Product Description:

The RD51.1-5N-018-D-D1-FW is a drive controller produced by Bosch Rexroth Indramat for the RD 500 Drive Controllers series. Acting as the central power stage between a control system and a three-phase induction motor, the unit modulates stator voltage and frequency so conveyor lines, pumps, or material-handling axes can follow commanded speeds. By integrating into common switchgear cabinets, the controller enables precise torque regulation, coordinated startup sequences, and energy-optimized operation in automated manufacturing cells. This operating method also supports smooth acceleration and deceleration, which helps reduce abrupt load changes in connected equipment.

The device employs U/f curve control, so the ratio between output voltage and frequency remains fixed across the speed range, a method suited to standard induction motors that do not require vector feedback. Its nominal output is 18.5 kW, matching medium-sized fan or pump drives. Power is drawn through a three-phase AC converter supply that accepts mains within the industrial 500 V range, allowing direct connection to high-voltage distribution panels. Thermal management is handled by a plug-through cooler (≤ 110 kW); the heat sink extends outside the enclosure so cabinet air remains cooler and component life is prolonged. This control approach is commonly used where steady speed regulation is more important than rapid servo-style response.

The controller is built without a built-in brake chopper, so any dynamic braking energy must be routed to an external resistor or recovered by the supply. Its Generation 1 design supports compatibility with early RD 500 accessories. Field wiring is streamlined by the NAMUR terminal strip, and an auxiliary external 24 V standby power input keeps the control logic energized during mains outages for orderly shutdown routines. These interface points support diagnostics and allow remote safety circuits to remain active even when the main inverter stage is de-energized.