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

Allen-Bradley MPL-B320P-HK72AA Servo Motor

1. Product Introduction

The Allen-Bradley MPL-B320P-HK72AA is a low-inertia brushless AC rotary servo motor from the MP-Series MPL family. It is designed for industrial motion-control applications where high rotational speed, accurate feedback, rapid acceleration, and repeatable positioning are required.

The motor is a 460 V-class servo motor with a 100 mm frame, 50.8 mm magnet stack, 5000 rpm rated speed, and 2000-line incremental encoder. It uses a keyless shaft extension, a SpeedTEC DIN right-angle connector, and has no integral brake.

The HK72AA configuration is particularly useful where a machine requires incremental encoder feedback but does not require a keyed shaft or an integral holding brake. The keyless shaft arrangement allows the motor to be coupled using compatible clamp-style, shrink-disc, or other suitable coupling systems designed for a keyless shaft.

The motor belongs to the low-inertia MPL servo family. Its relatively low rotor inertia allows it to respond quickly to changes in commanded speed and position. This characteristic is valuable in machines that perform repeated indexing, acceleration, deceleration, reversing, and precise positioning.

The B320P motor configuration has a 5000 rpm speed rating, approximately 3.05 Nm continuous torque, approximately 1.5 kW continuous power, and approximately 7.8 × 10⁻⁵ kg·m² rotor inertia.

The exact model number is important when selecting a replacement because the HK72AA configuration differs from other B320P motors in several important areas, particularly the feedback system, shaft configuration, and brake arrangement.

2. Basic Product Parameters

Parameter	Specification
Model	MPL-B320P-HK72AA
Brand	Allen-Bradley
Series	MP-Series MPL
Product Family	MPL Low-Inertia Brushless Servo Motors
Product Type	AC Rotary Servo Motor
Motor Construction	Brushless Permanent-Magnet Servo Motor
Voltage Class	400 V AC class
Armature Voltage	460 V
Frame Size	3 / 100 mm
Magnet Stack Length	20 / 50.8 mm
Rated Speed	5000 rpm
Speed Class	5000 rpm
Continuous Rated Power	Approximately 1.5 kW
Continuous Torque	Approximately 3.05 Nm
Peak Torque	Approximately 7.91 Nm
Feedback	Incremental Encoder
Feedback Resolution	2000 lines/revolution
Shaft	Keyless Shaft Extension
Brake	No Integral Brake
Connector	SpeedTEC DIN
Connector Configuration	Right Angle
Connector Rotation	180° Rotatable
Mounting	IEC Metric
Mounting Holes	Free Mounting Holes / Type FF
Shaft Seal	No Shaft Seal
Rotor Inertia	Approximately 7.8 × 10⁻⁵ kg·m²
Frame Dimension	100 mm
Magnet Stack Dimension	50.8 mm
Approximate Weight	2.72 kg
Operating Temperature	Approximately 0 to 40 °C
Product Status	Discontinued

The published product information identifies the motor as a 460 V, 100 mm-frame, 50.8 mm-stack, 5000 rpm servo motor with a 2000-line incremental encoder, keyless shaft, right-angle rotatable DIN connector, and no brake.

The commonly listed reference weight is approximately 6.00 lb, or 2.72 kg.

3. Brand

Brand: Allen-Bradley

Allen-Bradley servo products are widely used in industrial automation and motion-control equipment.

The MPL-B320P-HK72AA belongs to a family of industrial servo motors intended to work with compatible servo drives and motion controllers.

For purchasing, maintenance, inventory, and replacement purposes, the complete catalog number should always be retained as MPL-B320P-HK72AA.

4. Product Series

Series: MP-Series MPL Low-Inertia Brushless Servo Motors

The MPL series is a family of permanent-magnet brushless AC servo motors designed for motion-control applications.

A major characteristic of this series is its low-inertia rotor construction. Low rotor inertia can help the motor respond quickly to changing commands, which is especially useful in applications involving frequent acceleration, deceleration, reversing, and indexing.

The MPL family includes multiple motor sizes and configurations.

Depending on the specific catalog number, the motor can have different:

• Frame sizes.
• Magnet stack lengths.
• Voltage classes.
• Feedback technologies.
• Shaft configurations.
• Brake options.
• Connector configurations.
• Speed ratings.

The MPL-B320P-HK72AA represents a particular combination of these characteristics: a 100 mm frame, 50.8 mm stack, 5000 rpm speed class, incremental encoder, keyless shaft, no brake, and rotatable right-angle connector.

5. Product Type

The MPL-B320P-HK72AA is a:

Brushless AC Rotary Servo Motor

It is intended to operate as part of a closed-loop servo system.

A typical servo system using this type of motor contains:

1. Servo motor.
2. Servo drive.
3. Motion controller.
4. Motor power cable.
5. Feedback cable.
6. Mechanical coupling.
7. Machine load.
8. Appropriate control and safety circuitry.

The encoder continuously provides rotational feedback to the servo system. The drive uses this information to regulate motor operation according to the commanded speed, torque, and position.

This makes the motor suitable for controlled motion rather than simple fixed-speed motor operation.

6. Model Number Explanation

The catalog number provides useful information about the motor configuration.

Model Code	Meaning
MPL	MPL low-inertia brushless servo motor family
B	400/460 V-class motor configuration
3	Frame size 3 / approximately 100 mm
20	50.8 mm magnet stack
P	5000 rpm speed class
H	Incremental encoder feedback
K	Keyless shaft configuration
7	SpeedTEC DIN connector configuration
2	No integral brake
AA	Catalog configuration designation

The K in the model number is particularly important because it identifies the keyless shaft.

The final 2 identifies the no-brake configuration.

Therefore, the complete H-K-7-2 configuration should be considered when selecting a replacement rather than looking only at the B320P portion of the model number.

7. Detailed Technical Specifications

Technical Parameter	Specification
Model	MPL-B320P-HK72AA
Motor Technology	Brushless permanent-magnet AC servo
Armature Voltage	460 V
Voltage Class	400 V AC
Rated Speed	5000 rpm
Frame Size	100 mm
Magnet Stack	50.8 mm
Continuous Torque	Approximately 3.05 Nm
Peak Torque	Approximately 7.91 Nm
Continuous Power	Approximately 1.5 kW
Rotor Inertia	Approximately 7.8 × 10⁻⁵ kg·m²
Feedback	Incremental encoder
Feedback Resolution	2000 lines/revolution
Shaft	Keyless
Brake	No brake
Connector	SpeedTEC DIN
Connector Style	Right angle
Connector Rotation	180° rotatable
Mounting	IEC Metric flange
Mounting Holes	Free mounting holes / Type FF
Shaft Seal	No shaft seal
Frame Dimension	100 mm
Stack Dimension	50.8 mm
Approximate Weight	2.72 kg
Operating Temperature	Approximately 0 to 40 °C

The B320P motor family is listed at approximately 1.5 kW, 3.05 Nm continuous torque, 7.91 Nm peak torque, and 7.8 × 10⁻⁵ kg·m² rotor inertia.

8. Dimensions and Weight

Dimensions are important when installing the motor into an existing machine.

The primary dimensional identifiers for the MPL-B320P-HK72AA are the 100 mm frame size and 50.8 mm magnet stack length.

The frame size should not be interpreted as the complete motor length.

The complete mechanical envelope includes the motor housing, mounting face, shaft area, rear section, feedback/connector area, and installation clearances.

Dimension Parameter	Specification
Model	MPL-B320P-HK72AA
Frame Size	100 mm
Frame Classification	Size 3
Magnet Stack Length	50.8 mm
Mounting Style	IEC Metric
Mounting Hole Type	Free Mounting Holes / Type FF
Shaft Type	Keyless
Shaft Seal	No shaft seal
Brake	No brake
Connector	SpeedTEC DIN
Connector Style	Right angle
Connector Rotation	180°
Approximate Weight	2.72 kg
Overall Motor Envelope	Verify exact mechanical drawing
Shaft Projection	Verify exact mechanical drawing
Mounting Clearance	Verify according to machine layout

The listed reference weight is approximately 6.00 lb / 2.72 kg.

For a replacement project, the complete mechanical drawing should be used to confirm the mounting-hole pattern, shaft dimensions, shaft projection, motor length, connector clearance, and any required installation space.

9. 100 mm Frame

The MPL-B320P-HK72AA uses a 100 mm frame.

The 100 mm frame provides a relatively compact motor body while allowing the B320P configuration to use a 50.8 mm active magnet stack.

This frame size is useful in industrial machines where available installation space is limited but the axis still requires a meaningful amount of continuous torque.

The metric mounting arrangement also makes the motor suitable for machine structures designed around metric mounting dimensions.

10. 50.8 mm Magnet Stack

The B320P configuration uses a 50.8 mm magnet stack, equivalent to approximately 2 inches.

The stack length is an important characteristic when comparing different MPL motors.

A longer active stack generally provides additional electromagnetic active length and supports a higher torque capability than a shorter stack within a comparable frame architecture.

For the B320P family, the 50.8 mm stack is associated with approximately 3.05 Nm continuous torque and approximately 7.91 Nm peak torque.

11. 5000 RPM Operation

The MPL-B320P-HK72AA has a 5000 rpm rated speed.

This speed rating makes it suitable for high-cycle automated machinery.

A 5000 rpm servo motor can provide rapid rotary movement, particularly when combined with a suitable gear ratio, coupling, or direct-drive mechanical arrangement.

Typical applications include:

• Packaging.
• Indexing.
• Pick-and-place.
• Material handling.
• Printing.
• Converting.
• Automated assembly.
• Rotary positioning.
• Feeding systems.
• High-speed machine axes.

The actual operating speed should be determined from the complete machine design, including load inertia, torque demand, coupling limits, acceleration requirements, and servo-drive capabilities.

12. Continuous Torque

The B320P motor configuration has approximately 3.05 Nm continuous torque.

Continuous torque is the important value when evaluating the motor’s ability to operate under a sustained load.

The actual continuous torque available in a machine can be affected by:

• Ambient temperature.
• Motor mounting.
• Duty cycle.
• Motor cooling.
• Operating speed.
• Drive configuration.
• Load profile.
• Machine enclosure.

For this reason, motor sizing should be based on the complete motion profile rather than simply selecting a motor from its nominal torque number.

13. Peak Torque

The B320P configuration is listed with approximately 7.91 Nm peak torque.

Peak torque is important during acceleration, deceleration, rapid positioning, and short-duration load changes.

For example, a machine axis may operate at a moderate torque level during steady movement but require a significantly higher torque during acceleration.

The peak torque capability gives the servo system additional short-duration torque capacity for such dynamic operating conditions.

The exact usable peak torque depends on the drive, motor temperature, duty cycle, speed, and duration of the torque demand.

14. Rated Power

The B320P family is listed at approximately 1.5 kW continuous rated power.

Power should be considered together with torque and speed.

A servo axis that operates at high speed may require relatively little torque but still produce significant mechanical power.

A different axis may require higher torque at lower speed.

Therefore, selecting the motor based only on the 1.5 kW rating is not sufficient. The complete speed-torque profile of the machine should be evaluated.

15. Incremental Encoder Feedback

The MPL-B320P-HK72AA uses a 2000-line incremental encoder.

The encoder provides feedback about motor shaft movement to the servo drive.

The drive uses this feedback to control the motor’s position and speed.

Incremental feedback is particularly appropriate for systems where the control architecture supports encoder pulse feedback and where machine homing or reference establishment is part of the operating sequence.

Typical applications include:

• Indexing axes.
• Rotary positioning.
• Conveyor synchronization.
• Packaging machinery.
• Automated assembly.
• Pick-and-place mechanisms.
• High-speed positioning systems.

16. Keyless Shaft

The keyless shaft is one of the most important mechanical features of the HK72AA configuration.

A keyless shaft does not use a traditional shaft key and keyway for torque transmission.

Instead, the motor can be coupled through an appropriately designed friction-locking or clamp-style mechanical connection.

This can provide a clean mechanical interface and can be useful in applications where the coupling is specifically designed for a keyless servo shaft.

The keyless configuration should be checked carefully during replacement because a keyed motor and keyless motor are not automatically mechanically interchangeable.

17. No Integral Brake

The MPL-B320P-HK72AA is configured with no integral brake.

This can simplify the motor configuration for horizontal axes and other applications that do not require a motor-mounted holding brake.

The absence of a brake also means that the motor should not be relied upon to hold a gravity-loaded axis after power is removed.

For vertical or suspended loads, the machine may require another appropriate holding mechanism depending on the application and safety design.

18. SpeedTEC DIN Connector

The motor uses a SpeedTEC DIN connector in a right-angle configuration.

The connector is specified as 180° rotatable.

This provides useful flexibility when routing motor cables around the machine.

A rotatable right-angle connector can be particularly helpful where there is limited clearance behind the motor.

During installation, the cable should be routed without excessive bending, pulling, twisting, or mechanical strain.

19. Rotor Inertia

The B320P configuration has approximately 7.8 × 10⁻⁵ kg·m² rotor inertia.

Rotor inertia is an important servo-motor parameter because it influences acceleration and deceleration response.

A low-inertia motor can change speed quickly when sufficient torque is available.

This is particularly useful in applications with frequent:

• Starts.
• Stops.
• Direction changes.
• Indexing.
• Position corrections.
• High-speed acceleration.

However, the motor’s rotor inertia is only one part of the machine’s total inertia.

The reflected inertia of the driven load, gearbox, pulley, screw, coupling, rotary table, conveyor, or tooling must also be considered.

20. Electrical Parameters

Electrical Parameter	Specification
Model	MPL-B320P-HK72AA
Armature Voltage	460 V
Voltage Class	400 V AC
Rated Speed	5000 rpm
Continuous Power	Approximately 1.5 kW
Continuous Torque	Approximately 3.05 Nm
Peak Torque	Approximately 7.91 Nm
Feedback	Incremental encoder
Encoder Resolution	2000 lines/revolution
Brake	No brake
Shaft	Keyless
Connector	SpeedTEC DIN
Connector Style	Right angle
Connector Rotation	180°
Rotor Inertia	Approximately 7.8 × 10⁻⁵ kg·m²
Frame	100 mm
Stack	50.8 mm
Weight	Approximately 2.72 kg

The B320P electrical performance values are associated with the 5000 rpm motor family configuration.

21. Mechanical Parameters

Mechanical Parameter	Specification
Model	MPL-B320P-HK72AA
Frame Size	100 mm
Magnet Stack	50.8 mm
Mounting	IEC Metric
Mounting Hole Style	Free Mounting Holes / Type FF
Shaft	Keyless
Shaft Seal	No shaft seal
Brake	No brake
Connector	SpeedTEC DIN
Connector Direction	Right angle
Connector Rotation	180°
Approximate Weight	2.72 kg
Frame Dimension	100 mm
Stack Dimension	50.8 mm
Complete Motor Envelope	Confirm exact mechanical drawing
Shaft Projection	Confirm exact mechanical drawing
Installation Clearance	Confirm according to machine design

The keyless shaft and no-shaft-seal configuration are specifically associated with the HK72AA model.

22. Operating Environment

The motor should be installed in an environment suitable for its specified operating conditions.

A commonly listed operating temperature range for this configuration is approximately 0 to 40 °C.

The installation should also be evaluated for:

• Ambient temperature.
• Humidity.
• Dust.
• Oil.
• Coolant.
• Vibration.
• Mechanical shock.
• Cable routing.
• Motor ventilation.
• Mounting orientation.
• Contamination.

The motor should have adequate airflow and heat dissipation.

The motor should not be enclosed in a way that prevents the heat generated during operation from being removed effectively.

23. Typical Applications

Packaging Machinery

The MPL-B320P-HK72AA can be used in packaging equipment requiring fast and repeatable rotary motion.

Possible functions include:

• Film feeding.
• Product indexing.
• Cutting.
• Sealing.
• Conveyor synchronization.
• Rotary positioning.

The high-speed capability and incremental encoder make the motor suitable for repeated machine cycles.

Material Handling

Material-handling equipment often requires controlled acceleration and precise positioning.

The motor can be used for:

• Conveyor indexing.
• Transfer mechanisms.
• Roller drives.
• Positioning axes.
• Automated handling systems.

The keyless shaft can be integrated with suitable couplings designed for friction-locking shaft connections.

Pick-and-Place Systems

Pick-and-place equipment frequently requires rapid acceleration and deceleration.

The low-inertia construction is useful for this type of application because the motor is designed to respond quickly to changes in motion commands.

Rotary Indexing Equipment

Rotary indexing machines require accurate and repeatable movement between defined positions.

The MPL-B320P-HK72AA can be used for rotary tables, indexing wheels, feeders, and other controlled rotary axes.

Printing and Converting

Printing and converting equipment may require synchronized rotary motion.

Servo motors can be used for:

• Feed rollers.
• Cutting rollers.
• Positioning mechanisms.
• Web handling.
• Rotary indexing.
• Synchronization axes.

Automated Assembly

Automated assembly equipment can use servo motors for precise positioning and repeated machine movements.

Typical applications include:

• Component positioning.
• Feeding.
• Rotary indexing.
• Inspection positioning.
• Tool positioning.
• Automated assembly axes.

Machine Tools

The motor can also be used for selected machine-tool auxiliary axes and automated positioning systems where the speed, torque, feedback, and mechanical interface are appropriate.

24. Main Product Advantages

24.1 Low-Inertia Construction

The MPL family’s low-inertia design provides a responsive motor platform for dynamic servo applications.

This is useful for machines that repeatedly accelerate, decelerate, or reverse.

24.2 5000 rpm Speed Rating

The 5000 rpm rating supports high-speed motion.

This can be useful in production equipment where short cycle times and rapid rotary movement are important.

24.3 3.05 Nm Continuous Torque

The approximately 3.05 Nm continuous torque rating provides a useful output capability for medium-duty servo axes.

The 50.8 mm stack contributes to the motor’s torque capability within the B320P family.

24.4 7.91 Nm Peak Torque

The approximately 7.91 Nm peak torque capability provides additional torque for short-duration acceleration and dynamic machine movements.

24.5 Incremental Encoder

The 2000-line incremental encoder provides closed-loop feedback.

It is suitable for servo-drive systems designed around incremental feedback.

24.6 Keyless Shaft

The keyless shaft provides a clean mechanical interface for suitable friction-locking couplings.

It can be advantageous when the machine has been designed around keyless mechanical connections.

24.7 No Brake

The no-brake configuration keeps the motor mechanically simple for applications that do not require an integral holding brake.

It can be appropriate for many horizontal axes and continuously controlled rotary applications.

24.8 Compact 100 mm Frame

The 100 mm frame provides a relatively compact package while maintaining the B320P motor’s torque and speed capabilities.

24.9 Rotatable Right-Angle Connector

The 180° rotatable connector can simplify cable routing.

This is useful when the motor is installed close to machine frames, guards, linear guides, or other components.

25. Five Related Models from the Same MPL Series

The following models are closely related to the MPL-B320P-HK72AA.

They are useful for comparison, but a related model should not automatically be considered a direct replacement because feedback, shaft, brake, or other configuration details can be different.

Related Model	Frame / Stack	Speed	Feedback	Shaft	Brake	Main Difference	Dimensions / Weight
MPL-B320P-HJ72AA	100 mm / 50.8 mm	5000 rpm	Incremental encoder	Keyed	No brake	Keyed instead of keyless shaft	100 mm frame; 50.8 mm stack; verify exact weight
MPL-B320P-HJ74AA	100 mm / 50.8 mm	5000 rpm	Incremental encoder	Keyed	24 V DC	Keyed shaft and integral brake	100 mm frame; 50.8 mm stack; verify exact weight
MPL-B320P-HK74AA	100 mm / 50.8 mm	5000 rpm	Incremental encoder	Keyless	24 V DC	Adds integral brake	100 mm frame; 50.8 mm stack; verify exact weight
MPL-B320P-SK72AA	100 mm / 50.8 mm	5000 rpm	Single-turn high-resolution	Keyless	No brake	Different feedback system	100 mm frame; 50.8 mm stack; verify exact weight
MPL-B320P-SK74AA	100 mm / 50.8 mm	5000 rpm	Single-turn high-resolution	Keyless	24 V DC	Different feedback plus brake	100 mm frame; 50.8 mm stack; verify exact weight

These related configurations demonstrate the principal options around the B320P motor family.

26. Same-Series Comparison

Model	Frame	Stack	Speed	Feedback	Shaft	Brake	Weight / Dimensions
MPL-B320P-HK72AA	100 mm	50.8 mm	5000 rpm	Incremental	Keyless	No	Approx. 2.72 kg; 100 mm frame / 50.8 mm stack
MPL-B320P-HJ72AA	100 mm	50.8 mm	5000 rpm	Incremental	Keyed	No	Approx. 3.6 kg class; verify exact model
MPL-B320P-HK74AA	100 mm	50.8 mm	5000 rpm	Incremental	Keyless	24 V DC	Verify exact weight; 100 mm frame / 50.8 mm stack
MPL-B320P-SK72AA	100 mm	50.8 mm	5000 rpm	Single-turn high-resolution	Keyless	No	Verify exact weight; 100 mm frame / 50.8 mm stack
MPL-B320P-SK74AA	100 mm	50.8 mm	5000 rpm	Single-turn high-resolution	Keyless	24 V DC	Verify exact weight; 100 mm frame / 50.8 mm stack

The HK72AA is distinguished primarily by the combination of incremental feedback + keyless shaft + no brake.

27. Five Same-Brand Commonly Encountered Models

Model	Series	Voltage Class	Frame / Stack	Speed	Feedback	Shaft	Brake	Dimensions / Weight
MPL-B210V-VJ72AA	MPL Low-Inertia Servo	400/460 V class	Smaller MPL frame	High-speed class	High-resolution feedback	Keyed	No brake	Smaller MPL frame; exact dimensions and weight to be verified
MPL-B220T-VJ72AA	MPL Low-Inertia Servo	400/460 V class	Mid-size MPL configuration	High-speed class	High-resolution feedback	Keyed	No brake	Exact frame, stack and weight to be verified
MPL-B230P-VJ72AA	MPL Low-Inertia Servo	400/460 V class	100 mm-class configuration	5000 rpm class	High-resolution feedback	Keyed	No brake	Exact envelope and weight to be verified
MPL-B320P-SJ72AA	MPL Low-Inertia Servo	400/460 V class	100 mm / 50.8 mm	5000 rpm	Single-turn high-resolution	Keyed	No brake	100 mm frame; 50.8 mm stack; exact weight to be verified
MPL-B330P-MJ72AA	MPL Low-Inertia Servo	400/460 V class	Larger MPL configuration	5000 rpm class	Multi-turn high-resolution	Keyed	No brake	Larger MPL frame; exact dimensions and weight to be verified

These models represent different sizes and feedback configurations within the broader MPL product family.

28. HK72AA Compared With HJ72AA

The HK72AA and HJ72AA are extremely close in electrical and performance characteristics.

The major difference is the shaft.

Parameter	MPL-B320P-HK72AA	MPL-B320P-HJ72AA
Frame	100 mm	100 mm
Magnet Stack	50.8 mm	50.8 mm
Speed	5000 rpm	5000 rpm
Continuous Torque	Approx. 3.05 Nm	Approx. 3.05 Nm
Power	Approx. 1.5 kW	Approx. 1.5 kW
Feedback	2000-line incremental	2000-line incremental
Shaft	Keyless	Keyed
Brake	No brake	No brake
Connector	SpeedTEC DIN	SpeedTEC DIN
Weight	Approx. 2.72 kg	Verify exact model weight
Frame / Stack Dimensions	100 mm / 50.8 mm	100 mm / 50.8 mm

The choice between these configurations is therefore strongly influenced by the mechanical shaft interface.

29. HK72AA Compared With HK74AA

The HK72AA and HK74AA retain the keyless shaft and incremental encoder arrangement, while the major difference is the brake.

Parameter	MPL-B320P-HK72AA	MPL-B320P-HK74AA
Frame	100 mm	100 mm
Stack	50.8 mm	50.8 mm
Speed	5000 rpm	5000 rpm
Feedback	Incremental encoder	Incremental encoder
Shaft	Keyless	Keyless
Brake	No brake	24 V DC brake
Connector	SpeedTEC DIN	SpeedTEC DIN
Main Difference	No integral brake	Integral holding brake
Weight	Approx. 2.72 kg	Verify exact configuration
Dimensions	100 mm frame / 50.8 mm stack	100 mm frame / 50.8 mm stack

For applications where the axis must hold position after servo power is removed, the brake-equipped configuration may be considered during the engineering selection process.

30. HK72AA Compared With SK72AA

The HK72AA and SK72AA can have very similar mechanical characteristics because both use the keyless shaft and no-brake configuration.

The major difference is the feedback system.

Parameter	MPL-B320P-HK72AA	MPL-B320P-SK72AA
Frame	100 mm	100 mm
Stack	50.8 mm	50.8 mm
Speed	5000 rpm	5000 rpm
Shaft	Keyless	Keyless
Brake	No brake	No brake
Feedback	Incremental encoder	Single-turn high-resolution
Connector	SpeedTEC DIN	SpeedTEC DIN
Main Difference	Incremental feedback	Single-turn high-resolution feedback
Weight	Approx. 2.72 kg	Verify exact configuration
Dimensions	100 mm frame / 50.8 mm stack	100 mm frame / 50.8 mm stack

The two configurations should therefore be checked carefully against the servo drive and motion-control architecture before considering a substitution.

31. HK72AA Compared With HJ74AA

The HJ74AA has both a keyed shaft and an integral brake, while the HK72AA has a keyless shaft and no brake.

Parameter	MPL-B320P-HK72AA	MPL-B320P-HJ74AA
Frame	100 mm	100 mm
Stack	50.8 mm	50.8 mm
Speed	5000 rpm	5000 rpm
Feedback	Incremental encoder	Incremental encoder
Shaft	Keyless	Keyed
Brake	No brake	24 V DC
Connector	SpeedTEC DIN	SpeedTEC DIN
Continuous Torque	Approx. 3.05 Nm	Approx. 3.05 Nm
Power	Approx. 1.5 kW	Approx. 1.5 kW
Weight	Approx. 2.72 kg	Approx. 5.44 kg reference
Main Difference	Keyless / no brake	Keyed / brake-equipped

This comparison highlights why the complete catalog number is important during replacement.

32. Application Selection

The MPL-B320P-HK72AA can be considered for applications where the following characteristics are required:

• High-speed servo movement.
• Incremental encoder feedback.
• Keyless shaft connection.
• No motor-mounted brake.
• Approximately 3.05 Nm continuous torque.
• Approximately 1.5 kW continuous power.
• 5000 rpm operating capability.
• Compact 100 mm frame.
• 50.8 mm magnet stack.
• Rapid acceleration and deceleration.

This combination is particularly relevant to horizontal servo axes and other applications where a motor-mounted brake is not part of the mechanical design.

33. Servo Tuning Considerations

Servo tuning should be performed with the entire machine considered as one mechanical system.

Important factors include:

Parameter	Engineering Importance
Motor Inertia	Defines the motor’s basic dynamic response
Load Inertia	Determines the total inertia seen by the motor
Gear Ratio	Changes reflected load inertia
Coupling Stiffness	Influences servo response
Mechanical Backlash	Can affect positioning accuracy
Friction	Influences low-speed operation
Acceleration	Determines required peak torque
Deceleration	Determines peak torque and regenerative demand
Maximum Speed	Determines high-speed operating limits
Resonance	Can restrict servo gain
Duty Cycle	Determines thermal loading
Load Profile	Determines actual motor sizing requirement

A low-inertia servo motor can provide rapid response, but correct tuning remains necessary to achieve stable positioning and smooth operation.

34. Installation Considerations

The motor mounting surface should be clean, rigid, and properly aligned.

The mounting face should not have burrs, debris, paint buildup, or other material that could prevent the motor from seating correctly.

The keyless shaft requires an appropriate mechanical coupling.

The coupling should be correctly installed and tightened according to its own mechanical requirements.

The motor should not be subjected to excessive radial or axial shaft loads.

Cable routing should provide adequate clearance around the rotatable connector.

The motor should also have sufficient airflow and thermal dissipation.

35. Maintenance Considerations

Routine inspection can help identify mechanical or electrical problems before they affect machine operation.

Recommended inspection areas include:

• Motor mounting bolts.
• Shaft coupling.
• Keyless shaft interface.
• Bearing condition.
• Motor temperature.
• Connector condition.
• Feedback cable.
• Motor power cable.
• Grounding.
• Cable shielding.
• Excessive vibration.
• Unusual motor noise.
• Oil or coolant contamination.
• Dust accumulation.

Because the motor does not contain an integral brake, brake inspection is not required for the motor itself, although any external holding or safety brake should be maintained according to its own requirements.

36. Replacement Checklist

Replacement Check	Requirement
Model	MPL-B320P-HK72AA
Voltage	460 V
Voltage Class	400 V AC
Frame	100 mm
Stack	50.8 mm
Speed	5000 rpm
Continuous Torque	Approx. 3.05 Nm
Continuous Power	Approx. 1.5 kW
Peak Torque	Approx. 7.91 Nm
Feedback	2000-line incremental encoder
Shaft	Keyless
Brake	No integral brake
Connector	SpeedTEC DIN
Connector Style	Right angle
Connector Rotation	180°
Mounting	IEC Metric
Weight	Approx. 2.72 kg
Frame Dimension	100 mm
Stack Dimension	50.8 mm
Shaft Seal	No shaft seal
Drive Compatibility	Must be verified
Feedback Compatibility	Must be verified
Mechanical Coupling	Must be compatible with keyless shaft
Cable Configuration	Must be verified

This checklist can be used when comparing the existing motor with a replacement motor before ordering.

37. Product Advantages at a Glance

Feature	Practical Advantage
100 mm Frame	Compact servo package for industrial machine axes
50.8 mm Stack	Provides useful torque capability
5000 rpm	Suitable for high-speed motion
3.05 Nm Continuous Torque	Supports medium-duty continuous servo loads
7.91 Nm Peak Torque	Provides additional short-duration dynamic torque
1.5 kW Class Power	Suitable for many industrial motion applications
2000-Line Encoder	Provides incremental closed-loop feedback
Keyless Shaft	Compatible with suitable friction-locking couplings
No Brake	Simplified configuration for unbraked axes
Low Rotor Inertia	Supports rapid acceleration and deceleration
SpeedTEC DIN Connector	Compact industrial motor connection
180° Rotatable Connector	Provides flexible cable routing
Metric Mounting	Suitable for metric machine structures
Approx. 2.72 kg Weight	Relatively manageable motor mass

38. Five Related Model Parameters

Model	Frame	Stack	Speed	Feedback	Shaft	Brake	Continuous Torque	Power	Dimensions / Weight
MPL-B320P-HJ72AA	100 mm	50.8 mm	5000 rpm	Incremental	Keyed	No	Approx. 3.05 Nm	Approx. 1.5 kW	100 mm / 50.8 mm; verify weight
MPL-B320P-HJ74AA	100 mm	50.8 mm	5000 rpm	Incremental	Keyed	24 V DC	Approx. 3.05 Nm	Approx. 1.5 kW	100 mm / 50.8 mm; approx. 5.44 kg reference
MPL-B320P-HK74AA	100 mm	50.8 mm	5000 rpm	Incremental	Keyless	24 V DC	Approx. 3.05 Nm	Approx. 1.5 kW	100 mm / 50.8 mm; verify weight
MPL-B320P-SK72AA	100 mm	50.8 mm	5000 rpm	Single-turn high-resolution	Keyless	No	B320P class	Approx. 1.5 kW class	100 mm / 50.8 mm; verify weight
MPL-B320P-SK74AA	100 mm	50.8 mm	5000 rpm	Single-turn high-resolution	Keyless	24 V DC	B320P class	Approx. 1.5 kW class	100 mm / 50.8 mm; verify weight

These models provide a practical reference set for comparing feedback type, shaft configuration, and brake requirements.

39. Five Same-Brand Model Parameters

Model	Series	Voltage Class	Frame / Stack	Speed	Feedback	Shaft	Brake	Dimensions / Weight
MPL-B210V-VJ72AA	MPL Low-Inertia Servo	400/460 V class	Smaller MPL frame	High-speed class	High-resolution feedback	Keyed	No brake	Smaller frame; exact dimensions and weight to be verified
MPL-B220T-VJ72AA	MPL Low-Inertia Servo	400/460 V class	Mid-size MPL frame	High-speed class	High-resolution feedback	Keyed	No brake	Exact frame / stack / weight to be verified
MPL-B230P-VJ72AA	MPL Low-Inertia Servo	400/460 V class	100 mm-class	5000 rpm class	High-resolution feedback	Keyed	No brake	Exact envelope / weight to be verified
MPL-B320P-SJ72AA	MPL Low-Inertia Servo	400/460 V class	100 mm / 50.8 mm	5000 rpm	Single-turn high-resolution	Keyed	No brake	100 mm / 50.8 mm; exact weight to be verified
MPL-B330P-MJ72AA	MPL Low-Inertia Servo	400/460 V class	Larger MPL configuration	5000 rpm class	Multi-turn high-resolution	Keyed	No brake	Larger frame; exact dimensions and weight to be verified

40. Practical Engineering Advantages

The MPL-B320P-HK72AA combines several characteristics that make it suitable for industrial servo applications.

The 100 mm frame keeps the physical motor package relatively compact.

The 50.8 mm magnet stack provides a useful torque capability within the B320P family.

The 5000 rpm speed allows fast rotary motion.

The 2000-line incremental encoder provides the feedback needed for closed-loop servo operation.

The keyless shaft offers a mechanical interface suitable for compatible friction-locking couplings.

The absence of an integral brake keeps the motor configuration straightforward for applications that do not need motor-mounted holding capability.

The low-inertia construction is useful when the machine performs repeated acceleration and deceleration.

41. Important Points Before Replacement

When replacing an existing MPL-B320P-HK72AA, the following points should be checked carefully:

Voltage

The replacement motor should have the correct voltage class.

Frame Size

The mounting interface should match the existing 100 mm frame arrangement.

Magnet Stack

The 50.8 mm stack should be confirmed when maintaining the same motor performance class.

Feedback

The replacement must support the required incremental encoder feedback architecture.

Shaft

The existing machine must be compatible with a keyless shaft.

Brake

The machine should not expect an integral brake if replacing this exact no-brake configuration.

Connector

The SpeedTEC DIN connector and cable arrangement should be checked.

Drive

The servo drive must be compatible with the motor’s feedback and electrical characteristics.

Mechanical Load

The load inertia and torque requirements should be reviewed.

Dimensions

The complete mechanical envelope must be checked rather than relying only on the 100 mm frame designation.

42. Overall Technical Summary

The Allen-Bradley MPL-B320P-HK72AA is a 460 V-class, 100 mm-frame, 50.8 mm-stack, 5000 rpm low-inertia brushless AC servo motor.

Its main configuration consists of:

• 460 V armature voltage.
• 100 mm frame.
• 50.8 mm magnet stack.
• 5000 rpm speed.
• Approximately 3.05 Nm continuous torque.
• Approximately 7.91 Nm peak torque.
• Approximately 1.5 kW continuous power.
• Approximately 7.8 × 10⁻⁵ kg·m² rotor inertia.
• 2000-line incremental encoder.
• Keyless shaft.
• No integral brake.
• SpeedTEC DIN right-angle connector.
• 180° rotatable connector.
• IEC metric mounting.
• Approximately 2.72 kg reference weight.

The principal product characteristics are consistent with the published B320P/HK72AA configuration.

43. Final Product Description

The Allen-Bradley MPL-B320P-HK72AA is a high-speed, low-inertia servo motor designed for industrial automation systems that require controlled, repeatable, and responsive rotary motion.

Its 100 mm frame, 50.8 mm magnet stack, and 5000 rpm speed rating provide a compact package for high-cycle motion applications.

The motor’s approximately 3.05 Nm continuous torque and approximately 7.91 Nm peak torque make it suitable for a range of medium-duty servo axes, while the approximately 1.5 kW continuous power class provides useful output for automated machinery.

The 2000-line incremental encoder provides feedback for closed-loop servo control.

The keyless shaft distinguishes this model from the keyed HJ72AA configuration and should be matched with an appropriate mechanical coupling.

The no-brake configuration makes the motor suitable for applications that do not require an integral motor holding brake.

The right-angle SpeedTEC DIN connector with 180° rotation provides additional flexibility for motor cable routing in compact machine installations.

The approximate reference weight of 2.72 kg also makes the motor relatively manageable for machine installation and replacement work.

For replacement purposes, the complete model number should be checked rather than selecting a motor solely by power, torque, frame size, or speed. The feedback type, shaft configuration, brake arrangement, connector, voltage, and mechanical envelope all affect interchangeability.

Overall, the MPL-B320P-HK72AA is a specialized B320P configuration combining 5000 rpm operation, low-inertia servo response, incremental encoder feedback, keyless shaft construction, 100 mm metric mounting, and a no-brake design. It is particularly applicable to high-speed automated machinery, positioning systems, indexing equipment, packaging machines, material-handling systems, and other industrial motion-control applications where fast and repeatable servo movement is required.