Product Description:

The KDA 2.1-100-3-AQI-W1 is a spindle drive controller produced by Bosch Rexroth Indramat for the KDA Spindle Drives series. The unit draws regulated DC power from an Indramat supply module and converts it into three-phase output for high-speed machine-tool spindles. By monitoring current and speed feedback, it helps maintain stable torque during cutting, drilling, and grinding cycles. Integrated diagnostic LEDs and an incremental encoder relay allow the host CNC to observe operating status without opening the cabinet. This arrangement supports spindle applications that require consistent speed control during changing load conditions.

Internally, the drive is linked to a common DC bus at 300 VDC and can deliver up to 100 A of continuous armature current to the spindle motor. The control board accepts a 220 V/50–60 Hz auxiliary supply that powers the blower and supports the drive electronics tied to the speed-control circuit. Cooling is provided by a mounted heat sink blower that operates with forced cooling, helping keep the power semiconductors within a safe operating temperature range during sustained high-current duty. An incremental encoder output is routed to a dedicated terminal block so the CNC can read actual spindle speed directly from the drive. This direct feedback path supports accurate speed supervision during continuous machining cycles.

The drive is intended for ambient conditions from 5 °C to 45 °C, and installation is permissible up to 1000 m above sea level. The velocity loop uses an analog command signal, which the control circuitry filters before generating PWM patterns for the motor. The product is Version 2 in the KDA family. Filtering the command input helps the drive respond smoothly to changing spindle demands while reducing the effect of electrical noise on speed regulation.