induction-motor service rather than precision servo positioning, it fits applications that need dependable speed adjustment over a broad operating range.

This model uses U/f curve control, which keeps the voltage and frequency relationship proportional while the motor accelerates and decelerates. The controller is rated for 315 kW, so it is suited to large motor loads that require substantial continuous output. Incoming power must be in the 500 V class, and the unit uses a three-phase AC converter front end to rectify and invert the supply internally. Thermal management is handled by forced-air cooling with integrated liquid circulation, a layout that moves air across a liquid-cooled heat sink to support dense panel installations. The drive is supplied without a built-in brake chopper, so braking energy from overhauling loads must be handled by external equipment.

A diagnostic function provides cable damping feedback (C3, D3), which can help indicate resonance effects on long motor leads. The control electronics can remain active through an external 24 V standby power input, allowing status access and parameter review without energizing the main power section. The unit is part of design generation 1, which places it in the earliest hardware release of this product line. This arrangement supports applications where the control section needs to stay available during service interruptions or when the main supply is intentionally isolated.