Product Description:

The RD51.1-4B-018-L-DF-FW drive controller is manufactured by Bosch Rexroth Indramat as part of the RD 500 Drive Controllers series. This three-phase converter conditions incoming power and issues controlled output pulses for automation tasks such as variable-speed pumps, fans, and conveyor drives. Within an installation, it forms the link between a higher-level PLC and the motor, translating setpoints into motor voltage and frequency that keep process variables on target even under fluctuating load. It is suited to applications that need repeatable speed control during changing operating conditions.

The controller delivers a rated shaft supply of 18.5 kW, giving it enough capacity for mid-range production motors. It operates on line voltages from 380 to 480 V and uses a three-phase AC converter topology, so it connects directly to a standard industrial power bus. Input variations are tolerated within ±10%, which helps maintain output accuracy without external stabilizers. Thermal energy is removed through forced-air cooling, and fans move cabinet air across the heat sink to support compact panel installation. The unit is design 1, indicating the first mechanical revision.

Dynamic braking energy is handled internally by a built-in brake chopper, eliminating the need for an external resistor switch. Speed regulation follows a U/f curve control method that matches voltage to frequency for stable magnetization across the full speed range. Line-side disturbances are attenuated by the integrated line filter, which helps improve EMC behavior inside crowded panels. The control terminals include a NAMUR terminal strip with 24 V standby power, so status sensors can remain active during a main power loss. A separate channel provides feedback of current filter levels, identified as U6, V6, and W6, for diagnostic trend monitoring.