Product Description:

The KDA 2.1-050-3-D0D-U1 is a spindle drive module engineered by Bosch Rexroth Indramat within the KDA Spindle Drives series. It converts a stabilized DC bus into variable-frequency power for machine-tool spindles, enabling closed-loop speed control in automated machining centers. In a machine tool, it serves as the power stage between the DC supply and the spindle motor so commanded speed changes can be applied quickly and with repeatable control. The module is intended for CNC-controlled spindle applications that require stable speed regulation during changing cutting loads.

Internally, the drive is powered from a DC bus of 300 VDC, and its output section is rated for a continuous phase current of 50 A. Thermal management relies on a mounted heat sink blower, and the airflow method uses forced cooling. To run that fan, the housing provides an auxiliary AC feed of 115 V/50–60 Hz, eliminating the need for an external low-voltage supply. These operating values describe the electrical input and cooling support used during sustained spindle operation. The drive does not provide a second encoder input, so feedback wiring is limited to the primary spindle encoder supplied by the machine builder.

Command data reach the Series 2 controller entirely in digital form. A host CNC issues speed references through a 16-bit digital parallel interface, while position slots are updated through the digital position command value interface; the separate channels keep velocity loops and orientation moves independent. Using separate command channels also allows normal speed control and spindle orientation functions to be handled without changing the basic connection scheme. Reliable operation is maintained between 5 to 45 °C, and the unit can be installed at elevations up to 1000 m above sea level without output derating. When these ambient or altitude limits are approached, cabinet airflow or spindle load must be adjusted so the blower can maintain safe operating temperature.