Product Description:

The KDA 2.1-050-3-L0I-U1 is a spindle drive module produced by Bosch Rexroth Indramat within the KDA Spindle Drives series. The unit forms part of a closed-loop axis package, converting digitally transmitted speed commands into controlled three-phase power that positions machine-tool spindles with high accuracy. In modern machining centers and transfer lines, it supplies and regulates current to permanent-magnet or induction spindles, coordinating with motion controllers to maintain target speed under varying mechanical load.

The power section is designed for a continuous output of 50 A, allowing high-torque spindle acceleration without saturating the drive’s internal semiconductors. It operates from a regulated 300 VDC bus supplied by the machine’s common power supply, so wiring distances to the converter must account for this fixed potential. Thermal management relies on an integrated heat sink blower that draws ambient air across the fin stack, and that fan is energized by a separate 115 V/50–60 Hz auxiliary line to isolate blower load from the DC bus. This arrangement lets the drive dissipate losses steadily during prolonged high-speed cutting.

Application limits include an ambient range of 5 to 45 °C, which aligns with typical shop-floor enclosure conditions, and installation elevations up to 1000 m, where air density still supports adequate convective flow around the blower discharge. The front panel provides an incremental encoder output, enabling the CNC control to receive real-time spindle position feedback without an external splitter, while the design omits a second encoder input to simplify channel assignment inside multi-axis cabinets. Speed references reach the unit through the SERCOS interface, permitting deterministic bus scheduling and data exchange with neighboring servo drives in the same motion network.