Product Description:

The RAC 2.3-250-380-AP0-W1 is a Bosch Rexroth Indramat controller from the RAC Spindle Drive Controllers series. Classified as an AC main spindle drive controller, it converts fixed mains power into a regulated three-phase output that follows motion commands from a numerical control. The unit governs spindle acceleration, steady-state speed, and braking so machining operations can maintain dimensional accuracy and surface finish. Its design combines power electronics, control logic, and closed-loop spindle regulation in one chassis. It is suited for machine tools where spindle speed must remain stable during cutting, threading, and other synchronized operations.

For power interfacing, the drive requires a 3 x AC 400 V, 50–60 Hz supply and can deliver up to 250 A of output current to the spindle motor. Heat generated by the power section is removed by an internal blower, which supports operation in a sealed cabinet without external ducting. Speed reference is provided as an Analog (±10 V) signal, allowing direct connection to many CNC control platforms. Command and auxiliary wiring terminate at the X4 9-pole terminal, so low-level connections are grouped at a single plug. Separating the power path from the command terminal area helps keep cabinet wiring orderly.

For precise spindle control, the controller accepts feedback from a high-resolution Indramat encoder. The internal processor also supports an additional encoder input for spindle feedback when dual-loop operation is needed. The unit is supplied without an additional bleeder, so braking energy must be absorbed by the motor or by an external resistor bank matched to the duty cycle. This arrangement supports spindle functions that rely on synchronized feedback signals, including orientation and rigid tapping. The controller is Version 3.