Product Description:

The KDA 3.1-150-3-AQI-U1 spindle drive is manufactured by Bosch Rexroth Indramat for the KDA Spindle Drives series. Designed for machine tools and production centers, the drive transforms a constant DC supply into variable three-phase output that regulates spindle torque and speed. By combining current and speed control in the same housing, the module reduces cabinet wiring and shortens control loops. Its role is to supply controlled power to the spindle motor so commanded speed changes remain stable during machining.

It operates from a DC link of 300 VDC supplied by an external source and converts that energy into sinusoidal armature power. The power stage is rated for a continuous output of 150 A, enabling the unit to drive large-frame asynchronous or synchronous spindle motors without sacrificing dynamic response. For thermal control, the housing uses a heat sink-mounted blower powered by an auxiliary supply of 115 V/50-60 Hz. The blower forces air across the fin stack so semiconductor junction temperatures remain within safe limits during sustained duty. Position and velocity data can be forwarded to external CNC or PLC hardware through an incremental encoder output, allowing higher-level control loops to be closed outside the drive while current regulation remains internal.

Revision 3 adds operating limits for ambient conditions and site elevation. The forced cooling path allows operation in cabinet ambient temperatures from 5 to 45 °C without derating. Altitude capability reaches 1000 m above sea level; above that height, lower air density reduces heat transfer and the continuous current must be lowered. Speed references are accepted as an analog command value, which simplifies use with conventional CNC controllers that provide a ±10 V spindle reference. This format also suits retrofit applications where digital spindle commands are not used.