Product Description:

The RAC 3.5-200-460-A00-W1-220 is an AC main spindle drive controller built by Bosch Rexroth Indramat for the RAC Spindle Drive Controllers series. The unit regulates torque and speed on high-power machine-tool spindles, converting line supply into a controlled three-phase output that matches dynamic machining cycles. By processing setpoints from the numerical control, the controller supplies coordinated current and voltage profiles to the spindle motor so that acceleration, deceleration, and positioning remain consistent with process demands. This supports stable spindle response during cutting, tool changes, and orientation routines.

The power section is designed for a line connection of 3 x AC 400 V, 50 Hz, +/-15% or 3 x AC 460 V, giving flexibility for European and North American plant grids. Under those supplies, it can deliver a continuous output of 200 A, which is the maximum continuous current available without thermal derating. Control electronics are energized separately through AC 230 V / 50–60 Hz, isolating low-level logic from the high-power circuits. Thermal management relies on an internal blower, so cabinet airflow does not have to pass through the heat sink. The controller accepts an analog speed reference through a ±10 V speed command, permitting straightforward coupling to standard CNC outputs.

Integration with field wiring is simplified by the X4, 9-pole interface terminal, which carries status, enable, and fault signals to the supervisory PLC. These signals support machine interlocks and drive readiness monitoring during spindle operation. The unit is revision 5. Because the unit is supplied without an additional bleeder, braking energy must be returned to the DC link or dissipated by external hardware if rapid spindle stops are required. It is also delivered without an additional encoder input, so spindle feedback is expected through the primary channel provided by the associated motor encoder.