Product Overview for High-Speed Motion Systems

The Allen-Bradley MPL-A320P-HJ74AA is a high-speed member of the MP-Series MPL low-inertia servo motor family. Its 100 mm frame makes it suitable for machine designs where a relatively compact motor is needed without sacrificing the responsiveness required for high-cycle automation.

The motor is designed for a maximum speed of 5000 rpm, making it particularly useful in applications where rapid rotary motion contributes directly to production efficiency. Its approximately 2.24 N·m rated torque complements this high-speed operating profile.

Closed-loop feedback is provided through a high-resolution single-turn encoder. The encoder works with the servo controller to provide continuous information about motor position and speed, allowing the control system to correct motion and maintain the commanded trajectory.

The integrated holding brake distinguishes the HJ74AA configuration from comparable no-brake versions. This provides additional flexibility for applications where the motor shaft must remain stationary after the servo system removes driving power. Vertical-axis applications should receive particular attention because the brake must be appropriately sized for the load and used as intended.

The motor's keyless shaft extension provides compatibility with suitable keyless coupling arrangements. The IEC metric mounting configuration also supports straightforward integration into machine structures designed around standard metric dimensions.

Cable management is helped by the right-angle SpeedTEC DIN connector, which can be rotated through 180 degrees. This is useful in compact machine assemblies where the motor cable path must avoid moving components or fit within a restricted enclosure.

For manufacturers building fast, repetitive machinery, the MPL-A320P-HJ74AA provides a combination of high-speed capability, low inertia, precise feedback, and mechanical holding functionality in one servo motor package.

Technical Specifications

Parameter	Specification
Brand	Allen-Bradley
Manufacturer	Rockwell Automation
Model	MPL-A320P-HJ74AA
Product Family	MP-Series MPL
Product Type	AC Rotary Servo Motor
Motor Design	Low-Inertia Brushless Servo Motor
Voltage Class	240 V AC
Armature Voltage	230 V
Frame Size	100 mm
Magnet Stack Length	50.8 mm
Maximum Speed	5000 rpm
Rated Torque	Approximately 2.24 N·m
Feedback	Single-Turn High-Resolution Encoder
Encoder Type	1024 Sin/Cos
Shaft Configuration	Keyless Shaft Extension
Brake	Integrated Holding Brake
Connector	SpeedTEC DIN Connector
Connector Position	Right Angle, 180° Rotatable
Mounting	IEC Metric, Free Mounting Holes
Mounting Flange	100 mm Bolt Circle
Frame Dimension	100 mm
Weight	3.70 kg (8.16 lb)

When installing the MPL-A320P-HJ74AA, particular attention should be given to the brake circuit and encoder connections in addition to the normal motor power wiring. Shaft alignment and coupling installation are also important, especially when the motor is operated at high speed.

Recommended Related Models

Model	Product Type	Relationship
Allen-Bradley MPL-A320P-HH72AA	MP-Series Servo Motor	Closely related high-speed no-brake configuration
Allen-Bradley MPL-A320P-HJ72AA	MP-Series Servo Motor	Similar high-speed configuration without brake
Allen-Bradley MPL-A320H-SK74AA	MP-Series Servo Motor	Related 100 mm motor with holding brake
Allen-Bradley MPL-A320H-SK72AA	MP-Series Servo Motor	Related low-inertia no-brake configuration
Allen-Bradley MPL-A430P-SK72AA	MP-Series Servo Motor	Higher-capacity MPL servo motor

When selecting a replacement, the full catalog number should be checked carefully. A motor with the same frame size may have a different speed rating, encoder arrangement, brake configuration, or shaft design and therefore may not be a direct substitute.

Popular Related MP-Series Servo Motors

Model	Product Family	Typical Application
Allen-Bradley MPL-A310P-MK74AA	MP-Series MPL	Compact high-speed automation
Allen-Bradley MPL-A320H-SK72AA	MP-Series MPL	Low-inertia positioning
Allen-Bradley MPL-A320H-SK74AA	MP-Series MPL	Servo axes requiring holding capability
Allen-Bradley MPL-A320P-HH72AA	MP-Series MPL	High-speed machine motion
Allen-Bradley MPL-A320P-HJ72AA	MP-Series MPL	High-speed positioning and indexing
Allen-Bradley MPL-A320P-HJ74AA	MP-Series MPL	High-speed servo motion with holding brake
Allen-Bradley MPL-A430P-SK72AA	MP-Series MPL	Higher-capacity industrial motion systems

The Allen-Bradley MPL-A320P-HJ74AA MP-Series Servo Motor combines a compact 100 mm frame with low-inertia construction, high-resolution encoder feedback, 5000 rpm maximum speed, and an integrated holding brake. This combination makes it particularly well suited to fast indexing, packaging, assembly, and other automated machine applications where rapid response and controlled shaft holding are both important.

Industrial Applications

The Allen-Bradley MPL-A320P-HJ74AA is a high-speed, low-inertia AC servo motor from the MP-Series MPL family. It is intended for automated machinery where rapid acceleration, controlled positioning, and repeatable motion are essential to machine performance. With a 100 mm frame, the motor provides a compact package for machine axes where installation space is limited but responsive servo performance is still required.

This model can be considered for packaging machinery, indexing systems, automated assembly equipment, material-handling machines, printing and converting equipment, machine tools, and other high-cycle production systems. Its high-speed characteristics are particularly useful when machine throughput depends on rapid rotary movement and short positioning cycles.

The motor operates as part of a closed-loop motion system. Its high-resolution encoder supplies feedback to the compatible servo drive, allowing the controller to monitor actual shaft movement and continuously adjust the motor according to the commanded motion profile.

A built-in holding brake further expands the possible application range. Compared with no-brake MPL configurations, the MPL-A320P-HJ74AA can provide additional mechanical holding capability when the servo axis is not energized, provided the brake is used within its intended operating conditions.

For OEM machine builders, the combination of a high-speed rotor, low inertia, encoder feedback, and integrated brake makes this motor an attractive choice for demanding automated motion systems.

Engineering Strengths of the MPL-A320P-HJ74AA

The motor's low-inertia design is particularly valuable in high-cycle applications. Lower rotor inertia allows the servo system to accelerate and decelerate the motor more quickly, helping machine axes respond rapidly to changing position or speed commands.

With a maximum speed of 5000 rpm, the MPL-A320P-HJ74AA is suited to applications where higher rotational speed can contribute to shorter machine cycles. Its approximately 2.24 N·m rated torque provides a balanced performance profile for compact, high-speed servo axes.

The integrated single-turn high-resolution encoder provides accurate feedback to the servo drive. This feedback is essential for maintaining closed-loop control and allows the system to identify the actual position and speed of the motor during operation.

The holding brake is another important distinction. When the servo amplifier is not supplying motor power, the brake can be used to hold the shaft stationary in suitable applications. This feature can be valuable for certain vertical axes and mechanisms where uncontrolled movement after power removal must be prevented.

Mechanical installation is also designed with machine builders in mind. The motor uses a keyless shaft extension, while the right-angle SpeedTEC DIN connector can be rotated through 180 degrees. This makes it easier to adapt cable routing and motor orientation to the available machine space.

Overall, the MPL-A320P-HJ74AA combines the speed advantages of a high-performance MPL motor with the added functionality of a holding brake, providing a flexible solution for automated motion equipment.

Technical FAQs

1. What type of motor is the MPL-A320P-HJ74AA?

The MPL-A320P-HJ74AA is an Allen-Bradley MP-Series MPL low-inertia AC rotary servo motor. It is designed for closed-loop motion-control applications requiring accurate speed, torque, and position regulation.

2. What is the maximum speed of the MPL-A320P-HJ74AA?

The motor has a maximum speed of 5000 rpm. The actual operating speed must be coordinated with the compatible servo drive, mechanical transmission, load, and machine duty cycle.

3. Does this servo motor include a holding brake?

Yes. The HJ74AA configuration includes a holding brake. The brake provides mechanical shaft holding when used according to its intended operating conditions.

4. What feedback device is used by this motor?

The motor uses a single-turn high-resolution encoder. Encoder feedback allows the servo controller to monitor actual motor position and speed for closed-loop operation.

5. What is the approximate rated torque?

The MPL-A320P-HJ74AA provides approximately 2.24 N·m rated torque. Proper motor sizing should also consider peak torque, load inertia, acceleration, friction, and the required operating duty cycle.

6. Can the holding brake be used for emergency stopping?

The holding brake should not automatically be considered a dynamic emergency stopping device. Emergency stopping must be designed according to the machine's safety architecture and applicable requirements, with the servo drive and mechanical braking strategy evaluated as a complete system.

7. What shaft configuration does this motor use?

The motor uses a keyless shaft extension. The coupling should be compatible with the shaft design and properly sized for the torque and operating conditions of the application.

8. What is the purpose of the rotatable motor connector?

The right-angle SpeedTEC DIN connector can be rotated through 180 degrees, providing additional flexibility when routing motor and feedback cables through a machine cabinet or around mechanical components.

9. What should be verified before commissioning the motor?

Verify the servo drive compatibility, motor catalog number, motor parameters, encoder feedback, brake wiring, motor power connections, grounding, coupling alignment, and motion-control settings. The motor and drive should be configured as a matched servo system.

10. Why might a servo axis fail to hold its position after the motor is disabled?

Possible causes include incorrect brake wiring, improper brake sequencing, insufficient brake holding capability for the load, mechanical movement, incorrect drive configuration, or a brake that has not been properly released or engaged. The electrical brake circuit and mechanical load should both be checked.

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