Introduction

The MPL-A420P-SJ74AA belongs to Allen-Bradley's MP-Series MPL family of low-inertia brushless servo motors. It is engineered for motion systems that require accurate feedback, fast response, and reliable operation over repeated machine cycles.

The motor uses a 115 mm frame with a 50.8 mm magnet stack and supports speeds up to 5000 RPM. Its low-inertia characteristics make it well suited to dynamic applications in which the axis repeatedly changes speed or position.

Position information is provided by a single-turn high-resolution absolute encoder. The encoder uses 1024 Sin/Cos cycles per revolution and Hiperface communication, giving the servo control system detailed feedback for closed-loop positioning and speed regulation.

The 24 V DC holding brake is another useful feature of this particular configuration. It can provide mechanical holding when the servo axis is stopped or the drive is disabled, subject to the application's braking requirements and control sequence.

For mechanical integration, the motor provides an IEC metric mounting arrangement, keyed shaft, and right-angle SpeedTEC DIN connector. The connector's 180° rotation capability gives machine designers additional flexibility when routing motor and feedback cables.

Technical Specifications

Specification	Details
Brand	Allen-Bradley
Product Family	MP-Series MPL
Model	MPL-A420P-SJ74AA
Product Type	Low-Inertia Brushless AC Rotary Servo Motor
Voltage	230 V AC
Voltage Class	200 V AC
Frame Size	115 mm
Magnet Stack Length	50.8 mm
Maximum Speed	5000 RPM
Continuous Torque	4.74 N·m
Peak Torque	10.2 N·m
Continuous Power	2 kW
Feedback	Absolute Single-Turn High-Resolution Encoder
Feedback Resolution	1024 Sin/Cos cycles/rev
Feedback Protocol	Hiperface
Shaft Type	Keyed Shaft Extension
Brake	24 V DC Holding Brake
Connector	SpeedTEC DIN, Right Angle
Connector Rotation	180° Rotatable
Mounting	IEC Metric, Free Mounting Holes
Shaft Seal	No Shaft Seal
Weight	4.30 kg (9.48 lb)

Recommended Related Models

For applications requiring similar Allen-Bradley MP-Series MPL servo motor configurations, the following models are suitable related options:

Allen-Bradley MPL-A420P-SJ72AA — similar 115 mm frame, 50.8 mm magnet stack and single-turn high-resolution feedback configuration.
Allen-Bradley MPL-A420P-MJ72AA — related 230 V MPL servo motor using multi-turn high-resolution absolute feedback.
Allen-Bradley MPL-A420P-MJ74AA — closely related A420P configuration with multi-turn feedback and keyed shaft.
Allen-Bradley MPL-A420P-MK74AA — related A420P servo motor configuration with keyless shaft and multi-turn high-resolution feedback.

Popular Related Models

Allen-Bradley MPL-A420P-SJ72AA
Allen-Bradley MPL-A420P-MJ72AA
Allen-Bradley MPL-A420P-MJ74AA
Allen-Bradley MPL-A420P-MK74AA
Allen-Bradley MPL-A420P-MK72AA
Allen-Bradley MPL-A430P-MK74AA

Applications

The MPL-A420P-SJ74AA is designed for machine axes where precise closed-loop motion and responsive speed control are important.

Common applications include:

Packaging and labeling equipment
Automated assembly machines
Material handling systems
Pick-and-place machinery
Printing and converting equipment
Electronic manufacturing equipment
Precision indexing systems
Machine tools
Automated inspection machinery
High-speed production equipment
Robotics and auxiliary motion axes

Its low-inertia design is particularly useful for applications with repeated acceleration, deceleration, indexing, and positioning movements.

Advantages

High-speed servo operation
With a maximum speed of 5000 RPM, the motor can support high-cycle applications where rapid rotary movement is required.

Low-inertia construction
The MPL Series is designed around low rotor inertia, allowing the motor to respond quickly to changes in commanded motion and helping improve dynamic performance.

Single-turn absolute feedback
The integrated high-resolution single-turn encoder provides precise rotor-position feedback for closed-loop motion control.

Integrated holding brake
A 24 V DC brake is included in this configuration, providing additional holding capability for applications where the motor shaft needs to remain stationary when the servo is not actively driving.

Keyed shaft design
The keyed shaft extension provides a conventional mechanical connection for compatible couplings and driven components.

Flexible connector positioning
The right-angle SpeedTEC DIN connector can be rotated through 180°, helping simplify cable routing in confined machine installations.

Compact 115 mm frame
The Frame 4 / 115 mm configuration provides a relatively compact mechanical package while retaining the performance characteristics expected from an industrial servo motor.

Technical FAQs

1. What type of motor is the MPL-A420P-SJ74AA?
It is a low-inertia brushless AC rotary servo motor belonging to the Allen-Bradley MP-Series MPL family.

2. What voltage class does the MPL-A420P-SJ74AA use?
The motor is a 230 V AC / 200 V class servo motor intended for use with compatible Allen-Bradley servo drive systems.

3. What is the maximum speed of this servo motor?
The specified maximum speed is 5000 RPM.

4. What type of feedback does the MPL-A420P-SJ74AA provide?
It uses a single-turn high-resolution absolute encoder with 1024 Sin/Cos cycles per revolution and Hiperface protocol.

5. Does the MPL-A420P-SJ74AA include a brake?
Yes. This model includes a 24 V DC holding brake.

6. Is the shaft keyed or keyless?
The MPL-A420P-SJ74AA has a keyed shaft extension.

7. What is the magnet stack length?
The motor uses a 50.8 mm magnet stack, corresponding to stack length 20 in the MPL product configuration.

8. What is the continuous torque rating?
The specified continuous output torque is approximately 4.74 N·m, with a peak torque capability of approximately 10.2 N·m.

9. What type of connector is used?
The motor uses a SpeedTEC DIN right-angle connector that can be rotated through 180° for flexible installation and cable routing.

10. Which factors should be checked before connecting the motor to a servo drive?
Check the motor-drive compatibility, voltage class, feedback type, brake requirements, motor wiring, grounding, mechanical coupling, and servo tuning parameters before commissioning.

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