Product Description:

The KDA 2.1-150-3-A0I-U1 is a spindle drive from the KDA Spindle Drives series manufactured by Bosch Rexroth Indramat. In machining centers or turning equipment, this drive supplies regulated three-phase power to a motor while processing an analog velocity reference from the numerical control. The onboard controller also distributes encoder information to the CNC, allowing closed-loop speed regulation that is essential for constant surface-speed cutting or rigid tapping.

The power stage is designed for a continuous output of 150 A, so matching bus cabling and protective devices must be sized for that current. Internal electronics draw energy from a 300 VDC common DC link, enabling the drive to share regenerated power with other axes on the same supply. Thermal management relies on a mounted heatsink blower; airflow is accelerated by the drive’s own fan and directed across the aluminum fin stack. This arrangement works in combination with forced cooling, which keeps semiconductor junction temperatures stable during high-duty spindle acceleration. The heatsink fan itself is fed by an auxiliary line rated at 115 V 50/60 Hz, so a single-phase service must be present inside the cabinet for blower operation.

The unit operates within an ambient envelope of 5 to 45 °C; outside this range, derating or additional cooling is required. Installation is limited to 1000 m above sea level because reduced air density diminishes convective heat removal at higher altitudes. For feedback distribution, an incremental encoder output on the front panel passes A/B/Z channels directly to the control for spindle orientation or threading functions. Speed reference enters the analog input as a ±10 V signal, identified as analog, which simplifies integration with legacy CNCs. There is no second encoder input, so applications that require dual-loop positioning must use external interface modules.