Product Description:

The RAC 2.2-250-380-AY0-W1 is an AC main spindle drive controller produced by Bosch Rexroth Indramat for the RAC Spindle Drive Controllers series. Designed to regulate the speed and torque of machine-tool spindles, it interfaces with CNC or PLC hardware to maintain precise rotational profiles during cutting or forming operations. Its electrical section manages the power stages while the control section executes command and feedback loops necessary for industrial automation.

This version 2 unit draws its supply from a three-phase 3 x AC 400 V, 50-60 Hz network and can deliver up to 250 A to the spindle motor. Velocity reference reaches the controller through a differential analog input that accepts ±10 V signals, allowing straightforward linkage with common motion processors. Thermal management relies on an internal blower, so cabinet airflow need not be supplemented by external ducts. Field wiring for control inputs and auxiliary feedback connects to the front-panel X4 9-pole interface; this terminal layout streamlines encoder, enable, and status circuits without additional breakout boards.

The control logic is prepared for an integrated measuring system because an additional encoder and synchronous input are available alongside the primary channel. The spindle position is read by an incremental encoder (JL), and the controller converts the pulse train into a lead spindle feedback value used for closed-loop speed stabilization. This feedback path lets the controller correct speed changes quickly when cutting load varies during acceleration, deceleration, or steady spindle operation. Energy returned during rapid deceleration is dissipated internally, and the unit comes without an additional bleeder, so external resistors are unnecessary.