Product Description:

The KDA 3.2-050-3-D0I-U1 is a spindle drive developed by Bosch Rexroth Indramat for the KDA Spindle Drives series. It is used in machining centers and grinding machines to regulate the torque and speed of high-frequency motor spindles used in continuous production equipment. The unit converts a constant DC bus into controlled three-phase output that follows numeric control commands.

An internal fan draws its power from a dedicated 115 V/50–60 Hz source, so the heat sink blower can continue operating even when the drive is idling. The DC bus of 300 VDC feeds the power section, and the current is limited to 50 A, which sets conductor sizing and the matching contactor rating. Thermal management relies on a mounted heat sink blower that pulls air directly across the fins, and this arrangement works with the drive’s forced cooling mode to keep semiconductor junctions within safe limits during continuous high-speed cycles. Velocity reference data arrive as a digital word, and the controller interprets a 16-bit parallel signal so numeric controls can command small speed increments with fine resolution. Because the unit omits a second encoder input, a single feedback channel from the spindle motor is used for this model in retrofit and new-build installations.

The drive can be installed up to 1000 m above sea level without derating, covering most plant elevations. Reliable operation is specified between 5 to 45 °C, so cabinet ventilation or air conditioning must be planned if ambient conditions exceed that range. For position-synchronous spindle functions, an auxiliary interface provides an incremental encoder output that retransmits tachometer pulses to the CNC and simplifies wiring in multi-axis systems. The unit is in Series 3 and Version 2 within the KDA spindle drive range used in automated machine tools.