Product Description:

The RD51.1-4N-055-L-D1-FW drive controller is produced by Bosch Rexroth Indramat within the RD 500 Drive Controllers series. Designed for cabinet mounting in automation cells, it modulates the voltage and frequency supplied to standard induction motors so that conveyors, pumps, or fans can be matched to process demand. By linking motor speed to reference commands from a PLC, the device supports energy savings and precise motion coordination on three-phase production lines. In multi-axis installations, it interfaces with standard field wiring and fault signaling circuits so operating status can be monitored by the control system.

It accepts a three-phase supply classified as a 3 x AC converter and operates across a line window of 380 to 480 V with a tolerance of ±10 %. The controller delivers up to 55 kW of mechanical power, which suits medium-sized production drives that require variable-speed operation. Motor flux is regulated through U/f curve control, which keeps the volts-per-hertz ratio constant so torque remains stable from standstill to base speed. This operating range is useful when selecting upstream protection, supply conductors, and associated thermal devices for the connected motor system.

Heat produced by the switching elements is removed by forced-air cooling, so cabinet temperatures can remain within component limits at full load. The unit is supplied without a built-in brake chopper, so braking energy from rapid deceleration must be handled by external hardware. An integrated mains filter helps reduce conducted interference on the incoming power lines. For control wiring, the front panel provides a NAMUR terminal strip and a 24 V standby input, which allows digital signals to remain active during a main power interruption and supports continuity of external status signals.