Siemens 1FK7100-2AF71-1QA0 SIMOTICS S 1FK7-CT 3.8 kW 18 Nm 3000 rpm Servo Motor

The Siemens 1FK7100-2AF71-1QA0 is a SIMOTICS S 1FK7-CT synchronous servo motor rated 3.8 kW, delivering 18 Nm standstill torque (M0, 100K duty) at a 3000 rpm rated speed with an 8-pole, 8.0 A design. It is naturally cooled, IMB 5 flange-mounted, and fitted with an absolute single-turn 20-bit encoder on a DRIVE-CLiQ interface, IP64-rated, without a holding brake.

Technical Specifications

Selection Notes

The -2AF71 code sets this motor to a 3000 rpm rated speed within the 1FK7-CT line, the higher-speed winding compared with the -2AC71 version rated to 2000 rpm at the same 18 Nm standstill torque; here the higher rated speed lifts rated power to 3.8 kW even though the standstill torque is unchanged. The -1QA0 suffix means no integrated brake, keeping moment of inertia at 54.0 kgcm2 and weight at 17.6 kg, lower than the brake-equipped configuration in this frame, and keeping the 2.00 ms mechanical time constant as fast as this design allows. Choose this non-brake configuration for horizontal axes or where an external holding mechanism already covers power-off retention; for vertical or gravity-loaded axes, a holding-brake version of this motor is the safer choice. The 183,000 Nm/rad torsional stiffness and 7.3 mH rotating field inductance support stiff, high-bandwidth loops at the 3000 rpm rated speed.