Product Description:

The RAC 3.5-200-460-A00-Z1-220 is an AC main spindle drive controller released by Bosch Rexroth Indramat within the RAC Spindle Drive Controllers series. Designed to regulate high-power spindle motors on machining centers and similar equipment, the controller receives three-phase line power and converts it to controlled frequency and voltage so the spindle can maintain commanded speed and torque profiles. In machine tools, it supports stable spindle operation during drilling, milling, and similar processes where load can change quickly from one cut to the next. The unit is part of series 3, placing it within the third design generation of the RAC family.

The controller accepts 3 × AC 400 V, 50 Hz, ±15% or 3 × AC 460 V, allowing use on European and North American power grids without a transformer. Its continuous output reaches 200 A, which supports large-frame asynchronous or synchronous spindle motors during heavy cutting loads. This current capacity helps the drive support strong spindle acceleration and sustained duty under changing process conditions. Cooling is provided by a built-in fan, so no external ducting is required to move heat away from internal components. Closed-loop speed regulation uses a ±10 V analog command, making it easy to interface with CNC controls. The analog command input suits control architectures that use voltage-based spindle references instead of digital command channels.

For cabinet integration, the front panel includes terminal X4 with 9 poles for status signals and I/O wiring, while the control section is powered separately by AC 230 V at 50/60 Hz. This auxiliary supply keeps the logic section active during spindle shutdowns so control functions can remain available when the power stage is not driving the motor. During rapid deceleration, additional bleeder resistors dissipate regenerated energy without requiring an external unit. The controller is Version 5, and the model does not include additional encoder input beyond the standard spindle feedback interface. Because no extra encoder expansion is provided, the drive relies on the primary spindle encoder through the standard feedback path.