Product Description:

The RAC 4.1-400-460-A0I-W1 spindle drive controller is produced by Bosch Rexroth Indramat as part of the RAC Spindle Drive Controllers series. It is an AC main spindle control unit intended to modulate torque and velocity on high-power machine tool spindles, allowing coordinated cutting, drilling, or grinding operations within automated production cells. The controller serves as the power stage between the incoming supply and the spindle motor, so commanded speed changes can be translated into regulated motor output without a separate spindle control module. In CNC-controlled equipment, this supports stable spindle operation during changing process loads.

It operates from a three-phase supply of 3 x AC 400 V, 50 Hz, ±15% or 460 V lines, so the same hardware can be used in European or North American facilities without retapping transformers. Continuous output capability reaches 400 A, giving the connected spindle motor a wide constant-power zone before the inverter current limit engages. Heat from the power stage is removed by an internal blower, eliminating the need for external ductwork. Speed references are accepted through a ±10 V analog signal, which is sampled by the control electronics for linear velocity loops. Field wiring terminates on the X4, 9-pole terminal block, which groups logic, enable, and fault contacts in one connector.

For feedback distribution, the controller provides an incremental encoder output that forwards spindle position data to a CNC or synchronous axis drive. That signal can be used where the machine needs spindle position information for orientation or synchronized motion with another axis. Dynamic braking resistors can be added externally because the unit is supplied without an additional bleeder, and it also omits an additional encoder input to avoid unused channels in compact systems. The unit is Series 4 and Version 1. It is an AC main spindle drive controller intended for spindle applications that require coordinated speed control and feedback routing.