Product Description:

The RAC 2.2-250-380-L00-Z1 is an AC main spindle drive controller produced by Bosch Rexroth Indramat and supplied within the RAC Spindle Drive Controllers series. This controller manages the torque and rotational speed of induction or synchronous spindle motors in automated machining centers and other precision equipment. It converts incoming three-phase mains power into a regulated output that follows real-time setpoints from upper-level motion controllers. That behavior supports stable spindle operation during cutting, drilling, and other speed-controlled machine processes. It is intended for use in machine tools where repeatable spindle response is needed for accurate process results.

For power acceptance, the unit is wired to a supply of 3 x AC 400 V at industrial mains frequencies of 50–60 Hz. Its power section is rated for a continuous output of 250 A, allowing it to drive high-inertia spindles without current derating during sustained operation. Heat generated by the power semiconductors is removed through internal blower cooling; a built-in fan circulates air through dedicated channels so no external heat exchanger is required. Command and diagnostic data reach the control board over the SERCOS fiber ring that terminates at the front-mounted X4 optical waveguides. The optical connection helps maintain reliable data transfer in cabinets exposed to electrical noise from motors and switching devices.

An additional bleeder is integrated so regenerated energy during rapid deceleration is dissipated in a resistor network instead of returning to the DC link. The lack of an additional encoder input simplifies wiring in applications that rely solely on spindle-mounted sensors. This arrangement also reduces the number of separate feedback connections that must be routed to the drive enclosure. Velocity reference values are transmitted across the deterministic fiber-optic link, matching current CNC control architectures and keeping command exchange consistent with the communication path used by the control system. The controller is series 2 and version 2.