Product Description:

Bosch Rexroth Indramat builds the KDA 3.2-100-3-LPI-U1 for machine-tool and high-speed machining centers that require precise spindle regulation. The unit belongs to the KDA Spindle Drives series, version 3.2, and functions as a closed-loop power stage between the CNC controller and the motor. By converting the shared DC bus energy into three-phase output and supervising feedback channels, it maintains commanded spindle speed while protecting the motor against overload and supply disturbances.

The drive delivers a continuous output of 100 A, giving ample current headroom for rapid acceleration of large spindle masses. Its power section is energized from a common bus at 300 VDC, allowing multiple axes to share the same supply and regeneration circuitry. Thermal management is handled by a heat sink assembly served by a blower that runs on 115 V/50–60 Hz; this external source keeps cooling independent of the DC link so airflow is present as soon as the cabinet is powered. Internal sensors trigger the blower automatically, and the cooling path uses forced cooling to move heat away from semiconductor junctions. For motion coordination, the servo control board provides an incremental encoder output so a downstream PLC or master drive can read real-time spindle position without additional splitter hardware.

A digital speed word is transmitted through the SERCOS interface, allowing the controller to set velocity, orientation, and override values with 32-bit resolution. Reliable operation is specified within an ambient range of 5 to 45 °C, ensuring full duty in most enclosed cabinets. Installation sites can reach 1000 m altitude before derating is considered, matching standard factory elevations. For applications that need synchronized tool and workpiece feedback, a second encoder input accepts either spindle-mounted sensors or an additional motor transducer, enabling dual-loop control strategies that improve contour accuracy and surface finish.