Product Description:

The Bosch Rexroth Indramat RAC 3.5-150-460-LP0-Z1-220 is an AC main spindle drive controller in the RAC Spindle Drive Controllers series. It is designed to regulate high-power machine-tool spindles by converting three-phase mains power into precisely modulated motor current. This allows cutting, grinding, and boring operations to maintain steady spindle speed under changing mechanical load. The controller also works with digital motion systems to support coordinated machining sequences across the spindle and feed axes, which is important where speed stability affects surface finish and process consistency.

Its rated output handles 150 A, allowing the drive to energize large-frame synchronous or induction spindles without early current limiting. The power stage accepts 50 Hz supplies at either 3 x AC 400 V ±15% or 3 x AC 460 V, which supports use on common industrial mains. Low-power electronics are supplied separately by AC 230 V / 50–60 Hz, keeping control power independent from the high-energy bus section. An internal blower moves air across the heat sink, and an additional bleeder dissipates regenerative energy returned during spindle deceleration. The controller is series 3 within the product family, and this arrangement separates logic supply from the main power section for stable operation.

Command and feedback channels are fully digital. Speed reference signals arrive through the SERCOS interface, while the drive reads actual position from a high-resolution INDRAMAT encoder for closed-loop spindle control. Fiber-optic communication on X4 optical waveguides helps isolate signaling from electrical noise commonly present in spindle enclosures. An additional encoder input allows secondary feedback when direct spindle position verification is required. The controller is version 5 and supports parameter groups for this dual-loop arrangement while providing detailed status reporting to the higher-level control.