Product Description:

Bosch Rexroth Indramat manufactures the KDA 2.1-100-3-A0I-U1 spindle drive in the KDA Spindle Drives series. The module acts as the interface between a numerical controller and a synchronous or induction spindle motor, shaping current and voltage so commanded speeds are reached with tight deviation. Its integrated blower, DC link, and logic sections make it suitable for compact control cabinets where rapid acceleration, constant surface speed machining, and reliable spindle braking are required. This arrangement allows the drive to support both speed regulation and braking behavior within a single cabinet-mounted unit.

The power section is rated for a continuous output of 100 A, giving the connected motor strong starting torque during thread cutting and high-inertia starts. A shared DC bus supplies the drive with 300 VDC, allowing multiple axes to regenerate energy into the same link. The heat sink blower is powered by a dedicated 115 V/50–60 Hz source so thermal loading is removed independently of the DC link. Because cooling air is forced directly over the fins, the drive uses forced cooling, which helps maintain stable semiconductor temperatures during prolonged low-speed operation. Speed reference data enter the control electronics as an analog voltage, supporting integration with legacy CNCs that output ±10 V commands while allowing smooth spindle response during setpoint changes.

The unit operates in ambient temperatures from 5 to 45 °C without derating, and installation is permitted up to 1000 m above sea level before additional cooling becomes necessary. For feedback distribution, the front panel provides an incremental encoder output that mirrors the motor tachometer to downstream measuring devices. There is no second encoder input, so the feedback layout stays focused on a single primary channel. This arrangement suits spindle systems that use one motor feedback device while forwarding duplicated pulse information to external monitoring or display equipment. The simplified signal path is useful in machines that do not require a separate secondary encoder channel.