Product Description:

The Bosch Rexroth Indramat RAC 3.1-100-460-A0I-W1-220 belongs to the RAC Spindle Drive Controllers series, which is intended to regulate high-speed machine-tool spindles in automated machining centers. As an AC main spindle drive controller, it sits between the plant's three-phase supply and the spindle motor, generating the variable frequency and current needed for precise speed regulation, rapid acceleration, and controlled deceleration during drilling, milling, or grinding. The unit also provides monitoring channels so the numerical control can supervise torque limits and diagnostic status while motion is underway. This type of controller is used where stable spindle speed and quick response are required as cutting loads change during a machining cycle. It is supplied as version 1.

Power for the drive section is supplied from 3 x AC 400 V or 3 x AC 460 V, permitting installation in both European and North American electrical systems. The control electronics are energized separately at AC 230 V at 50/60 Hz, which isolates sensitive circuitry from spindle surges. Separating the control supply from the main drive input helps the low-level electronics remain stable during rapid spindle load changes. Under continuous duty, the controller can deliver up to 100 A, a current level suited to large induction or synchronous spindle motors. Heat generated by the switching devices is removed by an internal blower, so no external ducting is required. Velocity commands reach the controller as a differential analog (±10 V) signal, allowing CNC cards to impose spindle speed setpoints.

The signal layout is streamlined to match the drive's high-speed role. Motor feedback can be duplicated from an incremental encoder output, while the base design comes without an additional encoder input so the control loop remains focused on the primary feedback channel. The unit is also supplied without an additional bleeder. This arrangement keeps extra signal routing to a minimum and keeps the cabinet interface straightforward for the connected control hardware. All field connections converge on terminal X4, 9 poles, providing a single plug point for the analog command, interlocks, and diagnostic lines.