Product Description:

The RD51.2-4B-015-L-A2-FW is a drive controller produced by Bosch Rexroth Indramat for the RD 500 Drive Controllers series. As a converter-based unit, it modulates three-phase AC input power so that induction motors can be speed regulated in automated material handling lines, pumps, and general machinery. The product sits between the plant’s AC supply and the motor, shaping voltage and frequency according to reference commands from a PLC or a stand-alone operator panel. By varying its output electrically, the unit lets connected motors ramp smoothly during startup, normal running, and deceleration without relying on fixed-speed operation.

This controller uses U/f curve control, which keeps motor voltage proportional to frequency so magnetic flux remains stable across the speed range. This method suits applications that need reliable speed adjustment without more complex motion control. Its continuous output is rated at 15.0 kW, supporting medium-sized drives without an external step-up transformer. The input range is 380 to 480 V on a three-phase supply with a tolerance of ±10 %, allowing operation on low-voltage power systems that vary under load. The supply type is Converter 3 x AC, which means the rectifier and inverter sections are housed in one package. Thermal management is handled by forced-air cooling, and internal fans move air across the heat sinks so the unit can deliver full current during continuous operation. A built-in standby power input lets auxiliary electronics remain energized when the main bus is deactivated.

A built-in brake chopper diverts regenerative energy to a resistor, preventing DC-bus overvoltage during motor deceleration. Harmonic leakage to the plant supply is reduced by the integrated mains filter, which can lessen the need for extra line reactors in many cabinets. Startup safety is addressed through a starting lockout function that inhibits unintended motor rotation until release conditions are satisfied.