Brand:Allen Bradley PLC Item No.:MPL-A420P-HJ74AA Product Origin:USA Product Dimensions:Frame Size: 115 mm Product Weight:4.3 kg Payment:T/T, Western Union, Credit Card Goods_stock:15 Shipping Port:Xiamen, China Lead Time:1-3 Days Condition:Brand New And Original Warranty:1 Year Certificate:COO
The Allen Bradley MPL-A420P-HJ74AA Servo Motor is a low-inertia brushless AC servo motor designed for industrial motion applications where responsive movement and accurate feedback are essential. It belongs to the MP-Series MPL family and uses a 115 mm frame, making it suitable for machinery that requires a capable servo motor while maintaining a controlled mechanical footprint.
In high-cycle automation, servo motors are frequently required to accelerate, decelerate, reverse, and reposition within a short period. Packaging machines, assembly systems, indexing equipment, and automated handling mechanisms can place significant demands on the motor's dynamic response.
A low-inertia servo motor can help address these requirements by allowing the rotor to respond quickly to changes in commanded speed. This is particularly valuable when reducing unnecessary motion delay is important to overall machine productivity.
The HJ74AA configuration also includes a 24 V DC holding brake. This is a useful feature for machine designs where the shaft needs to remain stationary when servo torque is removed. Applications involving vertical loads or controlled positioning should still be evaluated as a complete mechanical system, with the brake treated as a holding device rather than the primary stopping mechanism.
The keyed shaft provides a familiar mechanical connection for compatible machine components, while the right-angle connector arrangement can help simplify cable routing in compact equipment.
For maintenance teams, accurate catalog-number matching is essential. MPL-A420P motors can have similar frame dimensions while differing in feedback, shaft design, brake configuration, connector arrangement, and other characteristics. Selecting a replacement solely by frame size can therefore create compatibility problems.
The MPL-A420P-HJ74AA is well suited to industrial motion systems that require responsive servo performance, accurate feedback, integrated shaft holding, and dependable compatibility with the appropriate Allen Bradley motion-control architecture.
Technical Specifications
Specification
Details
Brand
Allen Bradley
Manufacturer
Rockwell Automation
Product Family
MP-Series MPL
Model
MPL-A420P-HJ74AA
Product Type
AC Servo Motor
Motor Type
Low-Inertia Brushless Servo Motor
Voltage Class
230 V AC
Frame Size
115 mm
Frame
4
Magnet Stack
Configuration Specific
Feedback
Servo Feedback
Shaft Type
Keyed Shaft Extension
Brake
24 V DC Holding Brake
Connector
Right-Angle Industrial Servo Connector
Mounting
Metric Mounting
Weight
4.30 kg (9.48 lb)
Overall Dimensions
Not supplied
Application
Industrial Motion Control
Weight: 4.30 kg (9.48 lb)
The supplied product information specifies a 115 mm frame size and 4.30 kg weight. Complete overall motor dimensions and additional electrical characteristics were not provided, so unsupported values have not been added.
Recommended Related Models
For Allen Bradley MP-Series MPL servo applications, the following models are useful related references:
Allen Bradley MPL-A420P-HJ72AA – Servo Motor
Allen Bradley MPL-A420P-HK72AA – Servo Motor
Allen Bradley MPL-A420P-HK74AA – Servo Motor
Allen Bradley MPL-A420P-MJ72AA – Servo Motor
Allen Bradley MPL-A420P-SJ72AA – Servo Motor
These models belong to closely related MPL-A420P configurations, but feedback, shaft, brake, connector, and electrical characteristics can vary between catalog numbers. Compatibility should therefore be confirmed before replacement.
Popular Related Models
For customers maintaining Allen Bradley motion-control systems, the following MP-Series servo motors are also useful related products:
Allen Bradley MPL-A420P-HJ72AA – Servo Motor
Allen Bradley MPL-A420P-HK72AA – Servo Motor
Allen Bradley MPL-A420P-HK74AA – Servo Motor
Allen Bradley MPL-A420P-MJ72AA – Servo Motor
Allen Bradley MPL-A330P-SJ74AA – Servo Motor
When sourcing the Allen Bradley MPL-A420P-HJ74AA Servo Motor, always provide the complete catalog number. The HJ74AA configuration is important because the motor's 115 mm frame, keyed shaft, feedback arrangement, connector configuration, and 24 V DC holding-brake characteristics must match the installed servo drive and mechanical system for reliable operation.
Applications
The Allen Bradley MPL-A420P-HJ74AA Servo Motor is a low-inertia brushless AC servo motor developed for industrial motion-control applications where fast response, accurate positioning, and repeatable operation are essential.
With a 115 mm frame size, the motor is well suited to automated machinery that requires a practical balance between dynamic performance and mechanical installation space. Its low-inertia design is especially valuable in applications involving frequent acceleration, deceleration, indexing, and rapid position changes.
Typical applications include:
Automated assembly machines
Packaging and labeling equipment
Pick-and-place systems
Material handling machinery
Machine tools
Printing and converting equipment
Electronics manufacturing systems
Precision indexing equipment
Automated production lines
Industrial positioning equipment
High-cycle machinery
Servo motor replacement projects
The MPL-A420P-HJ74AA is a strong choice for motion systems where the servo motor must repeatedly respond to changing commands while maintaining stable and repeatable machine movement.
Advantages
Low-inertia dynamic response
The MPL-A420P-HJ74AA is designed for applications requiring rapid changes in motor speed. Its low-inertia construction can help the motor respond efficiently to acceleration and deceleration commands.
High-speed servo performance
The motor is suitable for motion applications where fast rotational movement is important to machine productivity and cycle time.
Precision feedback capability
Its servo feedback system allows the motion controller to continuously monitor motor position and speed, supporting closed-loop operation.
115 mm frame size
The 115 mm frame provides a compact industrial package for applications that require greater motor capability without using an unnecessarily large mechanical envelope.
230 V class platform
The motor is designed for compatible 230 V-class Allen Bradley servo-drive systems.
Keyed shaft configuration
The keyed shaft provides a conventional mechanical interface for compatible couplings, pulleys, and other driven machine components.
Integrated holding brake
The HJ74AA configuration includes a 24 V DC holding brake, providing shaft-holding capability when the servo motor is not actively producing torque.
Flexible connector arrangement
The right-angle connector arrangement can make cable routing easier in compact machine layouts and help simplify installation.
Strong replacement value
For compatible MP-Series installations, the MPL-A420P-HJ74AA provides a practical replacement option when maintaining an existing servo architecture is more efficient than redesigning the entire motion system.
Technical FAQs
1. What is the Allen Bradley MPL-A420P-HJ74AA?
The MPL-A420P-HJ74AA is a low-inertia brushless AC servo motor from the Allen Bradley MP-Series MPL family, designed for industrial motion-control applications.
2. What voltage class is associated with this motor?
The MPL-A420P-HJ74AA is designed for the 230 V AC servo-motor class and must be paired with a compatible servo drive.
3. What is the frame size of the MPL-A420P-HJ74AA?
The motor uses a 115 mm frame size.
4. Does this motor include a holding brake?
Yes. The HJ74AA configuration includes a 24 V DC holding brake.
5. What is the benefit of a low-inertia servo motor?
Low rotor inertia allows the motor to change speed rapidly, which is useful for high-cycle positioning, indexing, and applications with frequent acceleration and deceleration.
6. What can cause excessive servo-motor vibration?
Possible causes include incorrect servo tuning, mechanical resonance, coupling misalignment, unstable feedback, mounting problems, excessive load, or bearing deterioration.
7. What can cause a servo motor to overheat?
Excessive load, high duty cycle, mechanical binding, inadequate cooling, aggressive acceleration profiles, or incorrect drive configuration can increase motor temperature.
8. What should be checked when the motor does not rotate?
Check the servo enable condition, active drive alarms, motor power connections, feedback wiring, brake release, motion commands, drive parameters, and mechanical restrictions.
9. How should the integrated brake be used?
The brake is primarily intended for shaft holding when the servo is disabled. It should not normally be treated as the primary method of dynamic machine stopping.
10. What should be verified before replacing an existing MPL servo motor?
Confirm the complete catalog number, frame size, feedback arrangement, shaft configuration, brake option, connector arrangement, voltage class, and compatibility with the installed servo drive and controller.
