Product Description:

Bosch Rexroth Indramat manufactures the RAC 3.5-100-460-API-W1-220 within the RAC Spindle Drive Controllers series. It is an AC main spindle drive controller with series code 3 and version 5, built to regulate high-speed machine-tool spindles in automated production lines. By modulating current and voltage to the motor, the unit maintains commanded spindle speed and torque during cutting, drilling, or grinding operations.

The power stage is rated for a continuous output of 100 A, allowing it to drive large-frame spindle motors without saturation. Mains power can be supplied at 3 × AC 400 V or 3 × AC 460 V, both centered on a 50 Hz network with a ±15% tolerance, so the same controller can be used in European or North American plants. Control electronics are energized separately at AC 230 V / 50–60 Hz, isolating the logic from line disturbances. Speed references are accepted through an analog ±10 V input, which provides a simple interface for PLC or CNC cards that convert voltage in proportion to revolutions per minute. Thermal dissipation is handled by an internal blower, eliminating the need for external ducting and helping keep cabinet temperatures within the normal operating range. The design omits an additional bleeder resistor, so regenerative energy must be absorbed by the connected DC link or external components.

Signal connectivity follows a dedicated layout. Power-on diagnostics and command lines reach the controller through the X4 9-pole terminal, simplifying field wiring. For position-synchronous machining, an additional encoder input captures spindle feedback, while an incremental encoder output passes conditioned pulses to the CNC for real-time coordination with linear axes. A high-resolution INDRAMAT encoder format is supported, giving fine angular resolution for contouring tasks and thread cutting. These feedback resources combine with the analog speed command to close velocity and position loops without complex fieldbus hardware.