Product Description:

The KDA 3.2-100-3-API-U1 spindle drive is produced by Bosch Rexroth Indramat and belongs to the KDA Spindle Drives series. As a closed-loop power module, it supplies controlled three-phase energy to high-speed machine-tool spindles, translating velocity references from the motion controller into precise motor currents. Series 3, Version 2 supports a second encoder channel for spindle position monitoring, giving the unit a role in machining centers that require synchronized cutting, tapping, or C-axis interpolation. This arrangement also allows the control system to track spindle motion more closely during operations that depend on accurate angular coordination.

Internally, the drive is powered from a DC bus of 300 VDC, allowing the inverter stage to modulate three-phase output without an internal rectifier. Under continuous operation, it delivers a rated line current of 100 A, so cable sizing and protective devices must accommodate this load. The heat sink blower is fed from an auxiliary single-phase source of 115 V at 50/60 Hz, which keeps the cooling circuit separate from the main DC supply. Spindle velocity is commanded through an analog reference that can be ±10 V or 0–10 V, and motion status is exported through an incremental encoder output that reproduces spindle feedback for downstream numerical control modules. A dedicated secondary encoder input can also accept additional motor or spindle feedback for applications that need expanded monitoring.

The thermal design relies on a mounted heat sink blower that pulls air across the fin stack. This arrangement uses forced cooling to keep semiconductor junction temperatures within acceptable limits during sustained high-current cycles. Reliable performance is specified for ambient temperatures from 5 °C to 45 °C, so the surrounding air must stay within that range during operation. Installation is permitted up to 1000 m above sea level without derating, which supports use in most factory locations. The cooling layout helps the drive maintain steady operation during long machining cycles, and the separate blower supply supports stable airflow whenever the unit is in service.