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Allen-Bradley MPL-B320P-SJ72AA Servo Motor

1. Product Overview

The Allen-Bradley MPL-B320P-SJ72AA is a low-inertia brushless AC servo motor designed for industrial motion-control applications that require accurate positioning, rapid acceleration, controlled deceleration, and repeatable high-speed operation.

It belongs to the MP-Series MPL low-inertia servo motor family and uses a 460 V class electrical design, a 100 mm frame, and a 50.8 mm magnetic stack. The motor is rated for 5000 rpm operation and provides approximately 1.5 kW of continuous output power with approximately 3.05 N·m of continuous torque and approximately 7.91 N·m of peak torque.

The SJ72AA configuration is particularly identifiable by its single-turn high-resolution encoder, keyed shaft, SpeedTEC DIN right-angle connector, and no integrated brake. It uses an IEC metric mounting arrangement with free mounting holes of Type FF.

This motor is intended to operate as part of a complete servo system. In normal use, the motor is paired with a compatible servo drive, feedback interface, motion controller, power cable, feedback cable, and the appropriate mechanical transmission.

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2. Brand and Product Series

Item	Specification
Brand	Allen-Bradley
Product Family	MP-Series
Product Series	MPL Low-Inertia Servo Motors
Product Type	Brushless AC synchronous rotary servo motor
Model	MPL-B320P-SJ72AA
Voltage Class	460 V AC / 400 V class
Frame Size	100 mm
Magnetic Stack	50.8 mm / 2.0 in
Speed Class	5000 rpm
Feedback	Single-turn high-resolution encoder
Shaft	Keyed shaft
Brake	No brake
Connector	SpeedTEC DIN
Connector Style	Right-angle, rotatable
Mounting	IEC metric flange
Mounting Holes	Free mounting holes, Type FF
Motor Construction	Low-inertia permanent-magnet servo motor

The MPL family is designed around low-inertia motor construction. The purpose of this design is to provide a fast dynamic response when the motor is commanded to accelerate, decelerate, reverse, or move to a new position.

The B320P size sits in the 100 mm frame class and uses a 50.8 mm magnetic stack. This gives the motor a useful combination of compact physical size, torque output, and high-speed capability.

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3. Model Number Explanation

Understanding the catalog number is useful when selecting a replacement motor because several MPL motors can have similar external appearances while using different feedback systems, shaft configurations, or brake options.

Code	Meaning
MPL	Low-inertia servo motor family
B	460 V-class motor family
3	100 mm frame class
20	50.8 mm magnetic stack
P	5000 rpm speed class
S	Single-turn high-resolution encoder
J	Keyed shaft
7	SpeedTEC DIN right-angle connector, rotatable
2	No brake
AA	Standard catalog configuration

The complete model number is therefore much more informative than simply identifying the motor as a “B320P.”

For example, changing SJ72AA to SJ74AA changes the brake configuration, while changing SJ72AA to SK72AA changes the shaft configuration. Changing the feedback designation can also change the encoder technology.

This is why the complete catalog number should be checked whenever the motor is being replaced.

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4. Main Technical Parameters

Parameter	Specification
Model	MPL-B320P-SJ72AA
Product Type	Rotary servo motor
Motor Construction	Low-inertia brushless AC synchronous
Voltage Class	460 V AC
Rated Power	Approx. 1.5 kW
Continuous Torque	Approx. 3.05 N·m
Peak Torque	Approx. 7.91 N·m
Rated Speed	5000 rpm
Maximum Speed	5000 rpm
Frame Size	100 mm / 3.94 in
Magnetic Stack Length	50.8 mm / 2.0 in
Feedback	Single-turn high-resolution encoder
Feedback Resolution	Sin/Cos, 1024 cycles/rev
Feedback Protocol	Hiperface-type absolute feedback
Shaft	Keyed shaft extension
Shaft Seal	No shaft seal
Brake	No integral brake
Connector	SpeedTEC DIN
Connector Position	Right angle
Connector Rotation	180° rotatable
Mounting	IEC metric flange
Mounting Holes	Free mounting holes, Type FF
Rotor Inertia	Approx. 7.8 × 10⁻⁵ kg·m²
Weight	Approx. 4.5 kg
Overall Dimensions	Approx. 42.8 × 21.7 × 26.0 cm, B320P-family envelope
Operating Temperature Class	Up to approximately 40 °C under standard conditions

The published technical data identifies the motor as a 5000 rpm, 1.5 kW, 3.05 N·m continuous-torque motor with approximately 7.91 N·m peak torque and approximately 7.8 × 10⁻⁵ kg·m² rotor inertia. The B320P family is associated with a 100 mm frame and 50.8 mm magnetic stack.

The 4.5 kg figure is a useful catalog-level reference for the B320P configuration. Actual packaged or distributor-listed weight can differ depending on how the product is measured and whether accessories or packaging are included.

The overall dimensions should be treated as a B320P-family installation envelope rather than a substitute for the exact mechanical drawing. The 100 mm frame and 50.8 mm stack are the more important standardized mechanical identifiers.

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5. Electrical and Performance Specifications

Parameter	Value
Model	MPL-B320P-SJ72AA
Armature Voltage Class	460 V AC
Continuous Output	Approx. 1.5 kW
Continuous Torque	Approx. 3.05 N·m
Peak Torque	Approx. 7.91 N·m
Rated Speed	5000 rpm
Maximum Speed	5000 rpm
Rotor Inertia	Approx. 0.000078 kg·m²
Frame Size	100 mm
Magnetic Stack	50.8 mm
Weight	Approx. 4.5 kg
Dimensions	Approx. 42.8 × 21.7 × 26.0 cm family envelope

The combination of relatively low rotor inertia and 5000 rpm operating capability makes the B320P suitable for machine axes that repeatedly accelerate and decelerate.

The approximately 3.05 N·m continuous torque rating is particularly important for determining whether the motor can carry the continuous mechanical load. The peak torque figure should be considered separately because acceleration and short-duration overload requirements are different from continuous running conditions.

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6. Feedback System

The MPL-B320P-SJ72AA uses a single-turn high-resolution encoder.

The feedback device continuously provides the servo control system with information about motor position and movement. This information is used by the servo drive to regulate speed, position, acceleration, and torque.

The encoder is specified as a high-resolution Sin/Cos feedback device with approximately 1024 cycles per revolution and absolute single-turn functionality.

The single-turn arrangement is useful when the application requires accurate position information within one mechanical revolution.

For applications where absolute position must be retained across multiple revolutions without returning to a reference point, a multi-turn configuration may be more appropriate. In that situation, another MPL model with the appropriate multi-turn feedback should be considered.

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7. Shaft Configuration

The MPL-B320P-SJ72AA has a keyed shaft extension.

A keyed shaft provides a positive mechanical interface between the servo motor and the machine’s coupling, pulley, gear, or other driven component.

The keyway is particularly useful when the machine is already designed around conventional keyed mechanical components.

The shaft should not be subjected to excessive radial or axial forces. Coupling alignment is also important because misalignment can increase bearing loading, vibration, heat generation, and mechanical wear.

The motor is specified without an integral shaft seal in its standard configuration. Therefore, the mechanical environment around the shaft should be considered carefully when the motor is installed in areas exposed to dust, liquid, coolant, or other contaminants.

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8. Brake Configuration

The MPL-B320P-SJ72AA does not include an integral motor brake.

This is one of the main differences between the SJ72AA and SJ74AA versions.

The absence of a brake can be beneficial in applications where a holding brake is not required. It can also simplify the electrical design because there is no brake coil that needs to be controlled.

However, applications involving vertical axes or loads that can move when the servo is disabled may require a separate mechanical holding solution or a motor configuration with an integrated brake.

The machine designer should never assume that the absence of a motor brake is acceptable simply because the servo drive can control the motor position. Holding requirements should be evaluated separately from normal servo positioning.

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9. Connector Configuration

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

The connector can be rotated through approximately 180 degrees, providing greater flexibility when routing motor cables.

This is particularly useful in compact machinery where a straight connector could interfere with guards, machine frames, cable trays, or neighboring components.

The connector arrangement is also useful for standardized servo installations because the cable direction can be adjusted according to the available installation space.

Correct connector engagement is essential. Poor connections can result in intermittent power delivery, feedback faults, encoder errors, drive trips, or unstable servo operation.

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10. Mounting Configuration

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

The 100 mm frame size is one of the defining mechanical characteristics of the B320P motor.

Mechanical Parameter	Specification
Model	MPL-B320P-SJ72AA
Frame Size	100 mm
Frame Class	Frame 3
Magnetic Stack	50.8 mm
Mounting Type	Flange mount
Flange Standard	IEC metric
Mounting Hole Style	Free mounting holes, Type FF
Shaft	Keyed
Shaft Seal	No
Connector	Right-angle SpeedTEC DIN
Connector Rotation	180°
Weight	Approx. 4.5 kg
Dimensions	Approx. 42.8 × 21.7 × 26.0 cm family envelope

Before installing a replacement motor, the flange pattern, shaft diameter, shaft extension, keyway, connector clearance, and overall motor envelope should all be checked.

A motor with the same 100 mm frame size is not automatically a direct mechanical replacement.

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11. Product Introduction

The MPL-B320P-SJ72AA is designed for industrial machinery where conventional motor control is not sufficient and precise closed-loop motion control is required.

The motor converts electrical power from the servo drive into controlled mechanical rotation. The encoder returns position information to the control system, allowing the drive to continuously correct the motor’s movement.

This closed-loop arrangement is especially useful in machinery that repeatedly performs the same movement.

For example, a packaging machine may need to move a product a precise distance, stop, accelerate again, and repeat the process hundreds or thousands of times during a production cycle.

A servo motor such as the B320P is designed for this type of controlled operation.

The motor’s 5000 rpm speed rating also makes it suitable for applications where the axis must move quickly between positions.

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12. Low-Inertia Motor Characteristics

One of the defining characteristics of the MPL series is its low-inertia rotor design.

The rotor inertia of the B320P is approximately 7.8 × 10⁻⁵ kg·m².

Low rotor inertia means that the motor itself presents relatively low rotational resistance during acceleration and deceleration.

This can be useful when the machine requires:

• Rapid acceleration
• Rapid deceleration
• Frequent reversing
• Short positioning cycles
• High indexing frequency
• Fast speed changes
• Precise synchronization

The actual servo response still depends on the mechanical load, reflected inertia, transmission ratio, servo tuning, load friction, and controller settings.

Low motor inertia by itself does not guarantee a fast machine. The complete mechanical system must be properly matched.

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13. Product Advantages

13.1 High-Speed 5000 rpm Operation

The 5000 rpm speed rating gives the motor sufficient rotational speed for many high-cycle industrial machines.

High motor speed can also allow machine designers to use suitable transmission ratios to achieve the required linear or rotary output speed.

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13.2 1.5 kW Output Class

The approximately 1.5 kW continuous power rating makes the B320P suitable for a broad range of medium-duty motion-control applications.

It provides more output capability than smaller MPL motor sizes while retaining the compact 100 mm frame class.

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13.3 3.05 N·m Continuous Torque

The continuous torque rating of approximately 3.05 N·m gives the motor a useful continuous mechanical output level.

This is important for applications where the servo axis must maintain torque for extended periods rather than simply producing short acceleration peaks.

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13.4 Approximately 7.91 N·m Peak Torque

The peak torque capability provides additional short-duration torque for acceleration and transient load conditions.

This can be useful when the machine has significant acceleration requirements or experiences temporary increases in mechanical load.

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13.5 Low Rotor Inertia

The low rotor inertia helps the motor respond quickly to changes in commanded motion.

This characteristic is valuable for indexing and positioning equipment where the motor repeatedly changes speed.

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13.6 High-Resolution Encoder

The single-turn high-resolution encoder provides detailed position feedback.

This allows the servo system to perform accurate closed-loop speed and position control.

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13.7 Keyed Shaft

The keyed shaft is convenient for traditional couplings and mechanical transmissions.

It can simplify integration with machinery that already uses keyed shafts and hubs.

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13.8 No Integral Brake

Although a brake can be necessary in certain applications, not having a brake can also be advantageous where the axis does not require mechanical holding.

It eliminates the brake coil and brake-control wiring from the motor configuration.

This can simplify the machine’s electrical architecture.

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13.9 Rotatable Right-Angle Connector

The 180° rotatable right-angle connector provides greater freedom during machine installation.

This can be especially useful when several motors are installed close together.

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13.10 Compact 100 mm Frame

The 100 mm frame is relatively compact for a 1.5 kW, 5000 rpm servo motor.

This makes the motor easier to integrate into machinery where installation space is limited.

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14. Typical Applications

Packaging Machinery

The motor can be used for packaging-machine axes such as product indexing, feeder mechanisms, sealing systems, cutters, rotary positioning mechanisms, and synchronized transport.

The combination of high speed and feedback makes it useful for machines with repeated short motion cycles.

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Automated Assembly

Automated assembly machines frequently use servo motors for positioning and transfer mechanisms.

The B320P can be applied to indexing tables, transfer mechanisms, actuator systems, rotary stations, and other controlled axes.

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Material Handling

Servo-controlled material-handling equipment can use this type of motor for positioning conveyors, indexing systems, transfer units, and synchronized transport mechanisms.

The final selection should be based on load torque, acceleration, duty cycle, and reflected inertia.

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Printing Machinery

Printing equipment requires accurate coordination between rotating components.

Servo motors can be used for registration, roller synchronization, positioning, indexing, and controlled speed adjustment.

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Converting Equipment

Converting machines often use servo motors for cutting, feeding, indexing, tension-related mechanisms, and synchronized rotary movement.

The high-speed characteristics of the B320P can be useful for high-cycle converting machinery.

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Labeling Equipment

Labeling systems require precise synchronization between product movement and labeling mechanisms.

The high-resolution encoder can provide the feedback necessary for repeatable positioning and speed coordination.

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Electronics Manufacturing

Electronics production equipment frequently uses servo motors for component positioning, indexing, inspection fixtures, feeders, and automated transfer mechanisms.

The low-inertia characteristics are useful when the machine must repeatedly move small loads at high speed.

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Inspection and Test Equipment

Servo motors can be used for controlled movement of inspection fixtures, rotary tables, camera mechanisms, sensors, and test components.

The encoder feedback helps the machine maintain repeatable positions.

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15. Application Summary

Application	Typical Function	Relevant Motor Feature
Packaging	Indexing and positioning	5000 rpm, encoder feedback
Assembly	Transfer and positioning	Low inertia
Material Handling	Conveyor indexing	Fast response
Printing	Registration and synchronization	High-resolution feedback
Converting	Cutting and feeding	High-speed operation
Labeling	Product synchronization	Position feedback
Electronics Manufacturing	Component positioning	Low-inertia response
Inspection Equipment	Fixture positioning	Closed-loop feedback
Rotary Indexing	Repeated positioning	5000 rpm capability
Machine Automation	General servo axis	1.5 kW output class

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16. Installation and Engineering Considerations

The MPL-B320P-SJ72AA should be selected according to the complete motion profile rather than motor power alone.

The continuous torque requirement should be calculated from the actual mechanical load.

The acceleration and deceleration requirements should also be considered because the required peak torque can be significantly higher than the continuous running torque.

Load inertia is another important consideration.

A servo motor can operate correctly at a particular torque level but still perform poorly if the reflected load inertia is poorly matched to the motor.

The transmission ratio should therefore be considered during machine design.

Couplings, gearboxes, belts, pulleys, lead screws, and other mechanical components all affect the effective load seen by the servo motor.

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17. Maintenance Recommendations

The motor should be inspected periodically as part of normal machine maintenance.

Important inspection points include:

• Motor temperature
• Abnormal vibration
• Bearing noise
• Shaft condition
• Coupling alignment
• Mounting-bolt tightness
• Encoder cable condition
• Power cable condition
• Connector condition
• Mechanical backlash
• Servo following error
• Repeated drive faults
• Abnormal acceleration or deceleration
• Unexpected motor heating

If repeated encoder errors occur, the encoder cable and connector should be checked before replacing the motor.

Likewise, if excessive vibration occurs, the coupling and driven mechanical system should be inspected rather than assuming the motor itself is defective.

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18. Five Closely Related Models

The following models belong to the same MPL B320P family or are very closely related configurations. The main differences are feedback type, shaft arrangement, and brake configuration.

Model	Feedback	Shaft	Brake	Speed	Power	Continuous Torque	Frame	Stack	Weight	Dimensions
MPL-B320P-SJ74AA	Single-turn high-resolution encoder	Keyed	24 V DC	5000 rpm	Approx. 1.5 kW	Approx. 3.05 N·m	100 mm	50.8 mm	Approx. 4.5 kg class	Approx. 42.8 × 21.7 × 26.0 cm family envelope
MPL-B320P-SK72AA	Single-turn high-resolution encoder	Keyless	No brake	5000 rpm	Approx. 1.5 kW	Approx. 3.05 N·m	100 mm	50.8 mm	Approx. 4.5 kg class	Approx. 42.8 × 21.7 × 26.0 cm family envelope
MPL-B320P-SK74AA	Single-turn high-resolution encoder	Keyless	24 V DC	5000 rpm	Approx. 1.5 kW	Approx. 3.05 N·m	100 mm	50.8 mm	Approx. 4.5 kg class	Approx. 42.8 × 21.7 × 26.0 cm family envelope
MPL-B320P-MJ72AA	Multi-turn high-resolution encoder	Keyed	No brake	5000 rpm	Approx. 1.5 kW	Approx. 3.05 N·m	100 mm	50.8 mm	Approx. 4.5–5.1 kg class	Approx. 42.8 × 21.7 × 26.0 cm family envelope
MPL-B320P-MJ74AA	Multi-turn high-resolution encoder	Keyed	24 V DC	5000 rpm	Approx. 1.5 kW	Approx. 3.05 N·m	100 mm	50.8 mm	Approx. 4.5–5.1 kg class	Approx. 42.8 × 21.7 × 26.0 cm family envelope

These configurations are part of the same general B320P platform. The existence of the SJ72AA, SJ74AA, SK72AA, SK74AA, MJ72AA, and MJ74AA configurations is consistent with the B320P product family structure.

The SJ72AA is the no-brake keyed-shaft version, while the SJ74AA adds a 24 V DC holding brake.

The SK versions use a keyless shaft, which can be useful for specific coupling arrangements.

The MJ versions use multi-turn high-resolution feedback rather than the single-turn feedback used by the SJ configuration.

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19. Related Model Comparison

Feature	MPL-B320P-SJ72AA	MPL-B320P-SJ74AA	MPL-B320P-SK72AA	MPL-B320P-SK74AA	MPL-B320P-MJ72AA
Motor Family	MPL	MPL	MPL	MPL	MPL
Frame	100 mm	100 mm	100 mm	100 mm	100 mm
Magnetic Stack	50.8 mm	50.8 mm	50.8 mm	50.8 mm	50.8 mm
Speed	5000 rpm	5000 rpm	5000 rpm	5000 rpm	5000 rpm
Power	Approx. 1.5 kW	Approx. 1.5 kW	Approx. 1.5 kW	Approx. 1.5 kW	Approx. 1.5 kW
Continuous Torque	Approx. 3.05 N·m	Approx. 3.05 N·m	Approx. 3.05 N·m	Approx. 3.05 N·m	Approx. 3.05 N·m
Feedback	Single-turn encoder	Single-turn encoder	Single-turn encoder	Single-turn encoder	Multi-turn encoder
Shaft	Keyed	Keyed	Keyless	Keyless	Keyed
Brake	No	24 V DC	No	24 V DC	No
Connector	SpeedTEC DIN	SpeedTEC DIN	SpeedTEC DIN	SpeedTEC DIN	SpeedTEC DIN
Weight	Approx. 4.5 kg	Approx. 4.5 kg class	Approx. 4.5 kg class	Approx. 4.5 kg class	Approx. 4.5–5.1 kg class
Dimensions	Approx. B320P envelope	Approx. B320P envelope	Approx. B320P envelope	Approx. B320P envelope	Approx. B320P envelope

The five configurations illustrate an important point: the basic motor capacity can remain similar while the feedback and mechanical options change significantly.

For an existing machine, the feedback type and shaft configuration can be just as important as the motor’s power rating.

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20. Five Representative Same-Brand Models

Rather than treating “popular” as a formal ranking, the following are five representative same-brand models that are useful for comparison across different MPL motor sizes and configurations.

Model	Power	Continuous Torque	Speed	Frame	Stack	Feedback	Shaft	Brake	Weight	Dimensions
MPL-B310P-SJ72AA	Approx. 0.77 kW	Approx. 1.58 N·m	5000 rpm	100 mm	25.4 mm	Single-turn encoder	Keyed	No	Approx. 2.4 kg	B310P family envelope
MPL-B320P-SJ72AA	Approx. 1.5 kW	Approx. 3.05 N·m	5000 rpm	100 mm	50.8 mm	Single-turn encoder	Keyed	No	Approx. 4.5 kg	B320P family envelope
MPL-B330P-SJ72AA	Approx. 1.8 kW	Approx. 4.18 N·m	5000 rpm	100 mm	76.2 mm	Single-turn encoder	Keyed	No	Approx. 6.1 kg	B330P family envelope
MPL-B420P-SJ72AA	Approx. 1.9 kW	Approx. 4.74 N·m	5000 rpm	115 mm	50.8 mm	Single-turn encoder	Keyed	No	Approx. 6.4 kg	B420P family envelope
MPL-B430P-SJ72AA	Approx. 2.2 kW	Approx. 6.55 N·m	5000 rpm	115 mm class	Longer stack	Single-turn encoder	Keyed	No	Approx. 9.2 kg	B430P family envelope

These models illustrate how the MPL family changes as the required motor output increases.

The B310P provides a lower power level, the B320P provides approximately 1.5 kW, and the B330P increases torque further while remaining within the same general 100 mm frame class.

The B420P and B430P move into higher-capacity motor configurations with larger mechanical envelopes and higher torque capability.

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21. Detailed Parameters of the Five Representative Models

MPL-B310P-SJ72AA

The MPL-B310P-SJ72AA is a smaller 100 mm-frame MPL servo motor with a shorter magnetic stack than the B320P.

Parameter	Specification
Model	MPL-B310P-SJ72AA
Power	Approx. 0.77 kW
Continuous Torque	Approx. 1.58 N·m
Peak Torque	Approx. 3.61 N·m
Speed	5000 rpm
Frame	100 mm
Magnetic Stack	25.4 mm
Feedback	Single-turn high-resolution encoder
Shaft	Keyed
Brake	No brake
Rotor Inertia	Approx. 0.000044 kg·m²
Weight	Approx. 2.4 kg
Dimensions	B310P family envelope

The B310P can be considered when the required continuous torque is lower than that of the B320P.

MPL-B320P-SJ72AA

The MPL-B320P-SJ72AA is the subject model of this document.

Parameter	Specification
Model	MPL-B320P-SJ72AA
Power	Approx. 1.5 kW
Continuous Torque	Approx. 3.05 N·m
Peak Torque	Approx. 7.91 N·m
Speed	5000 rpm
Frame	100 mm
Magnetic Stack	50.8 mm
Feedback	Single-turn high-resolution encoder
Shaft	Keyed
Brake	No brake
Rotor Inertia	Approx. 0.000078 kg·m²
Weight	Approx. 4.5 kg
Dimensions	Approx. 42.8 × 21.7 × 26.0 cm family envelope

The B320P provides a substantial increase in torque and power compared with the B310P while maintaining the same general 100 mm frame class.

MPL-B330P-SJ72AA

The MPL-B330P-SJ72AA provides higher torque and uses a longer magnetic stack.

Parameter	Specification
Model	MPL-B330P-SJ72AA
Power	Approx. 1.8 kW
Continuous Torque	Approx. 4.18 N·m
Peak Torque	Approx. 11.1 N·m
Speed	5000 rpm
Frame	100 mm
Magnetic Stack	76.2 mm
Feedback	Single-turn high-resolution encoder
Shaft	Keyed
Brake	No brake
Rotor Inertia	Approx. 0.00012 kg·m²
Weight	Approx. 6.1 kg
Dimensions	B330P family envelope

This configuration provides additional torque capability for applications that exceed the continuous requirements of the B320P.

MPL-B420P-SJ72AA

The MPL-B420P-SJ72AA moves into a larger frame class and provides additional torque capability.

Parameter	Specification
Model	MPL-B420P-SJ72AA
Power	Approx. 1.9 kW
Continuous Torque	Approx. 4.74 N·m
Peak Torque	Approx. 13.5 N·m
Speed	5000 rpm
Frame	115 mm
Magnetic Stack	50.8 mm
Feedback	Single-turn high-resolution encoder
Shaft	Keyed
Brake	No brake
Rotor Inertia	Approx. 0.00026 kg·m²
Weight	Approx. 6.4 kg
Dimensions	B420P family envelope

The larger frame provides additional mechanical capacity while maintaining the 5000 rpm speed class.

MPL-B430P-SJ72AA

The MPL-B430P-SJ72AA represents a higher-output configuration in the same general motor family.

Parameter	Specification
Model	MPL-B430P-SJ72AA
Power	Approx. 2.2 kW
Continuous Torque	Approx. 6.55 N·m
Peak Torque	Approx. 19.8 N·m
Speed	5000 rpm
Frame	Larger MPL frame class
Feedback	Single-turn high-resolution encoder
Shaft	Keyed
Brake	No brake
Rotor Inertia	Approx. 0.00038 kg·m²
Weight	Approx. 9.2 kg
Dimensions	B430P family envelope

This type of motor is intended for machine axes requiring considerably more continuous and peak torque than the B320P.

22. MPL Motor Size Comparison

Model	Power	Continuous Torque	Peak Torque	Speed	Rotor Inertia	Weight	Dimensions
MPL-B310P-SJ72AA	0.77 kW	1.58 N·m	3.61 N·m	5000 rpm	0.000044 kg·m²	Approx. 2.4 kg	B310P envelope
MPL-B320P-SJ72AA	1.5 kW	3.05 N·m	7.91 N·m	5000 rpm	0.000078 kg·m²	Approx. 4.5 kg	B320P envelope
MPL-B330P-SJ72AA	1.8 kW	4.18 N·m	11.1 N·m	5000 rpm	0.00012 kg·m²	Approx. 6.1 kg	B330P envelope
MPL-B420P-SJ72AA	1.9 kW	4.74 N·m	13.5 N·m	5000 rpm	0.00026 kg·m²	Approx. 6.4 kg	B420P envelope
MPL-B430P-SJ72AA	2.2 kW	6.55 N·m	19.8 N·m	5000 rpm	0.00038 kg·m²	Approx. 9.2 kg	B430P envelope

This comparison makes the B320P position within the family easy to understand.

It provides a significant increase in torque over the B310P while remaining smaller than the larger B420P and B430P configurations.

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23. Advantages of the SJ72AA Configuration Compared With Other B320P Versions

Feature	MPL-B320P-SJ72AA	SJ74AA	SK72AA	SK74AA	MJ72AA
Single-Turn Encoder	Yes	Yes	Yes	Yes	No
Multi-Turn Encoder	No	No	No	No	Yes
Keyed Shaft	Yes	Yes	No	No	Yes
Keyless Shaft	No	No	Yes	Yes	No
Brake	No	24 V DC	No	24 V DC	No
Speed	5000 rpm	5000 rpm	5000 rpm	5000 rpm	5000 rpm
Power	Approx. 1.5 kW	Approx. 1.5 kW	Approx. 1.5 kW	Approx. 1.5 kW	Approx. 1.5 kW
Continuous Torque	Approx. 3.05 N·m	Approx. 3.05 N·m	Approx. 3.05 N·m	Approx. 3.05 N·m	Approx. 3.05 N·m
Weight	Approx. 4.5 kg	Approx. 4.5 kg class	Approx. 4.5 kg class	Approx. 4.5 kg class	Approx. 4.5–5.1 kg class
Dimensions	B320P envelope	B320P envelope	B320P envelope	B320P envelope	B320P envelope

The SJ72AA configuration is specifically characterized by the combination of single-turn high-resolution feedback, keyed shaft, and no brake.

This makes it important to distinguish it from models that look nearly identical but contain a brake or use a keyless shaft.

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24. Practical Selection Guide

For an application requiring approximately 1.5 kW and 3.05 N·m continuous torque, the B320P is within the appropriate performance range.

If the machine requires an integrated holding brake, the corresponding brake-equipped B320P configuration should be considered instead.

If the machine requires a keyless coupling arrangement, the SK configuration should be examined.

If the application requires multi-turn absolute feedback, an MJ or MK configuration may be more appropriate.

If the required torque is significantly higher than approximately 3.05 N·m continuous, the B330P, B420P, or B430P family should be evaluated according to the actual machine load.

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25. Overall Advantages Summary

Advantage	Explanation
High 5000 rpm speed	Suitable for rapid machine cycles
1.5 kW output	Useful for medium-duty servo axes
3.05 N·m continuous torque	Provides useful continuous mechanical output
7.91 N·m peak torque	Supports acceleration and transient loads
Low rotor inertia	Helps provide fast dynamic response
Single-turn encoder	Provides accurate closed-loop position feedback
Keyed shaft	Easy integration with keyed mechanical components
No brake	Simplifies applications that do not require mechanical holding
100 mm frame	Compact installation footprint
50.8 mm stack	Balanced torque and motor size
Right-angle connector	Helps with compact cable routing
180° connector rotation	Allows flexible connector orientation
IEC metric mounting	Convenient for metric machine construction
Free mounting holes	Provides installation flexibility

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26. Final Product Summary

The Allen-Bradley MPL-B320P-SJ72AA is a 5000 rpm, approximately 1.5 kW low-inertia brushless AC servo motor designed for precision industrial motion control.

Its principal specifications are a 100 mm frame, 50.8 mm magnetic stack, approximately 3.05 N·m continuous torque, approximately 7.91 N·m peak torque, single-turn high-resolution encoder, keyed shaft, SpeedTEC DIN right-angle connector, and no integrated brake.

The motor is particularly suitable for automated machinery requiring repeated acceleration and deceleration, accurate positioning, controlled speed, and reliable closed-loop feedback.

Typical applications include packaging equipment, automated assembly, material handling, printing, converting, labeling, indexing, inspection equipment, and electronics manufacturing.

The most important point when replacing or selecting this motor is to verify the complete catalog number, not simply the power rating.

The feedback system, shaft type, brake option, connector arrangement, frame size, mounting dimensions, and load requirements all need to match the machine.

For the MPL-B320P-SJ72AA, the defining combination is single-turn high-resolution encoder + keyed shaft + no brake + 5000 rpm + 1.5 kW + 3.05 N·m continuous torque + 100 mm frame + 50.8 mm magnetic stack.

That combination makes the model a compact, high-speed servo motor configuration for industrial machines where fast response and repeatable closed-loop motion are required.