Product Description:

The RAC 2.3-250-380-A00-Z1 is an AC main spindle drive controller produced by Bosch Rexroth Indramat and assigned to the RAC Spindle Drive Controllers series. The unit regulates torque and speed on high-power machine-tool spindles by converting three-phase mains power into a controlled output that follows an external velocity reference. Through this function, it bridges CNC commands and the electromechanical spindle, delivering closed-loop control suited to precision milling, turning, and grinding applications. That makes it suitable for spindle applications that require stable speed regulation and quick response during cutting operations. It is dimensioned for cabinet installation and interfaces directly with supply modules and feedback devices, forming a coordinated axis within modular automation architectures.

The controller accepts a three-phase supply of 3 x AC 400 V, 50–60 Hz, so cabinet wiring can tie into standard industrial mains without an intermediate transformer. With a continuous output of 250 A, the power stage supports high-torque spindle motors that demand large startup currents. Heat produced by the IGBTs and bus bleeder is removed by an internal blower, allowing operation without external ducting. Spindle speed is commanded through a differential analog reference of ±10 V, enabling direct connection to common CNC velocity outputs. Field signals and low-level logic are routed through the X4, 9-pole terminal, which consolidates enable, fault reset, and monitor points into one connector for simpler panel wiring.

Energy returned during rapid deceleration is dissipated locally because the drive is supplied with an additional bleeder, reducing stress on the DC bus capacitors. Position synchronization hardware is minimized since the unit operates without an additional encoder input; the primary encoder channel from the spindle motor is handled through the axis feedback interface already on the base board. This arrangement keeps the control hardware focused on the primary spindle feedback path and avoids extra connection points on the controller. Within the product line, it is identified as Series 2 and Version 3.