Product Description:

The KDA 2.1-100-3-D00-U1 is a spindle drive module built by Bosch Rexroth Indramat within the KDA Spindle Drives series. Designed for closed-loop control of high-speed machine-tool spindles, the unit converts regulated DC bus power into precisely metered three-phase output for induction or synchronous motors. In an automation cell, it forms the axis-specific power stage that follows numerical control commands and monitors feedback to maintain constant spindle velocity and torque. Because it belongs to the second design generation, it includes diagnostic LEDs and standardized terminal strips that simplify cabinet wiring without changing the base dimensions used by earlier KDA units.

Internally, the drive is powered from a shared DC link held at 300 VDC. This potential is switched by IGBT modules that can deliver a continuous output of 100 A to the connected motor. Control electronics receive the commanded speed through a 16-bit parallel digital interface, so numerical controllers can set exact rotational rates without analog drift. Thermal energy from the semiconductors is removed by a heat sink that is swept by air drawn through a blower supplied from an auxiliary line rated at 115 V, 50–60 Hz. The airflow path uses forced cooling, allowing high current density while keeping component temperatures within safe limits during prolonged roughing cycles.

In service, the module must be installed where ambient air remains between 5 to 45 °C, because operation outside this band can trigger overtemperature protection. Cabinet placement is also restricted to elevations not exceeding 1000 m above sea level so that cooling airflow retains its calculated mass flow. The assembly includes a mounted heat sink blower, eliminating the need for separate ducting and keeping overall depth unchanged. The unit has no additional interface option, and the secondary encoder input is intentionally omitted when a single-channel spindle encoder is adequate.