Product Description:

The RAC 2.3-250-380-A00-W1 is an AC main spindle drive controller produced by Bosch Rexroth Indramat and assigned to the RAC Spindle Drive Controllers series. This controller regulates the torque and speed of high-performance machine tool spindles by converting supply power into a precisely metered three-phase output for induction or synchronous spindle motors. In automated machining centers, the unit serves as the central interface between the numerical control system and the spindle, enabling coordinated acceleration, deceleration, and holding behavior during cutting cycles.

It connects directly to plant power at 3 x AC 400 V, 50–60 Hz, so no step-down transformer is required. At full load the power section can conduct 250 A, providing the current headroom needed for rapid spindle acceleration under heavy cutting torque. Thermal energy generated by the power electronics is cleared by an internal blower with a built-in fan, so the cabinet does not require external coolant lines. Spindle velocity is commanded through an analog reference of analog (+/- 10 V), which simplifies connection to legacy CNC control cards while still supporting fine speed resolution. Field wiring terminates on connector X4, 9 poles, consolidating control, enable, and monitoring leads into a single pluggable interface.

Because the unit is supplied without an additional bleeder, excess regenerative energy must be absorbed by the spindle motor or an external braking module sized for the machine. The lack of an additional encoder input limits feedback handling to the primary spindle transducer, reducing complexity for systems that rely on a single position channel. The unit is hardware generation 2 and version 3, and it uses the diagnostic structure and parameter map associated with that revision level during operation.