1FK7042-5AF71-1EG3-2 is a compact permanent magnet synchronous servo motor from Siemens SIMOTICS S series, designed for high-performance automation and motion control systems, and fully compatible with the SINAMICS S120 drive system.
| Segmento modello | Descrizione |
| 1FK7 | Serie di motori: 1FK7 compact permanent magnet synchronous servo motor, natural cooling |
| 42 | Motor size: shaft height 42 mm, corresponding to 3 Nm rated torque class |
| 5AF71 | Design and specification: 5AF = standard design; 71 = mounting dimensions and cooling method (natural cooling) |
| 1EG3 | Encoder and options: E = encoder type; G3 = specific encoder configuration (with DRIVE-CLiQ interface) |
| 2 | Additional feature: usually indicates electromagnetic brake to prevent shaft movement during power loss |
- Parametri tecnici fondamentali
| Articolo | Specifica |
| Coppia nominale | 3.0 Nm (100K temperature class) |
| Potenza nominale | 0.82 kW (1.1 HP) |
| Rated speed | 3000 giri/min |
| Corrente nominale | 1.95 UN |
| Metodo di raffreddamento | Raffreddamento naturale (no external fan required) |
| Tipo di montaggio | IM B5 (IM V1, IM V3) – flange mounting |
| Classe di protezione | Standard IP65 (IP64 at shaft end); higher protection optional |
| Tipo di codificatore | Encoder assoluto (identified by 1EG3), with DRIVE-CLiQ interface |
| Connector feature | Power/signal connectors rotatable through 270° for easy wiring |
| Rotor inertia | Low-inertia design for improved dynamic response |
| Peso | ca. 4.9–5.0 kg (without brake) |
| Number of pole pairs | 4 |
- Key Features and Advantages
- High-performance permanent magnet design: Uses rare-earth permanent magnets for high power density, high efficiency and low energy consumption.
- High overload capability: Withstands short-term overload above 3x rated torque to adapt to dynamic load changes.
- Precise control: Achieves high-precision positioning and speed control with SINAMICS S120 drives.
- Brake function: Suffix “2” means electromagnetic brake, suitable for vertical axes or gravity-loaded applications to prevent dropping when powered off.
- Installazione flessibile: IM B5 flange mounting, rotatable connectors, adaptable to various mechanical layouts.
- Reliability and durability: IP65 protection, adatto per ambienti industriali difficili, long bearing life.
- Diagnostic function: Provides comprehensive motor status monitoring and diagnostics via DRIVE-CLiQ.
- Applicazioni tipiche
- Linee di produzione automatizzate: Precise control of conveyors, positioning stages, assembly machinery.
- Robotics: Joint drives, end-effector positioning, especially applications requiring position retention at power loss.
- Macchine per l'imballaggio: High-speed, precise control of paper feeding, bag making, sigillatura, ecc.
- Attrezzature per la stampa: Register accuracy control, web tension regulation.
- Macchine utensili: Feed and spindle drives for CNC milling machines, torni.
- Apparecchiature per semiconduttori: Wafer handling, positioning platforms requiring high cleanliness and precision.
- Attrezzature mediche: Precise motion control for diagnostic and therapeutic devices.
- Model Comparison within the Same Series
| Modello | Differenza principale | Applicazione |
| 1FK7042-5AF71-1EG0 | Without brake | Horizontal axis, non-gravity load |
| 1FK7042-5AF71-1EG3 | Con freno (questo modello) | Vertical axis, gravity load, position retention required at power loss |
| 1FK7042-5AF71-1EG5 | Different encoder resolution | Applications requiring higher positioning accuracy |
| 1FK7042-5AF71-1GG5 | Basic absolute encoder (32 P/REV) | Cost-sensitive applications with moderate accuracy requirements |
| 1FK7042-5AF71-1FA0 | Encoder assoluto (2048 P/REV) | High-precision positioning applications |
- Drive Compatibility and Replacement Solutions
- Recommended drive: SINAMICS S120 series, perfectly matched to 1FK7 series characteristics.
- Modelli alternativi:
Siemens replacement: 1FT7042 series (mechanically compatible, prestazioni simili)
Third-party alternatives: Schneider LXM series, ABB ACS series, Mitsubishi MR-J series (observe parameter matching)
- Upgrade path: For higher performance, consider 1FK7060 (5 Nm) or 1FK7080 (8 Nm).
- Linee guida per l'installazione e la manutenzione
- Pre-installation checks:
Confirm compatibility between motor and drive system.
Inspect motor appearance and shaft condition.
Verify encoder type and interface.
- Installation precautions:
Ensure flatness during flange mounting to avoid eccentric load.
Rotate connectors to optimal wiring position (massimo. 270°).
Correctly connect brake wiring to the brake control terminal of the drive.
- Maintenance recommendations:
Regularly check motor temperature (normal operating temperature < 85 °C).
Keep motor clean to avoid dust buildup affecting heat dissipation.
Periodically verify brake operation for reliable holding when de-energized.
Protect encoder cables from strong electromagnetic interference.
1FK7042-5AF71-1EG3-2 is a 3 Nm compact permanent magnet synchronous servo motor from Siemens SIMOTICS S series, equipped with absolute encoder and brake, naturally cooled. It is ideal for industrial automation applications requiring high-precision positioning and position retention at power loss.
With low inertia and high overload capability, it performs excellently in high dynamic response applications, and achieves outstanding motion control performance with the SINAMICS S120 drive system.
Siemens 1FK7042 Series Servo Motor: Complete Coding System and Cross-Brand Alternatives
- Full Model Naming Convention
Each segment of 1FK7042-XXXXX-XXXX-X has a clear meaning that defines core properties and configuration:
| Segmento | Codice | Descrizione |
| 1FK7 | Prefisso fisso | Siemens SIMOTICS S compact PMSM, natural cooling |
| 42 | Size code | Shaft height 42 mm, 3 Nm rated torque; 04 = shaft height, 2 = length class |
| XX | Design type | 2A = standard compact |
| 3B = high inertia | ||
| 5A = compact (510V–720V) | ||
| 2C = high dynamic | ||
| F71 | Raffreddamento & montaggio | F = standard flange; 7 = with connector; 1 = natural cooling |
| 1XX | Tipo di codificatore | 1E = absolute (DRIVE-CLiQ) |
| 1F = incremental | ||
| 1P = resolver | ||
| 1Q = absolute 20-bit single-turn | ||
| 1R = absolute 24-bit single-turn + 12-bit multi-turn | ||
| X | Additional feature | 0 = no brake |
| 2 = with electromagnetic brake | ||
| 3 = special protection | ||
| 5 = with incremental encoder | ||
| X | Interface/accuracy | G3 = DRIVE-CLiQ, alta risoluzione |
| A0 = standard accuracy | ||
| H2 = with mechanical brake | ||
| U0 = incremental encoder (±1 pulse accuracy) |
- Complete 1FK7042 Model List (by Configuration)
2.1 Standard Compact (2A/5A) Basic Configurations
| Modello completo | Configurazione principale | Applicazione |
| 1FK7042-2AF71-1AG0 | 3Nm, 3000giri/min, 0.82kW, incremental encoder, no brake | Horizontal drive, general positioning accuracy |
| 1FK7042-2AF71-1QG0 | 3Nm, 3000giri/min, 0.82kW, 20-bit single-turn absolute encoder, no brake | Posizionamento ad alta precisione, position memory at power loss |
| 1FK7042-2AF71-1RB0 | 3Nm, 3000giri/min, 0.82kW, 24-bit single-turn +12-bit multi-turn absolute encoder, no brake | Multi-axis linkage, complex motion control |
| 1FK7042-5AF71-1EG3-2 | 3Nm, 3000giri/min, 0.82kW, absolute encoder (DRIVE-CLiQ), with brake | Vertical axis, gravity load, anti-drop at power loss |
| 1FK7042-5AF71-1FH3 | 3Nm, 3000giri/min, 0.82kW, incremental encoder, with brake | High-speed reciprocating motion, high dynamic response |
| 1FK7042-2AF71-1PA0 | 3Nm, 3000giri/min, 0.82kW, resolver, no brake | Harsh EMI environment, high anti-interference requirement |
| 1FK7042-2AF71-1CB0 | 3Nm, 3000giri/min, 0.82kW, absolute encoder, special protection | Dust/moist environment, IP67 |
2.2 High-Inertia / High-Dynamic Special Configurations
| Modello completo | Configurazione principale | Applicazione |
| 1FK7042-3BK71-1QH2 | 3Nm, 3000giri/min, 0.9kW, high inertia, absolute encoder, with brake | Large inertia matching, smooth start/stop |
| 1FK7042-2AC71-1QA0 | 3Nm, 6000giri/min, 1.8kW, high dynamic, absolute encoder, no brake | High-speed positioning, risposta rapida |
| 1FK7042-2AK74-1TH0 | 3Nm, 6000giri/min, 0.9kW, compatto, resolver, with brake | High-speed motion, anti-interference required |
- Mainstream Brand Alternatives (3 Nm Class)
3.1 Siemens Internal Replacements
| Originale | Alternativa | Compatibilità |
| 1FK7042-5AF71-1EG3-2 | 1FT7042-5AF71-1CH1-Z N05 | Fully mechanical compatible, same performance, same encoder interface |
| 1FK7042-2AF71-1QG0 | 1FK7042-5AF71-1QH0 | Optimized voltage range, otherwise identical |
| 1FK7042-2AF71-1PA0 | 1FK7042-5AF71-1PH0 | Upgraded resolver interface, protezione migliorata |
3.2 Schneider Electric
| Alternativa | Ordine n. | Parametri di corrispondenza chiave |
| BCH2MF0733CA1C | 140S-M-0733 | 3Nm, 3000giri/min, 0.85kW, absolute encoder, with brake |
| LXM32AD18M2+BSH0701P01A2A | 9020-0701 | Drive+motor set, 3Nm, 3000giri/min, compatible with SINAMICS environment |
3.3 ABB
| Alternativa | Ordine n. | Parametri di corrispondenza chiave |
| MotiFlex e180+M3AA08060HB | 3ABD00012600 | 3Nm, 3000giri/min, 0.82kW, absolute encoder, with brake |
| ACS880-01-040A-5+MQM0804-0300 | 3AXD50000038924 | Drive+motor set, fits 1FK7 mounting dimensions |
3.4 Mitsubishi
| Alternativa | Ordine n. | Parametri di corrispondenza chiave |
| MR-J4-350B+HF-KP43 | MR-J4-350B+HF-KP43B | 3.5Nm (compatible with 3Nm), 3000giri/min, absolute encoder, with brake |
| MR-J5-350B+HF-KP43B | MR-J5-350B+HF-KP43B | Nuova generazione, optimized communication, ~15% performance boost |
3.5 OMRON
| Alternativa | Ordine n. | Parametri di corrispondenza chiave |
| R88M-G30030H-S2-Z | R88M-G30030H-S2-Z | 3Nm, 3000giri/min, 0.8kW, absolute encoder, with brake |
| 1S Series + R88D-1SN03H-ECT | 1S030-30CB2-D + R88D-1SN03H-ECT | Integrated safety, SIL3 certified, for harsh industrial environments |
- Key Guidelines for Replacement Selection
- Parameter matching priority:
Coppia nominale (3 Nm) > Rated speed (3000 giri/min) > Energia (0.82 kW) > Rotor inertia > Classe di protezione
Encoder type must match the system (absolute / incrementale / resolver)
Freno (suffisso 2) is mandatory for vertical axes.
- Mechanical compatibility:
Match flange (IM B5), shaft diameter, keyway to original equipment.
Connectors rotatable 270° for wiring convenience.
Brake wiring must match drive brake control terminals.
- Drive compatibility:
Siemens SINAMICS S120 works natively with 1FK7/1FT7.
Third-party drives must support the encoder interface (DRIVE-CLiQ / SSI / incrementale).
Same-brand drive-motor combinations are recommended to minimize issues.
The 1FK7042 series is the core 3 Nm torque class product in the Siemens SIMOTICS S family.
With various encoder, brake and protection configurations, it covers standard industrial to harsh environment applications.
When selecting replacements, prioritize matching torque, velocità, encoder type and mounting dimensions, while ensuring drive compatibility and long-term supply stability.
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