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Kollmorgen S74801-NA-024
Model Number: S74801-NA-024
Product Introduction:
The S74801-NA-024 is a high-performance AC servo motor designed specifically for use with Kollmorgen’s S700 series servo drives. The model number decodes as: S7 (S700 series), 48 (frame size S748), 01 (stack length 01), NA (standard winding), 024 (24 V brake or specific variant). This motor delivers high torque at high speed with an integrated multi-turn absolute encoder.
Detailed content
Technical Specifications:
| Parameter | Value |
|---|---|
| Frame Size | S748 (NEMA 34 equivalent, larger than S614) |
| Stator Outer Diameter | 140 mm (approx.) |
| Stack Length | 01 (long stack for S748 frame) |
| Rated Torque (Continuous) | 23.9 Nm |
| Peak Torque | 71.7 Nm (3× rated, 10 s) |
| Rated Speed | 3000 RPM (continuous) |
| Max Speed | 4500 RPM |
| Rated Power (Continuous) | ~7.5 kW |
| Winding Code | NA (Rated voltage: 480 V AC line-to-line) |
| Feedback Device | Multi-turn absolute encoder (EnDat 2.2 / BiSS-C, 2048 lines, up to 4096 turns) |
| Holding Brake | With electromagnetic brake (24 V DC, 40 Nm holding torque) |
| Insulation Class | Class F (155°C) |
| IP Rating | IP65 (with optional seal kit) / IP54 (standard) |
| Weight | ~14.5 kg |
| Shaft Type | Keyed shaft with D-cut, 28 mm diameter |
| Bearings | Deep groove ball bearings (sealed, greased for life) |
| Cooling | IC416 (forced air) — fan-cooled |
Structural Characteristics:
- Cast aluminum housing with precision-machined mounting flange
- NdFeB (Neodymium) magnets — Class 150°C for high-temperature operation
- 48 slots / 6 poles stator configuration with skewed slots for minimal cogging
- Double-sealed bearings — rated for L10 life > 20,000 hours at rated speed
- Integrated KTY84 temperature sensors in all three winding phases
- Stainless steel shaft (standard) or carbon steel (optional)
Performance Parameters:
| Parameter | Value |
|---|---|
| Torque Constant (Kt) | 0.76 Nm/A (typical) |
| Back-EMF Constant (Ke) | 7.2 V/krpm (typical) |
| Rotor Inertia | ~85 × 10⁻⁴ kg·m² (8500 × 10⁻⁶ kg·m²) |
| Mechanical Time Constant | ~45 ms |
| Electrical Time Constant | ~4 ms |
| Torque-to-Inertia Ratio | ~281 Nm/kg·m² |
| Moment of Inertia (Jm) | 85 × 10⁻⁴ kg·m² |
Advantages:
- 7.5 kW continuous power — one of the highest in the S700 lineup
- Multi-turn absolute encoder (4096 turns) — zero homing required
- 40 Nm holding brake — robust load retention
- IP65 rated — washdown-capable
- Optimized for S700 drive — auto-identification and one-button tuning
Applicable Industries:
Large CNC machines, metal forming presses, injection molding (large clamp), robotics (heavy payload arms), wind energy pitch control, marine thrusters
Installation Requirements:
- Mount using 4× M10 mounting holes on front flange (NEMA 34 pattern)
- Shaft coupling: Bellows or disc coupling recommended — max misalignment: 0.15 mm radial, 0.15° angular
- Brake wiring: 24 V DC, max 0.5 A continuous, 2 A peak (release)
- Encoder cable: Shielded twisted pair, minimum bend radius 100 mm
- Forced air cooling required — ensure minimum 2 m/s airflow across motor body
Usage Notes:
- Do not exceed 4500 RPM — configure overspeed limit in S700 drive
- Brake release time: ~40 ms — include in motion profile planning
- Derate torque 1% per °C above 40°C ambient
- Perform encoder zero-offset calibration during commissioning via Kollmorgen Workbench
