Siemens 1FK7101-2AF71-1QB0 SIMOTICS S 1FK7-CT 4.9 kW 27 Nm 3000 rpm Holding Brake Servo Motor

The Siemens 1FK7101-2AF71-1QB0 is a SIMOTICS S 1FK7-CT synchronous servo motor rated 4.9 kW, delivering 27 Nm standstill torque (M0, 100K duty) at a 3000 rpm rated speed with an 8-pole, 11.6 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 plus an integrated holding brake, for IP64-rated position retention on vertical axes.

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 27 Nm standstill torque; the lower 1.44 Nm/A torque constant on this winding means the full 11.6 A rated current is needed to hold 27 Nm. The -1QB0 suffix adds the integrated holding brake, which raises moment of inertia to 87.0 kgcm2 and motor weight to 27.5 kg compared with the non-brake configuration in this frame, so this needs to be folded into the drive's inertia-matching at the 1.62 ms mechanical time constant. Pick this brake configuration for vertical or gravity-loaded axes that must hold position when the servo drive de-energizes; on a horizontal axis without a fail-safe holding requirement, the non-brake version in the same frame carries less inertia. The 116,000 Nm/rad torsional stiffness and 60-minute thermal time constant still support sustained-torque duty at the 3000 rpm rated speed once the brake mass is accounted for.