Product Description:

The RAC 3.1-100-460-A00-W1-220 is an AC main spindle drive controller manufactured by Bosch Rexroth Indramat for the RAC Spindle Drive Controllers series. Designed for closed-loop speed regulation of induction or synchronous spindle motors, the device converts fixed-frequency utility power into a modulated three-phase output for high-speed machining. Within an automated production cell, it forms the interface between the plant power source and the rotating spindle shaft, coordinating acceleration, braking, and steady-state operation while supervising thermal and electrical limits. This operating role is suited to machine tools that need stable spindle speed during changing cutting loads.

It accepts a three-phase supply of 3 x AC 400 V, 50 Hz, ±15% or 3 x AC 460 V and can deliver up to 100 A to the spindle motor. Control electronics are powered separately from an AC 230 V / 50-60 Hz supply. Separate control power lets the command section remain energized during spindle power transitions, which helps preserve diagnostic visibility. Velocity reference is received through an analog ±10 V input, allowing direct connection to CNC command channels. Status and fault signals are carried through the 9-pole X4 connector. Heat from the power section is removed by an internal blower built into the chassis, so extra ducting is not required.

The drive is supplied without an additional bleeder, so regenerative energy during braking is handled by its internal dissipation path. It is also supplied without an additional encoder input, which means the primary motor encoder sends position data to the motion controller rather than to the drive. The unit is Version 1 and belongs to Series 3. This layout suits machine architectures that keep feedback handling and higher-level spindle supervision outside the power stage.