Company Information
E-mail		[email protected]
Mobile		+8615980777398
Whatsapp		+8615980777398
WeChat		15980777398

Allen-Bradley MPL-B680D-MJ72AA Servo Motor — Detailed Product Specifications, Introduction, Applications, Advantages, and Model Recommendations

1. Product Overview

The MPL-B680D-MJ72AA is a large-frame, low-inertia brushless AC servo motor in the Allen-Bradley MP-Series MPL family. It is designed for industrial motion-control systems that require substantial torque, accurate position feedback, reliable speed control, and repeatable dynamic performance.

This model uses a 215 mm frame and a 203.2 mm magnetic stack, placing it toward the high-torque end of the MPL family. It is rated in the 460 V AC class, with a 2000 rpm rated speed, approximately 9.3 kW rated output, and approximately 62.8 N·m continuous stall torque.

A particularly important feature is its multi-turn high-resolution absolute encoder. Unlike a simple incremental feedback arrangement, the multi-turn configuration provides position information across multiple motor revolutions, making it useful for long-travel machine axes and mechanically demanding positioning applications.

The model has a keyed shaft, a right-angle SpeedTEC DIN connector that can be rotated approximately 180°, an IEC metric mounting arrangement, and no integral holding brake. This makes it a good fit for applications where the machine already has an independent mechanical holding arrangement or where a brake is not required.

---

2. Basic Product Information

---

3. Brand

The brand of the MPL-B680D-MJ72AA is Allen-Bradley.

Allen-Bradley servo motors are widely used in industrial automation, machine motion, material handling, packaging, machine tools, converting equipment, and other applications where closed-loop control is required.

The MPL family is designed as an industrial servo-motor platform rather than a general-purpose induction-motor range. Its design focuses on precise torque production, dynamic response, feedback accuracy, and integration with compatible servo-drive systems.

---

4. Product Series

The MPL-B680D-MJ72AA belongs to the MP-Series MPL Low-Inertia Brushless Servo Motor series.

The MPL series includes different frame sizes, motor stack lengths, winding configurations, speed ratings, encoder arrangements, shaft styles, connector configurations, and brake options.

The B680D version is one of the larger motors in this family.

The B680 designation is associated with the large 215 mm frame and 203.2 mm magnetic stack configuration, while the D winding designation corresponds to the 2000 rpm version.

The M indicates the multi-turn high-resolution absolute feedback configuration, while J identifies the keyed shaft arrangement. The 7 identifies the right-angle SpeedTEC DIN connector arrangement, and the 2 indicates the no-brake configuration.

---

5. Model Number Interpretation

The model number is useful because it gives a quick overview of the motor’s basic mechanical and electrical configuration without needing to look at the complete specification.

---

6. Detailed Technical Parameters

---

7. Dimensions

The B680 motor uses a 215 mm frame and an 80-series magnetic stack measuring 203.2 mm.

This makes it considerably larger than the shorter B640 and B660 stack configurations.

For machine design, the 215 mm frame and 203.2 mm stack are the most important basic dimensions.

The exact overall envelope should be taken from the dimensional drawing for the motor configuration being installed, especially when the available machine space is limited.

---

8. Weight

The MPL-B680D-MJ72AA weighs approximately 45.36 kg, equivalent to approximately 100 lb.

This is a relatively heavy servo motor.

For machine assembly, transportation, and maintenance, suitable lifting equipment should be considered. The motor should not be treated like a small-frame servo motor that can easily be installed by one person.

---

9. Rated Power

The MPL-B680D-MJ72AA provides approximately 9.3 kW of rated output.

This places it well above the output level of many smaller servo motors in the MPL family.

The power rating is useful for applications involving heavy loads, high acceleration requirements, large rotating mechanisms, or continuously operating mechanical systems.

The actual available mechanical output in an application depends on motor temperature, drive sizing, load inertia, acceleration profile, ambient conditions, and duty cycle.

---

10. Torque Characteristics

Torque capability is one of the main reasons to select the B680D configuration.

The motor provides approximately 62.8 N·m of continuous stall torque and approximately 154.2 N·m of peak stall torque.

This gives the motor a substantial torque reserve for acceleration and short-duration high-load conditions.

The difference between continuous and peak torque is important.

Continuous torque describes what the motor can sustain under appropriate operating conditions, while peak torque is intended for shorter-duration acceleration or high-demand portions of the motion cycle.

---

11. High Torque and Low Inertia

The MPL series is designed around a low-inertia servo concept.

For the B680D, this is particularly useful because the motor combines a large torque capability with a servo-oriented rotor design.

A high-power motor does not necessarily have to respond slowly. The low-inertia design helps the motor respond to changes in command more quickly than a conventional industrial motor of similar output might.

This can be useful in applications involving:

• Frequent acceleration and deceleration.
• Repeated positioning.
• Coordinated multi-axis motion.
• Rapid indexing.
• Load synchronization.
• Tension control.
• Precise speed regulation.

---

12. Multi-Turn Absolute Encoder

One of the strongest features of the MPL-B680D-MJ72AA is its multi-turn high-resolution absolute encoder.

The encoder provides feedback regarding the motor shaft position to the servo-drive system.

The multi-turn capability is particularly useful when the motor rotates through many revolutions during normal machine operation.

This makes the motor especially suitable for long-travel mechanical axes and rotary mechanisms requiring repeatable positioning.

---

13. Benefits of Multi-Turn Feedback

Multi-turn feedback is useful in applications such as:

• Long-travel linear actuators.
• Ball-screw axes.
• Rack-and-pinion systems.
• Large machine-tool axes.
• Automated storage systems.
• Material-transfer systems.
• Large indexing equipment.
• Vertical positioning systems.
• Industrial gantries.
• Heavy automation platforms.

The feedback system is particularly useful when the mechanical transmission causes the motor to rotate many times before the machine reaches its final position.

---

14. Keyed Shaft

The MPL-B680D-MJ72AA uses a keyed shaft extension.

A keyed shaft provides a positive mechanical connection between the motor and the driven machine component.

Typical applications include:

• Flexible couplings.
• Gearboxes.
• Timing pulleys.
• Rollers.
• Screw drives.
• Rotary tables.
• Indexing mechanisms.

The mechanical coupling must be selected according to the actual shaft dimensions, torque, speed, radial loading, axial loading, and allowable misalignment.

---

15. No Integral Brake

An important characteristic of this exact model is:

No integral brake.

This differentiates the MPL-B680D-MJ72AA from models such as the MPL-B680D-MJ74AA, which uses a brake configuration.

A no-brake version can be advantageous when:

• The machine does not need a holding brake.
• A separate mechanical brake already exists.
• The axis is horizontal.
• The load does not fall under gravity.
• Reduced motor complexity is desired.
• The application uses external safety or mechanical holding equipment.

For a vertical load, however, the absence of an integral brake must be carefully considered during machine design.

---

16. Speed Characteristics

The MPL-B680D-MJ72AA is a 2000 rpm servo motor.

Compared with the 3000 rpm B680F family, the D configuration is more focused on torque and power rather than maximum motor speed.

This makes it a good candidate for machinery where substantial torque is more important than extreme rotational speed.

---

17. Connector Design

The model uses a SpeedTEC DIN connector with a right-angle configuration.

The connector can be rotated approximately 180 degrees, which gives the machine builder more flexibility when routing cables.

This is particularly useful in compact machine enclosures where a straight connector might interfere with the machine frame.

Cable routing should still be designed to prevent excessive bending, vibration, pulling force, and mechanical stress at the connector.

---

18. Mounting Arrangement

The motor uses an IEC metric flange mounting arrangement with free mounting holes, Type FF.

This provides a standardized mechanical approach for mounting the motor to the machine.

The mounting face must be properly aligned.

Incorrect alignment can result in:

• Increased bearing loading.
• Coupling wear.
• Shaft vibration.
• Increased motor temperature.
• Reduced bearing life.
• Mechanical noise.
• Servo following errors.

---

19. Enclosure and Environmental Considerations

The exact enclosure rating can vary depending on shaft sealing and configuration.

The standard configuration is generally associated with an industrial enclosed motor housing, while shaft sealing can affect the final protection level.

The motor is intended for controlled industrial environments rather than uncontrolled outdoor exposure without appropriate protection.

Important environmental factors include:

• Ambient temperature.
• Humidity.
• Dust.
• Washdown requirements.
• Chemical exposure.
• Vibration.
• Shock.
• Condensation.
• Shaft sealing requirements.

---

20. Product Introduction

The MPL-B680D-MJ72AA is essentially a high-output industrial servo motor designed for large motion-control axes.

Its 215 mm frame and 203.2 mm stack provide a substantial electromagnetic package, while the low-inertia rotor design gives the motor the dynamic behavior expected from a servo motor.

The approximately 9.3 kW output makes it suitable for machinery where smaller servo motors may not have enough continuous power.

The approximately 62.8 N·m continuous torque and approximately 154.2 N·m peak torque also provide significant acceleration capability.

The motor’s multi-turn absolute feedback is particularly valuable for large machines because the controller can maintain accurate position information over multiple motor revolutions.

---

21. Main Advantages

21.1 High Continuous Torque

The approximately 62.8 N·m continuous stall torque gives the motor strong load-driving capability.

This is particularly valuable for large mechanical axes and systems with high reflected inertia.

---

21.2 High Peak Torque

The approximately 154.2 N·m peak stall torque provides a substantial short-term torque reserve.

This is useful during:

• Acceleration.
• Rapid positioning.
• Load changes.
• Mechanical indexing.
• Dynamic machine cycles.

---

21.3 9.3 kW-Class Output

The approximately 9.3 kW output makes the B680D appropriate for substantially larger machinery than small-frame servo motors.

---

21.4 Multi-Turn Absolute Feedback

The multi-turn absolute encoder provides high-resolution position information across multiple rotations.

This is one of the most valuable features for long-travel industrial axes.

---

21.5 Low-Inertia Construction

The low-inertia design helps maintain good servo response despite the motor’s large power rating.

---

21.6 Keyed Shaft

The keyed shaft makes the motor suitable for a wide range of industrial mechanical transmissions.

---

21.7 Flexible Connector Arrangement

The right-angle connector and approximately 180° rotational capability provide additional installation flexibility.

---

21.8 No-Brake Configuration

For applications that do not require a holding brake, the no-brake version can simplify mechanical and electrical integration.

---

22. Typical Applications

CNC and Machine Tools

The motor is suitable for large machine-tool axes where substantial torque and accurate positioning are needed.

Possible applications include:

• Heavy-duty linear axes.
• Large rotary axes.
• Machine-tool positioning.
• Tool-changing mechanisms.
• Heavy machining centers.
• Large auxiliary drive axes.

---

Material Handling

The motor can be used in large material-handling systems.

Examples include:

• Heavy conveyors.
• Transfer tables.
• Pallet systems.
• Automated positioning equipment.
• Large rollers.
• Industrial transfer units.

---

Packaging and Converting

Large packaging and converting machinery can require more torque than small servo motors can provide.

Potential applications include:

• Large rollers.
• Web handling.
• Indexing mechanisms.
• Cutting systems.
• Forming mechanisms.
• High-load feeding axes.

---

Automated Assembly

The motor can be used in large automated assembly machines where multiple axes must move accurately and repeatedly.

---

Printing and Web Processing

The combination of accurate feedback and substantial torque can make this type of motor suitable for:

• Web handling.
• Roll positioning.
• Tension-control systems.
• Feed mechanisms.
• Converting machinery.

---

Large Positioning Systems

The motor is particularly appropriate for large positioning platforms, tables, and transfer mechanisms.

---

23. Application Suitability

---

24. Five Related MPL-Series Models

The following models are useful alternatives or comparison models within the same MPL family.

The closest direct alternative is the MPL-B680D-MJ74AA, because it retains the same general frame, stack, speed, torque, and feedback family while adding a holding-brake configuration.

---

25. Five Same-Brand Commonly Compared Models

These are useful comparison models because they cover different combinations of torque, speed, stack length, brake, and feedback configuration.

---

26. MPL-B680D-MJ72AA vs MPL-B680D-MJ74AA

These two models are mechanically very close.

If the machine requires a holding brake, the MJ74AA-type configuration is more appropriate.

If the application does not need a brake, the MJ72AA version provides a simpler configuration.

---

27. MPL-B680D-MJ72AA vs MPL-B660F-MJ72AA

This is a useful comparison when deciding whether the application really needs the larger B680 motor.

The B660F is more attractive when higher speed and shorter motor length are important.

The B680D is the better choice when the machine requires more torque and power.

---

28. MPL-B680D-MJ72AA vs MPL-B640F-MJ72AA

The difference becomes especially important in machines with limited space.

The B640F is much shorter and lighter, while the B680D offers considerably greater torque capacity.

---

29. Why Choose the B680D-MJ72AA?

The MPL-B680D-MJ72AA makes sense when the machine needs a combination of:

• Approximately 9.3 kW output.
• Approximately 62.8 N·m continuous torque.
• Approximately 154.2 N·m peak torque.
• 2000 rpm rated speed.
• Multi-turn absolute feedback.
• Keyed shaft transmission.
• Large 215 mm frame.
• Long 203.2 mm motor stack.
• No integral brake.
• Industrial closed-loop servo control.

It is particularly attractive for machines where torque and precision are more important than compact size.

---

30. Where the No-Brake Version Makes Sense

The no-brake configuration is not necessarily a disadvantage.

For a horizontal axis, for example, there may be no requirement for a motor-mounted holding brake.

A separate mechanical brake may also be installed on the machine.

In some applications, the machine’s mechanical transmission is self-locking or otherwise capable of maintaining position without a motor brake.

The no-brake configuration can therefore be a sensible choice when the machine architecture does not require the motor itself to provide holding torque after servo power is removed.

---

31. Where a Brake Version Should Be Considered

A brake-equipped alternative should be considered when the motor drives:

• Vertical lifting equipment.
• Z-axis mechanisms.
• Elevated platforms.
• Gravity-loaded mechanisms.
• Vertical transfer systems.
• Lifting tables.
• Heavy suspended loads.

The brake should be designed as part of the complete motion-control and safety system rather than being considered an independent safety solution.

---

32. Installation Recommendations

Because the B680D is a large servo motor, installation requires more attention than a small-frame servo motor.

The mounting surface should be rigid and accurately aligned.

The motor flange should sit squarely against the machine mounting surface.

The driven shaft should be correctly aligned with the motor shaft.

The coupling should not impose excessive radial or axial force on the motor shaft.

The motor cables should also have adequate strain relief.

---

33. Servo Drive Matching

The motor should be matched with a compatible servo drive based on its complete electrical characteristics rather than simply matching the kW value.

Important selection factors include:

• 460 V-class operation.
• Continuous motor current.
• Peak motor current.
• Rated torque.
• Peak torque.
• 2000 rpm speed rating.
• Multi-turn feedback.
• Encoder protocol.
• Motor thermal characteristics.
• Brake status.
• Application duty cycle.
• Required acceleration.
• Required deceleration.
• Reflected load inertia.

A correctly sized drive is essential to obtain the expected performance from the B680D motor.

---

34. Load Inertia Considerations

The B680D can drive substantial mechanical loads, but load inertia must still be evaluated carefully.

The effective inertia seen by the motor depends on:

• Motor rotor inertia.
• Coupling inertia.
• Gearbox inertia.
• Screw inertia.
• Roller inertia.
• Pulley inertia.
• Load inertia.
• Gear ratio.

For a gearbox-driven application, the load inertia reflected back to the motor can be substantially reduced by an appropriate gear ratio.

However, excessive mechanical inertia can still lead to longer acceleration times and more difficult servo tuning.

---

35. Maintenance

The motor does not normally require extensive routine maintenance, but regular inspection is recommended.

Important points include:

• Motor mounting bolts.
• Coupling alignment.
• Shaft condition.
• Encoder cable.
• Power cable.
• Connector condition.
• Motor temperature.
• Vibration.
• Bearing noise.
• Servo-drive alarms.
• Feedback errors.
• Mechanical backlash.
• Abnormal operating noise.

Any significant increase in vibration or temperature should be investigated rather than simply resetting the servo drive and continuing operation.

---

36. Advantages in Heavy-Duty Automation

The B680D’s biggest practical advantage is its ability to provide high servo torque without giving up the feedback and control characteristics expected from a precision motion motor.

For example, a large positioning table may require considerable torque during acceleration, but it may still need to stop at precisely controlled positions.

A conventional motor can provide the power, but achieving the same level of closed-loop positioning and dynamic response may require additional equipment.

The MPL-B680D is designed specifically around this type of motion-control requirement.

---

37. Final Technical Comparison Table

---

38. Overall Evaluation

The MPL-B680D-MJ72AA is a strong choice for industrial motion systems that require high torque, high output power, precise feedback, and reliable servo control.

Its 215 mm frame, 203.2 mm stack, 2000 rpm rating, approximately 9.3 kW output, 62.8 N·m continuous stall torque, and 154.2 N·m peak stall torque place it firmly in the large industrial servo-motor category.

The multi-turn high-resolution absolute encoder is one of its most useful features, especially for large positioning systems where the motor may rotate through many revolutions during normal operation.

The keyed shaft provides a familiar mechanical interface for industrial couplings, gearboxes, pulleys, rollers, and other driven components.

The no-brake configuration is particularly appropriate for horizontal axes and applications where the machine does not require a motor-mounted holding brake. For gravity-loaded vertical applications, a brake-equipped alternative or an appropriate external holding system should be evaluated.

Overall, the MPL-B680D-MJ72AA is best suited to large, high-load, precision motion applications where approximately 9.3 kW of servo output and approximately 62.8 N·m of continuous torque are required, while maintaining accurate multi-turn absolute position feedback.