Product Description:

The RAC 2.2-250-460-A0S-W1 is an AC main spindle drive controller produced by Bosch Rexroth Indramat within the RAC Spindle Drive Controllers series. It regulates the rotational speed of machine-tool spindles by converting fixed-frequency mains power into a variable-frequency, variable-voltage output that the spindle motor can follow. This allows computer numerical control systems to command precise cutting, drilling, or grinding speeds while maintaining constant torque across a broad operating range.

The controller connects to factory power through a rated line of 3 x AC 400 V, 50 Hz, +/-15% or 3 x AC 460 V and draws a continuous phase current of 250 A, so upstream circuit protection and cabling must be sized for high-power duty. Speed references arrive as a differential signal interpreted by its ±10 V analog input; this command format is shown by the spec analog (+/- 10 V), enabling direct coupling to typical CNC control cards. Heat generated by the power electronics is removed by an actively driven air path, and the unit uses an internal blower with a built-in fan so no external cabinet air movers are required. Field wiring and monitoring leads land on terminal X4 with 9 poles, giving a single plug-in point for status outputs, enables, and fault resets.

For machine integration, a dedicated service port using an RS-232-C serial interface supports parameter backup and diagnostics without proprietary adapters. Braking energy is returned to the DC link only through the standard transistor because the device ships without an additional bleeder, so faster deceleration requires an external resistor. Position feedback expansion is also omitted because the controller comes without an additional encoder input, leaving the primary spindle encoder on the motor side. The controller is Version 2.