Product Description:

The RAC 3.5-100-460-A0S-W1-220 is an AC main spindle drive controller manufactured by Bosch Rexroth Indramat for the RAC Spindle Drive Controllers series. It converts analog speed references into controlled three-phase output for motorized spindles used in machining centers, grinders, and similar equipment. Its control section is intended for machine tools that require stable spindle behavior across varying load conditions. Classified as Version 5 of the Series 3 platform, the unit combines power electronics and control logic to minimize panel space while supporting tight velocity regulation throughout the spindle’s working range.

The power stage is designed to run directly from factory mains of 3 x AC 400 V at 50 Hz, with a tolerance of up to ±15%, or from an alternative supply of 3 x AC 460 V used in North American installations. Continuous output capability is rated at 100 A, so the controller can support sustained high-torque spindle operation without early current limiting under normal conditions. Control electronics are fed by an auxiliary line of AC 230 V, and the board logic remains synchronized across grids that operate at 50–60 Hz. The separate auxiliary supply keeps control functions available independently of the main power stage requirements.

No external bleeder or secondary encoder channel is fitted, which reduces wiring complexity. Process feedback and diagnostics move over an RS 232-C serial interface, while velocity demand enters as a differential analog (+/- 10 V) signal. The command and diagnostic channels support routine monitoring without adding a separate external interface card. All low-level I/O is grouped on the keyed X4, 9-pole terminal block, which keeps control connections organized within the drive. An internal blower removes heat from the heat sink so the controller can maintain rated current in enclosed mounting positions without cabinet air exchangers.