Product Description:

The RAC 3.5-200-460-D0I-W1-220 is an AC main spindle drive controller manufactured by Bosch Rexroth Indramat for the RAC Spindle Drive Controllers series. As a closed-loop power stage, it regulates spindle speed and torque in machine tools and other automated equipment that require precise rotational positioning. The unit is supplied as a standalone controller without an additional bleeder resistor and without an auxiliary encoder input, which keeps the installation focused on the main spindle control path. Its control function supports stable spindle behavior during speed changes and varying process loads.

This controller connects directly to a three-phase mains network rated at 3 × AC 400 V, 50 Hz, ±15% or 3 × AC 460 V. Under that supply, it can deliver a continuous output of 200 A to the spindle motor, enabling high-torque acceleration during cutting or drilling cycles. Thermal energy generated by those currents is removed through a built-in fan, so no external heat exchanger is required. The command interface accepts a digital 16-bit parallel speed word that the control electronics convert into firing pulses for the power semiconductors. All low-voltage signals enter through the X4, 25-pole terminal strip, which groups reference, enable, and diagnostic lines for orderly cabinet wiring.

For auxiliary circuits, the electronics draw power from a separate AC 230 V / 50-60 Hz connection that is isolated from the mains input to maintain logic integrity during line disturbances. When required, position or velocity feedback can be forwarded to external motion controllers through the built-in incremental encoder output, eliminating the need for separate splitter hardware. The product is series 3 and version 5. Because the unit does not include an additional encoder input, any multi-channel feedback arrangement must be handled by upstream control hardware.