Product Description:

The RAC 2.2-250-380-A0S-W1 drive is an AC main spindle drive controller produced by Bosch Rexroth Indramat within the RAC Spindle Drive Controllers series. It is designed to regulate the rotational speed of machining center spindles by converting analog command signals from a CNC or PLC into controlled three-phase power for induction or synchronous motors. By managing high current demand and processing motor feedback, the unit supports stable spindle operation during cutting, drilling, and grinding tasks. This makes it suitable for machine tools that require consistent speed control as load conditions change during operation.

Its power stage is matched to a rated connection voltage of 3 x AC 400 V, 50-60 Hz, allowing integration with common factory mains. The unit can deliver a continuous output of 250 A, which supports large spindle motors with substantial current demand. Cooling is provided by a built-in fan, so air moves through the housing without requiring external ducting. The drive accepts its speed reference through an analog ±10 V input, allowing a compatible controller to modulate spindle speed with a bipolar voltage signal. For communication and diagnostics, the unit includes an RS-232-C serial interface, which allows access to operating data and parameter transfer through standard serial communication.

The unit is Series 2 and version 2. Electrical disconnection is handled through an X4 9-pole terminal block, which provides a straightforward connection point within the control cabinet. The drive is supplied without an additional bleeder, so regenerative energy must be handled by the DC link or by an external resistor connected elsewhere in the system. It is also supplied without an additional encoder input, so spindle speed feedback is expected through the primary tachometer channel. These features keep the control layout straightforward while preserving the intended spindle-control function of the drive.