LTU Servo Amplifiers

Built for Indramat tightening systems, LTU Servo Amplifiers serve as the power and control interface for ErgoSpin tightening spindles and compatible hand-held nutrunners. Instead of operating as a standalone drive, the LTU functions as part of a complete fastening channel installed in a BT356 card rack or SB35x system box. It supplies the connected tool with motor power and logic power while also carrying the required interface signals through a dedicated spindle connector. During operation, the amplifier controls motor current and speed to support consistent tightening performance. Operators can view tightening data directly from the front LC display, including torque, angle, gradient, cycle time, and error codes. Multi-color LEDs provide quick status indication for machine-side diagnostics. The amplifier runs from a 160–320 VDC intermediate DC link and produces a three-phase 0–230 VAC motor output with frequency capability up to 1000 Hz. Depending on the connected motor, output current can reach up to 12 A rated and 50 A peak. For cabinet installation, the LTU series is specified with IP20 installed protection, a 100 m maximum motor cable length, and operation up to 55 °C when used with fan cooling.