Product Description:

The RAC 3.5-150-460-D00-Z1-220 belongs to the RAC Spindle Drive Controllers series produced by Bosch Rexroth Indramat. As an AC main spindle drive controller, it governs the rotational speed and torque of high-power machine tool spindles, allowing coordinated motion within automated machining centers. Its task is to convert digital speed references into three-phase output that matches the demands of turning, milling, or grinding equipment while maintaining electrical protection and thermal stability.

The power section is designed for a mains input of 3 x AC 400 V at 50 Hz ±15% or 3 x AC 460 V, giving the unit flexibility on facilities wired for either European or North American voltages. A continuous output capability of 150 A lets the controller deliver high spindle torque during heavy cuts. Control logic is powered separately through AC 230 V / 50–60 Hz, which keeps the control electronics isolated from disturbances on the power stage. To move heat away from internal semiconductor modules, the unit uses a built-in blower, eliminating the need for external cooling ducts inside the cabinet. Field wiring and diagnostic signals land on the X4 25-pole connector, which groups control, braking, and monitoring conductors into a single plug.

A high-resolution command path is provided by the 16-bit parallel digital speed interface, so the spindle controller can reproduce small speed changes requested by CNC logic without interpolation errors. During rapid deceleration, the integrated resistor bank includes an additional bleeder, which dissipates regenerated energy and helps prevent DC-bus overvoltage. The unit is supplied without an additional encoder input, so spindle position feedback is expected through the primary motor encoder supported by the base design. The controller is at revision level 5.