Product Description:

The RAC 3.5-100-460-API-Z1-220 is an AC main spindle drive controller produced by Bosch Rexroth Indramat for the RAC Spindle Drive Controllers series. Designed as the power and regulation core for machine-tool spindles up to 100 A, it links a three-phase supply to a servo spindle fitted with a high-resolution INDRAMAT encoder, allowing precise speed regulation across tapping, milling, and grinding cycles. By converting an analog velocity reference into controlled motor current, the unit maintains constant surface speed, shortens acceleration time, and improves dimensional accuracy in automated lines.

To match global supply networks, the power section accepts 3 × AC 400 V at 50 Hz with ±15 % tolerance or 3 × AC 460 V. At full load, it delivers 100 A, giving the drive the current capacity needed for heavy roughing passes. Control electronics are energized separately from an AC 230 V / 50–60 Hz service outlet so the logic remains active during mains fluctuations. Heat is extracted by a built-in blower, eliminating the need for cabinet ducting. An integrated regeneration path equipped with an additional bleeder resists overvoltage when the spindle brakes hard, converting excess kinetic energy into heat and preventing DC-bus trips during rapid deceleration.

Command and feedback routing is arranged through the control interface. Speed reference enters as an analog (±10 V) differential signal, while position data can be returned through an additional encoder input for spindle feedback that supports the fitted high-resolution encoder. Real-time spindle angle is also broadcast through an incremental encoder output, simplifying synchronous tapping or C-axis interpolation. All low-level wiring is brought to the X4, 9 poles terminal strip. The unit is identified as hardware series 3 and version 5 for compatibility with associated RAC inverters and diagnostic tools.