Product Description:

The RD51.1-4N-003-L-D1-FW is a drive controller manufactured by Bosch Rexroth Indramat and assigned to the RD 500 Drive Controllers series. It operates between a three-phase mains supply and asynchronous motors, adjusting voltage and frequency so automated machinery can match changing process demands. This makes the unit suitable for variable-speed industrial equipment that needs controlled motor operation rather than fixed-speed line power. The controller also accepts an external 24 V standby supply, which allows the control section to remain energized for monitoring when the main power is removed.

This model delivers a rated output of 3.0 kW, which suits medium-duty drives in general plant equipment. It accepts line voltages from 380 to 480 V and remains operational within a tolerance window of ±10 %, so normal supply variation does not interrupt operation. The supply arrangement is a 3 × AC converter, with rectification and DC-link components built into one frame for direct connection to a three-phase network. Speed regulation uses U/f curve control, which keeps the ratio between stator voltage and frequency constant during operation. This control method is appropriate for standard induction motors that do not require sensor-based vector control.

The unit operates without a built-in brake chopper, so applications that return regenerative energy require an external braking resistor. Thermal management relies on forced air cooling; air is directed through the heat sink to keep semiconductor temperatures within an acceptable operating range. The controller includes an integrated mains filter, which helps reduce conducted emissions and simplifies cabinet wiring by reducing the number of separate components. Its control connections use a NAMUR terminal strip pattern, a layout commonly used in process and chemical plants. This terminal arrangement supports orderly connection of command, reference, and status wiring.