Product Description:

The RAC 3.5-100-460-L00-W1-220 is an AC main spindle drive controller manufactured by Bosch Rexroth Indramat and assigned to the RAC Spindle Drive Controllers series. It is engineered to govern high-speed machine-tool spindles, converting three-phase mains power into precisely regulated output that follows digital speed commands from the motion control system. By integrating the power stage, control electronics, and cooling fan in a single housing, the unit provides a compact means of maintaining spindle torque and velocity during cutting, drilling, or grinding operations.

This controller draws a continuous phase current of 100 A, establishing its maximum thermal load when paired with compatible spindle motors. Two input voltage ranges are accepted: 3 × AC 400 V at 50 Hz with a ±15% tolerance, or 3 × AC 460 V for installations on higher-voltage networks. Internal logic and I/O are powered separately from an AC 230 V supply at 50–60 Hz, isolating sensitive circuits from mains disturbances. Thermal management relies on an internal blower that moves air through the heat sink to keep semiconductor temperatures within safe operating limits, eliminating the need for external ducting. This arrangement supports stable spindle operation during long machining passes and repeated speed changes.

Speed references are exchanged across the drive’s fiber-optic channel using the SERCOS interface. Diagnostic and parameter data reach the controller through connector X4, which carries the optical waveguides. The product is Series 3 and Version 5. The design omits an additional bleeder resistor, so regenerated energy must be handled by the standard braking circuit or external systems, and it is supplied without an additional encoder input, relying on the primary spindle feedback already present in the machine architecture.