Product Description:

The RD51.1-4N-110-L-NN-FW is a drive controller from the RD 500 Drive Controllers series produced by Bosch Rexroth Indramat. Installed between a plant PLC and an induction motor, it converts control references into variable output voltage and frequency so that conveyors, pumps, or fans can follow precise speed profiles. The unit mounts in a cabinet and supports modular automation systems that require motor efficiency, soft starting, and repeatable operation during continuous industrial service. This arrangement is well suited to applications where steady motor control is more important than highly dynamic servo response.

The controller accepts a three-phase input through a Converter 3 x AC input section and operates within a supply range of 380 to 480 V. Line variations are handled by an internal tolerance of ±10 %, which helps the unit remain stable during moderate power fluctuations. Thermal energy from the power section is removed by forced air cooling, with built-in fans moving cabinet air across the heat sink. Electromagnetic emissions to upstream wiring are reduced by an integrated mains filter, which can simplify panel layout in systems that need cleaner line conditions. The cooling and filtering arrangement supports long operating periods in enclosed industrial cabinets.

A maximum output of 110 kW places the unit in a range suitable for medium-sized motor groups where strong starting demand is common. Speed regulation uses U/f curve control, a method that works well with standard squirrel-cage induction motors in general-purpose variable-speed applications. Dynamic braking energy must be managed externally because the controller is supplied without a built-in brake chopper. The unit is part of design generation 1 and uses the mechanical dimensions and terminal layout associated with early RD controllers. This makes it easier to integrate into existing cabinet arrangements that were prepared for the same product generation.