VFD vs Servo Drive: Key Differences
A side-by-side comparison of VFD and servo drive motor type, feedback, dynamic response, overload rating, cost, and applications for industrial engineers.
The Siemens 1FK7042-2AF71-1QA0 is a SIMOTICS S-1FK7 (1FK7-CT) permanent-magnet synchronous servo motor rated 0.82 kW at 3,000 rpm, delivering 3 Nm standstill torque (M0, 100K) from a 600 V DC link. It has no holding brake, carries a single-turn 20-bit DRIVE-CLiQ absolute encoder (AS20DQI), and is naturally cooled in a shaft height 48, IMB 5 (IM V1/V3) housing rated IP64.
This winding is rated for a 600 V DC link at 3,000 rpm, drawing 2.0 A for the same 3 Nm standstill torque as the other 1FK7042 windings in this batch — pick it over the 300 V/3,000 rpm winding when the drive runs a standard 600 V DC bus, and over the 2,000 rpm winding when the application needs the higher speed at the same frame and torque. Its 1.38 Nm/A torque constant and 89.0% efficiency sit between the 2,000 rpm and 6,000 rpm windings in the same frame. No holding brake is fitted; the with-brake version of this winding is the choice for vertical or overhung axes.
Used as the servo motor in single- or multi-axis machine motion needing a moderate speed range on a standard 600 V DC-link drive — indexing tables, conveyor drives, and pick-and-place arms — driven through a DRIVE-CLiQ-based servo drive via the AS20DQI single-turn absolute encoder interface. The naturally-cooled IMB 5 housing suits panel- or machine-frame-mounted installations without forced-air cooling.
| Rated speed (100 K) | 3,000 rpm |
|---|---|
| Number of poles | 8 |
| Rated torque (100 K) | 2.6 Nm |
| Rated current | 2.0 A |
| Static torque (60 K) | 2.50 Nm |
| Static torque (100 K) | 3.00 Nm |
| Stall current (60 K) | 1.80 A |
| Stall current (100 K) | 2.20 A |
| Moment of inertia | 2.900 kgcm² |
| Efficiency | 89.0 % |
| Torque constant | 1.38 Nm/A |
|---|---|
| Voltage constant at 20º C | 90.0 V/1000*min¯¹ |
| Winding resistance at 20º C | 4.67 Ω |
| Rotating field inductance | 35.0 mH |
| Electrical time constant | 7.50 ms |
| Mechanical time constant | 2.15 ms |
| Thermal time constant | 30 min |
| Shaft torsional stiffness | 15,500 Nm/rad |
| Net weight of the motor | 4.6 kg Permanent-magnet synchronous |
| Motor type | motor Compact |
|---|---|
| Shaft height | 48 |
| Cooling | Natural cooling |
| Radial runout tolerance | 0.040 mm |
| Concentricity tolerance | 0.08 mm |
| Axial runout tolerance | 0.08 mm |
| Vibration severity grade | Grade A |
| Connector size | M23 |
| Degree of protection | IP64 |
| Design acc. to Code I | IM B5 (IM V1, IM V3) |
| Temperature monitoring | Pt1000 temperature sensor |
| Electrical connectors | Connectors for signals and power rotatable |
| Color of the housing | Standard (Anthracite RAL 7016) |
| Holding brake | without holding brake |
| Shaft end | Feather key |
| Encoder system | Encoder AS20DQI: absolute encoder single-turn 20 bits |
| Part number | 1FK7042-2AF71-1QA0 |
|---|---|
| Brand | Siemens |
| Condition | New, factory sealed |
| Source | Siemens and its authorised distributors |
| Warranty | Manufacturer warranty |
| Optimum speed | 3,000 rpm |
|---|---|
| Optimum power | 0.8 kW |
| Max. permissible speed (mech.) | 9,000 rpm |
|---|---|
| Max. permissible speed (inverter) | 6,400 rpm |
| Maximum torque | 10.5 Nm |
| Maximum current | 7.6 A |
| Rated inverter current | 3A |
|---|---|
| Maximum inverter current | 9A |
| Maximum torque | 10.50 Nm |
| Page 1 of 1 | Generated Sun Nov 1 02:16:03 CET 2026 |
| Shipping weight | 5.101 kg |
|---|---|
| Ships from | Türkiye |
| Dispatch | 16 Nov |
| Stock | Low stock |
Source: manufacturer data · Last verified: 01 Nov 2026
No documents are on file for this part yet.
Ask us for the datasheetThe rated current of 1FK7042-2AF71-1QA0 is 2.0 A.
The rated operational voltage of 1FK7042-2AF71-1QA0 is 600 V DC.
The rated motor power of 1FK7042-2AF71-1QA0 is 0.82 kW.
The tariff (HS) code on file for 1FK7042-2AF71-1QA0 is 85015220.
1FK7042-2AF71-1QA0 ships from Türkiye. Shipping calculated at checkout · import duties and taxes paid on arrival. Stock items are dispatched within 1–2 business days.
A side-by-side comparison of VFD and servo drive motor type, feedback, dynamic response, overload rating, cost, and applications for industrial engineers.
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