Product Description:

The RAC 4.1-400-460-AP0-W1 is an AC main spindle drive controller produced by Bosch Rexroth Indramat within the RAC Spindle Drive Controllers series. Designed for three-phase mains at 400 V or 460 V, it governs the torque and speed of high-performance machine tool spindles through analog velocity commands. As the central component in an automation axis, the unit translates reference voltages into controlled stator currents while monitoring feedback from a high-resolution encoder. It is intended for spindle applications that require accurate speed regulation and fast response during changing process conditions.

The rated connection is 3 x AC 400 V, 50 Hz, +/-15%, or 3 x AC 460 V, which allows operation on European or North American plant power without external transformers. The controller can supply up to 400 A of continuous output current, supporting large spindle loads during sustained operation. Internal heat is removed by a built-in blower, so the drive can manage thermal buildup during extended running periods. Command inputs are accepted through an analog (±10 V) input, allowing the control system to send a precise speed reference. The analog reference format also supports straightforward integration with control hardware that uses voltage-based speed commands. All power and signal conductors terminate at the X4 9-pole connector, which keeps the interface consolidated at one connection point.

For position verification, the drive includes an additional spindle feedback encoder input. This secondary channel supports a high-resolution Indramat encoder, helping the control loop maintain accurate spindle behavior during acceleration and load changes. That feedback path is useful when the spindle must hold tight speed control or support synchronized motion functions. The model is supplied without an additional bleeder, so regenerative energy is handled through the DC link and motor. The unit is part of Series 4 and is Version 1.