Product Description:

The KDA 2.1-150-3-L0D-W1 spindle drive is manufactured by Bosch Rexroth Indramat and belongs to the KDA Spindle Drives series. Designed as a closed-loop current controller, the unit interfaces with numerical control systems to regulate torque and speed on induction or synchronous spindle motors used in metal-cutting and other machining centers. By converting regulated DC bus energy and forwarding command data from the machine control, it supplies the motor with the phase current needed for stable high-speed operation. This control method helps the spindle respond quickly to load changes during acceleration, cutting entry, and speed transitions.

Inside the converter, the power section is rated for 150 A, allowing it to drive large spindles without saturating the output stage. The bus link accepts 300 VDC, a level typical for cabinets that place KDA modules in series with shared rectifiers. Thermal loading is managed by a mounted heatsink blower; airflow is intensified through forced cooling, preventing semiconductor derating during extended cutting cycles. That blower is fed by an auxiliary line of 220 V/50–60 Hz, so the cooling circuit can operate independently of the main power section. By moving air directly across the heat sink, the blower helps the power devices maintain consistent switching performance during sustained spindle demand.

The unit can operate from 5 to 45 °C, and installation sites may be situated up to 1000 m above sea level before additional derating rules apply. Command processing includes a digital position command value channel, while speed reference data are exchanged over the SERCOS interface, enabling coordinated multi-axis setups. The separation of command and speed-reference paths supports synchronized operation with the higher-level control system. Because there is no additional encoder socket, any second feedback device must be routed to an external controller instead of the drive.