Product Description:

The RAC 3.5-200-460-D0D-W1-220 is an AC main spindle drive controller produced by Bosch Rexroth Indramat for the RAC Spindle Drive Controllers series. It regulates high-speed spindle motors in machining centers and turning machines by converting incoming three-phase supply power into controlled current that follows numerical control commands. This allows the drive to support the torque and speed changes needed for drilling, milling, and grinding operations in automated production equipment. It is used where spindle speed must respond quickly to programmed changes while maintaining controlled torque through varying cut conditions.

Power is delivered to the controller through a 3-phase 400/460 V AC mains connection, and the power section can conduct up to 200 A without derating. Its control electronics draw their supply from 230 V AC at 50–60 Hz, keeping low-level logic separate from the high-energy bus. Heat produced by the switching devices is removed by an internal blower, eliminating the need for external ducts, and field wiring for command and monitor lines is landed on the X4 25-pole terminal block, which keeps those connections grouped at one interface. The design has no additional bleeder circuitry, so braking energy is absorbed by the integral transistor-resistor assembly, and it also has no additional encoder input, so feedback is taken from the primary spindle sensor used by the machine control.

Command data reaches the drive over a 16-bit position word, and speed demand is transmitted as a separate 16-bit speed word; both channels use the parallel protocol assigned to the controller. The drive is version 5 and belongs to series 3. This digital structure reduces analog drift and lets the internal control loop work directly with high-resolution command values during acceleration ramps, steady-speed operation, and constant-surface-speed control.