What the 1FK2104-5AK11-1MB0 is, in one paragraph
The 1FK2104-5AK11-1MB0 is a Siemens SIMOTICS S-1FK2 HD servo motor from the 1FK2 family, intended for pairing with the SINAMICS S120 drive line via the DRIVE-CLiQ M17 plug and the M17 power connector. It is a M0=2.4 Nm high-dynamics servomotor with an integrated holding brake — the kind of unit that holds a vertical axis in place when the drive is de-energised, so a stopped machine does not drop its load before the mechanical brake engages. Lifecycle stage is recorded as current on the order code, and the product is classed as made-to-order — that class C designation means each unit is built against the BOM rather than pulled from a finished-goods shelf, which is why sourcing flows through quotation rather than pick-and-ship.
Headline ratings and what they actually decide
The continuous torque floor M0=2.4 Nm sets the sizing basis; PN=1.07 kW at nN=6000 rpm on the 380–480 V rail, and PN=0.75 kW at nN=3000 rpm on the 200–240 V rail, so the same shaft frame works on both common industrial mains voltages without a rewind. The dual rating is a deployment convenience — the drive parameter set is what selects the operating point, not the motor. IP65 on the housing means the motor body withstands low-pressure water jets and dust ingress — washdown-capable in food-and-bev or machine-tool cells, though it is not a fully submerged rating and should not be specified for IP67/IP68 duties. The shaft is D19×40 mm with feather key, matched to the standard 1FK2 coupling footprint; the encoder is the 22-bit single-turn plus 12-bit multi-turn absolute unit (AM22DQC), so position survives a power cycle without re-homing.
Integration into a SINAMICS S120 panel
The DRIVE-CLiQ M17 plug carries the encoder feedback and electronic nameplate to the S120 control module — auto-configuration in STARTER or Startdrive pulls the motor parameters from the encoder memory, so a swap on a commissioned axis restores the tuning set without a manual parameter re-entry. The M17 power connector on the motor side carries the phase leads; on the panel side, sizing it to the S120 Motor Module's rated output and the cable length's voltage-drop budget is the integrator's call, not the motor's. Because the unit carries a holding brake, the brake release contact is wired through the drive's brake control output — a mis-wired brake (energised when the drive expects it released, or vice versa) is the single most common field fault on this family. Verify the brake logic against the SINAMICS commissioning diagram before the first enable, not after the first drop.
Compliance and documentation posture
The motor has been RoHS-compliant since 01-07-06 and carries the REACH Article 33 duty-to-inform disclosure for current candidate-list substances. No additional regional certifications (UL, CSA, CE) are recorded on the order-code listing — those follow from the SINAMICS S120 system's approvals rather than the motor's own certificate set, and the integrator's declaration of conformity covers the assembled machine.
Ordering and BOM-fit
Orderable as one piece per packaging unit, Group Code R220 within Product Group 9021. Because the unit is class C made-to-order and the SINAMICS drive system tuning is calibrated to the encoder's electronic nameplate, an unqualified substitution is not a BOM swap — it is a re-commissioning job. For multi-axis builds, lock the order code across all axes before release — a mid-build variant change resets every axis's auto-commissioning parameters.