Product Description:

The KDA 2.1-050-300-AP0-U1-115 is a dedicated power module produced by Bosch Rexroth Indramat for the KDA Spindle Drives series. The unit forms part of a servo spindle loop, converting intermediate-circuit energy into three-phase output that maintains commanded speed and torque on high-precision machine-tool spindles. By integrating current sensors and fault monitoring, it enables CNC controllers to regulate cutting processes while protecting the attached motor and cabling from overload conditions during both roughing and finishing passes. This arrangement helps the spindle respond consistently when cutting forces change during acceleration, tool engagement, or sustained material removal.

The drive is engineered for a continuous output of 50 A, so the connected spindle can sustain heavy chip removal without derating. It links to the supply bus at 300 VDC, allowing several axes to share one rectifier cabinet and simplifying energy balancing through regenerative braking. Thermal management relies on forced cooling; an external blower moves cabinet air across the heat sink to keep semiconductor junctions within safe limits. Electronic components remain operational between 5 to 45 °C, which covers typical industrial cabinet conditions when ventilation is provided. Mechanical design permits installation up to 1000 m above sea level, so altitude-related derating is unnecessary for most plant locations. Stable cabinet airflow also helps the module maintain consistent switching behavior during long machining cycles.

Within Series 2 units, the layout separates the insulated-gate transistor power stage from the low-voltage control logic, which helps keep signal handling isolated from the DC bus. Adequate clearance behind the cabinet preserves the forced-ventilation airflow path; blockage can reduce cooling performance and may trigger an overtemperature trip before the spindle reaches full load. The separated layout also makes tracing low-voltage signals more straightforward during inspection and electrical testing. This arrangement supports stable spindle operation when the drive is used for continuous speed regulation under varying load conditions.