Product Description:

The RD51.2-4B-018-L-A2-FW/S122 is a drive controller produced by Bosch Rexroth Indramat within the RD 500 Drive Controllers series. It is intended to regulate induction motors in industrial automation by converting fixed-frequency mains power into a variable output that matches process demands. By adjusting motor output to suit the application, it can support smoother acceleration, controlled deceleration, and stable operating speed in process equipment. This makes the controller suitable for installations such as pumps, fans, and conveyors where motor speed must vary during normal operation.

An internal brake circuit uses a built-in brake chopper to dissipate regenerated energy and protect the DC link during rapid deceleration. Speed regulation uses U/f curve control, which helps maintain stator flux across the adjustable frequency range. Thermal management relies on forced-air cooling, and the drive can deliver up to 18.5 kW of mechanical power for medium-duty motor loads. An integrated mains filter suppresses conducted noise at the input. Additional functions include externally supplied standby power and a starting lockout that prevents unintended motor energization. This arrangement is useful in applications with frequent starts, stops, and speed changes.

Input power reaches the converter through a three-phase AC supply connection, enabling operation from common plant distribution systems. The permissible line voltage is 380 to 480 V, and continuous operation is allowed as long as fluctuations remain within ±10 %. The unit is in design generation 2, so its parameter structure, option cards, and mechanical dimensions follow the second-generation RD 500 layout. The wide input range allows the controller to operate on common industrial power systems that fall within the stated tolerance.