Product Description:

Bosch Rexroth Indramat designs the RAC 2.2-250-460-LP0-W1, an AC main spindle drive controller in the RAC Spindle Drive Controllers series. This unit regulates the power and speed of spindle motors in machining centers and other automated tooling stations. By converting three-phase mains power into controlled output and coordinated velocity commands, it serves as the link between the machine control layer and the mechanical spindle during cutting, drilling, and grinding operations. It is intended for high-performance spindle applications that require stable rotation and consistent torque response while cutting loads change.

The controller accepts a rated connection voltage of 3 x AC 400 V, 50 Hz, ±15% or 3 x AC 460 V, allowing operation on common industrial mains in different regions. At a continuous output of 250 A, it can energize large spindle windings while still responding to dynamic load changes commanded over the SERCOS interface. An internal blower removes heat from the power section, so no external air channels are required inside the cabinet. Command and diagnostic fibers connect through the X4 optical waveguides terminal, which helps isolate the drive electronics from electrical noise and supports fast data exchange with the CNC control.

Axis feedback is provided by a high-resolution INDRAMAT encoder that gives the drive precise position data for spindle control. An additional encoder input is available when the machine uses a secondary measurement system, so external position signals can be processed alongside the main feedback channel. The unit is supplied without an additional bleeder, so regenerative energy from rapid deceleration must be handled by the line supply unit or an external dumping resistor. The controller is built as version 2, which identifies this product revision within the series.