Product Description:

Bosch Rexroth Indramat developed the KDA 3.3-150-3-D00-U1 for the KDA Spindle Drives series. The unit functions as the power stage that converts a shared DC bus into a controlled three-phase output, letting CNC controllers command high-speed spindle motors in milling, turning, or grinding cells. By interpreting digital speed references and supervising current, temperature, and position feedback, the drive unit maintains accurate spindle velocity during rapid changes in load or direction, supporting precise material removal in automated machine tools and similar equipment.

The power section is fed from a 300 VDC link, and its transistor bridge is rated for a continuous output of 150 A, enabling aggressive acceleration of large tool holders without saturation. Cooling is provided by a centrifugal blower supplied at 115 V/50–60 Hz, so the control cabinet does not have to provide low-voltage auxiliaries. The permitted ambient operating window extends from 5 to 45 °C; within this range, the drive can operate without derating. Installation is specified up to 1000 m above sea level, beyond which reduced air density limits thermal dissipation. Command values arrive through a digital 16-bit parallel channel, giving fine speed resolution and eliminating analog offset errors.

Heat is extracted through a mounted heat sink blower that draws air across fins bonded to the power module, and this hardware works with the drive’s forced cooling mode to keep semiconductor junctions below their limit during continuous-duty operation. The Series 3 control platform is fixed, so expansion paths are limited. The unit has no additional interface option, so fieldbus or analog add-on cards cannot be installed. A secondary encoder port is also absent, which simplifies wiring and keeps the drive dedicated to the primary spindle feedback channel.