Product Description:

The RD51.1-4N-003-L-NN-FW/S111 is a drive controller in the RD 500 Drive Controllers series manufactured by Bosch Rexroth Indramat. The unit forms the core of variable-speed induction motor loops, translating command signals into controlled voltage and frequency output for conveyors, mixers, and similar plant equipment. In typical installations, it receives run, stop, and speed references from higher-level controls and converts them into motor output appropriate for the connected load. It is supplied as a functional module, so the operating software is selected separately for the intended machine section.

The unit accepts a three-phase line supply of 380–480 V, which fits common industrial power systems. Within that range, it tolerates input variation of ±10 % without normal output instability. The power stage is rated at 3.0 kW, making it suitable for small process motors that need consistent speed control during routine operation. Motor regulation uses U/f curve control, which keeps the voltage-to-frequency relationship proportional across the speed range and supports operation without sensor feedback. Incoming power passes through an integrated mains filter, which helps limit conducted emissions inside the cabinet and reduces the need for separate filtering components in basic installations.

Heat is removed by forced air cooling, so the controller must be installed where cabinet airflow can pass over the heat sink. The cooling path should remain clear so warmed air can move away from the power section during operation. The supply stage uses a three-phase AC converter topology for standard industrial power input. This variant is supplied without a built-in brake chopper, so applications with frequent deceleration require an external braking solution. The unit uses a generation 1 design, and the NN code indicates that no application-specific options are installed.