Product Description:

The KDA 2.1-050-3-A0D-U1 is a drive controller produced by Bosch Rexroth Indramat for the KDA Spindle Drives series. Designed to regulate high-speed machine tool spindles, the unit converts a constant DC bus into a variable three-phase output that maintains torque and surface finish during metal-cutting operations. In automated cells, this controller links the motion planner to the motor shaft, allowing rapid speed changes and precise positioning required for drilling, milling, and grinding centers.

The integrated blower draws its power from a 115 V/50–60 Hz auxiliary line. This dedicated feed keeps the heat sink fan independent of the DC bus so airflow is maintained even during drive shutdowns. Under continuous duty, the power section operates from 300 VDC, and at that bus level it delivers a nominal output of 50 A, giving sufficient current margin for midsize spindle motors. Thermal performance is supported by forced cooling, which channels air through fin passages to carry heat away while the electronics remain within the specified 5 to 45 °C ambient range. These parameters allow the drive to hold base speed without derating during normal plant temperatures.

Mechanical installation is acceptable up to 1000 m above sea level, so no output adjustment is needed for standard factory elevations. The cooling hardware is a mounted heat sink blower that directs forced airflow laterally, which can simplify cabinet layout. Speed reference data enter the controller as an analog voltage, while a separate channel accepts a digital position command value; this dual-path arrangement separates velocity loops from coarse positioning commands. The KDA 2.1 variant is part of series 2 in the family, and because it does not provide a second encoder input, feedback wiring remains straightforward and cabinet space is conserved.