Product Description:

The RAC 2.3-250-460-LP0-Z1 is an AC main spindle drive controller produced by Bosch Rexroth Indramat within the RAC Spindle Drive Controllers series. It governs high-power machine-tool spindles by converting three-phase mains energy into regulated motor output while exchanging velocity commands with higher-level CNC or PLC hardware. In automated machining systems, it serves as the power stage between the plant supply and the spindle motor, allowing the motion controller to request speed changes without direct handling of motor current. Its control platform supports applications that require consistent torque, quick acceleration, and precise directional reversals during machining. This makes the unit suitable for spindles that must hold stable speed through cutting, tapping, and rapid changes in load.

This controller delivers up to 250 A of output current, enabling it to energize large-frame spindle motors without external boosters. It accepts supply lines at 3 x AC 400 V on 50 Hz mains with a +/-15% input tolerance, as well as 3 x AC 460 V, which supports use in facilities with different standard utility voltages. Thermal management is handled by an internal blower that moves cabinet air across the heat sink, so separate ducting is not required. Rotational speed references arrive through the SERCOS interface, and the fiber-optic link helps the drive exchange commands with low susceptibility to electrical noise in busy control cabinets.

Energy returned from rapid deceleration is routed through an additional bleeder, which helps prevent DC-bus overvoltage during aggressive spindle slowdown. A dedicated additional encoder input accepts spindle feedback when secondary position data are needed for orientation or threading cycles. Communication fibers connect at the X4 optical waveguides terminal, keeping the signal path separate from high-power copper wiring inside the cabinet. Mechanical accuracy is supported by a high-resolution INDRAMAT encoder, which helps the controller maintain smooth speed regulation at low and high operating speeds. This feedback arrangement also supports precise spindle orientation before processes that depend on repeatable angular positioning.