Product Description:

Bosch Rexroth Indramat builds the RAC 3.5-150-460-A0S-Z1-220 as part of the RAC Spindle Drive Controllers series. Classified as an AC main spindle drive controller, the unit supplies regulated three-phase power to high-speed machine tool spindles and processes speed commands from the host CNC. Series index 3 and version 5 indicate a later revision of the common control platform. It is intended for spindle applications that require stable speed under changing cutting loads and rapid command changes. In automation cells, the controller converts incoming utility power into adjustable-frequency output, allowing precise torque and speed regulation of asynchronous or synchronous spindle motors during cutting, drilling, or grinding tasks.

The power section carries a continuous rating of 150 A, enabling it to drive high-horsepower spindles without derating at full load. It accepts supply voltages of 3 x AC 400 V, 50 Hz, ±15%, or 3 x AC 460 V, so the same unit can be installed in plants with European or North American mains. Control logic and fans draw from an isolated AC 230 V / 50–60 Hz auxiliary feed, which helps keep line transients away from the processor. A built-in blower forces air across the IGBT heat sink to maintain thermal balance during prolonged acceleration cycles. The velocity loop receives its setpoint through an analog (±10 V) input, making the controller compatible with conventional CNC analog outputs and older machine interfaces.

The built-in diagnostics port is an RS-232-C serial interface, allowing parameter access and fault-history retrieval through a local connection. Field I/O wiring terminates on connector X4 with 9 poles, so signal exchange can be completed with a single plug and control wiring can stay organized inside the cabinet. A braking circuit equipped with an additional bleeder resistor absorbs regenerated energy produced by rapid deceleration events, protecting the DC bus and upstream supply. Because the hardware is specified without an additional encoder input, the drive relies on the primary spindle feedback channel already present in the standard configuration, which reduces extra wiring while preserving closed-loop accuracy.