Product Description:

The KDA 3.1-100-3-LPS-U1 spindle drive is produced by Bosch Rexroth Indramat as part of the KDA Spindle Drives series. It is an inverter module that converts the shared DC bus energy of a Rexroth cabinet system into three-phase output for high-speed machine-tool spindles. Revision 3 hardware with the LPS option adds dedicated logic for position-synchronous commands, allowing a CNC controller to impose exact speed and torque profiles during roughing, finishing, or tapping cycles.

This drive draws its power from a link voltage of 300 VDC and can continuously deliver up to 100 A of output current to the connected spindle motor. Thermal management is handled by an integral blower whose motor is supplied by a separate 115 V/50-60 Hz source, which helps isolate the fan circuit from bus disturbances during startup surges. Airflow is forced directly across the external heat-sink fins, a method identified as forced cooling, and it keeps semiconductor temperatures within safe limits under full load. The velocity loop setpoint is received over a real-time SERCOS interface, allowing the drive to synchronize spindle speed with feed axes for rigid tapping or spindle-orient functions without additional analog wiring.

The unit operates in ambient temperatures from 5 to 45 °C, supporting typical shop-floor conditions without derating. Installation is permitted up to 1000 m above sea level, which covers most manufacturing facilities without special cooling provisions. A built-in serial interface (RS-232C) provides parameter backup and diagnostic access outside the SERCOS network, which is useful when direct local communication is needed. Cooling air is delivered by the externally mounted blower assembly identified as a mounted heat-sink blower, so the cooling section remains separate from the main power conversion path.