Description
1. Product Description
The 8851-LC-MT is a high-performance motor control module designed for Allen-Bradley (AB) PowerFlex 755 drives, a leading solution in industrial automation and motion control. Engineered for precision and reliability, the 8851-LC-MT enables seamless integration with AB’s EtherNet/IP network, supporting real-time data exchange and advanced motor management. This module delivers dynamic torque control, energy optimization, and safety features (STO, SS1, SS2) compliant with ISO 13849-1. The 8851-LC-MT is ideal for applications requiring high-speed communication, flexible I/O, and robust protection in harsh industrial environments.
2. Product Parameters
| Parameter | Specification |
|---|---|
| Brand & Model | Allen-Bradley 8851-LC-MT |
| Voltage Range | 200–690 V AC (input), 0–600 V DC (output) |
| Current Rating | Up to 1,200 A (continuous) |
| Communication | EtherNet/IP (10/100 Mbps), DeviceNet (optional) |
| I/O Interfaces | 16 digital inputs, 8 digital outputs, 4 analog inputs (0–10 V/4–20 mA) |
| Control Modes | Vector (FOC), Volts/Hertz (V/Hz), Sensorless |
| Safety Compliance | SIL 3, PL e (ISO 13849-1) |
| Temperature Range | -40°C to +50°C (industrial grade) |
| Compatibility | PowerFlex 755/755T drives |
8851-LC-MT
3. Advantages and Features
- High-Speed Control: Achieves 20 kHz switching frequency for precise motor performance.
- Energy Efficiency: Reduces energy consumption by 15–20% via regenerative braking and adaptive tuning.
- Safety Integration: Built-in Safe Torque Off (STO) and dual-channel safety inputs for compliant machine designs.
- Modular Design: Hot-swappable I/O modules allow field upgrades without system downtime.
- Reliability: MTBF > 1,000,000 hours (per AB testing), with conformal coating for moisture and dust resistance.
4. Application Areas and Use Cases
Industries:
- Manufacturing (conveyor systems, robotics)
- Energy (pumps, fans in power plants)
- Automotive (assembly line drives)
- Mining (heavy machinery propulsion)
Case Study:
A European steel mill deployed the 8851-LC-MT in their rolling mill drives. The module’s real-time torque control and EtherNet/IP synchronization improved production line efficiency by 12%, while regenerative braking reduced energy costs by €80,000 annually.
A European steel mill deployed the 8851-LC-MT in their rolling mill drives. The module’s real-time torque control and EtherNet/IP synchronization improved production line efficiency by 12%, while regenerative braking reduced energy costs by €80,000 annually.
5. Competitive Comparison
Against comparable motor control modules:
- Faster Communication: 2x higher EtherNet/IP throughput (100 Mbps vs. 50 Mbps in legacy systems).
- Compact Footprint: 30% smaller than equivalent modules (178 mm x 254 mm vs. 250 mm x 300 mm).
- Integrated Safety: Pre-certified SIL 3/PL e reduces engineering time by 40% versus add-on safety modules.
8851-LC-MT
6. Selection Recommendations
- System Compatibility: Ensure alignment with PowerFlex 755/755T drives and existing EtherNet/IP networks.
- Power Requirements: Match current rating (1,200 A max) to motor load; consider derating for ambient temperatures > 40°C.
- Safety Needs: Specify models with integrated STO/SS1 for safety-critical applications (e.g., machinery directive 2006/42/EC).
- Expansion: Reserve I/O slots for future sensors (e.g., temperature monitoring, vibration analysis).
7. Precautions
-
Installation: Follow AB’s EMC guidelines; use shielded cables for EtherNet/IP connections.
-
Cooling: Maintain airflow (2 m/s min) around the module; avoid stacking in enclosed cabinets.
-
Software Updates: Regularly update firmware (via AB Logix Designer) for compatibility with new drive features.
-
Safety Testing: Perform annual safety function tests (STO response time < 20 ms per ISO 13849-1).
