Product Description:

The RAC 2.2-250-460-D0I-W1 is an AC main spindle drive controller produced by Bosch Rexroth Indramat and assigned to the RAC Spindle Drive Controllers series. Intended for machine tools and similar equipment, the unit converts three-phase mains power into regulated spindle current so a CNC can command both speed and torque through closed-loop control. It serves as the main power interface between the plant supply and the spindle motor during heavy cutting or grinding duty. That arrangement lets the spindle respond quickly to commanded load changes while maintaining stable operation during demanding machining cycles.

The controller accepts a supply of 3 x AC 400 V, 50 Hz, +/-15% or 3 x AC 460 V, so it can operate from common industrial distribution systems without a separate transformer. A continuous output capability of 250 A supports the acceleration of large-diameter spindles during rapid starts and speed changes. This current capacity is useful where spindle inertia is high and the control system must reach the commanded speed promptly. Thermal energy is removed by a built-in fan, so no external cabinet blower is required for the drive itself. Velocity reference data is transmitted through a 16-bit parallel digital link, giving fine speed command resolution and smooth setpoint changes. All low-voltage control wiring terminates at the X4 25-pole connector, which keeps the control interface organized.

For position feedback distribution, the drive provides an incremental encoder output, allowing a downstream CNC or PLC to monitor actual spindle angle without a separate splitter module. The unit is supplied without an additional bleeder resistor, so regenerated energy is handled internally during deceleration. It is also supplied without an additional encoder input, which means the controller is arranged for a single configured feedback channel. This layout keeps the feedback path straightforward for systems that do not require a second encoder channel. The drive is Series 2.