Product Description:

The RD51.1-5B-018-L-CF-FW is a drive controller manufactured by Bosch Rexroth Indramat within the RD 500 Drive Controllers series. It is intended for variable-speed operation of three-phase induction motors in factory automation, material handling, and process equipment. By converting fixed-frequency mains power into an adjustable output, the unit lets PLCs and local panels command motor speed, acceleration, and braking to match changing load demands while supporting smoother starts and controlled stops. This operating method allows one controller to serve applications that need steady-speed running as well as controlled ramps during changing process conditions.

A built-in brake chopper routes regenerated energy to a resistor during deceleration, which helps prevent DC-bus overvoltage faults. Speed regulation is handled through U/f curve control, which maintains a proportional relationship between stator voltage and frequency to support stable motor flux across low and nominal speeds. Thermal limits are managed by forced air cooling, so unobstructed airflow through the heat sink channel is required for continuous duty. The inverter section delivers up to 18.5 kW of mechanical power for pumps, fans, and conveyors in the mid-range power class. The unit operates as a 3 x AC converter, rectifying the incoming three-phase supply and producing a pulse-width-modulated output with adjustable frequency and amplitude.

The input network is designed for a nominal line voltage of 500 V, so associated cabling, fusing, and contactors must be rated for that supply level. The controller uses the C1 + F1 combination, which includes standard vector functions and an integrated EMC filter for conducted emissions control. As a design generation 1 enclosure, its mounting dimensions and connector positions match other early RD51 frames. The enclosure format also supports consistent placement of power and control connections in cabinets that already use this platform.