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Allen-Bradley MPL-B320P-SJ74AA Servo Motor

1. Product Overview

The Allen-Bradley MPL-B320P-SJ74AA is a low-inertia brushless AC rotary servo motor designed for industrial motion-control systems that require accurate positioning, fast acceleration and deceleration, repeatable movement, and high-speed operation.

It belongs to the MP-Series MPL low-inertia servo motor family and is configured for the 460 V class. The motor uses a 100 mm frame, a 50.8 mm magnetic stack, and a 5000 rpm speed rating. It combines a single-turn high-resolution encoder with a keyed shaft, a right-angle rotatable SpeedTEC DIN connector, and an integrated 24 V DC holding brake.

The B320P size provides approximately 1.5 kW continuous power, 3.05 N·m continuous torque, and approximately 7.91 N·m peak torque. This makes it suitable for many automated machine axes where the motor needs to accelerate rapidly and repeatedly follow precise motion commands.

The SJ74AA configuration is especially useful when the machine requires a keyed shaft and an integral 24 V DC brake. The brake-equipped design makes it different from the closely related SJ72AA version, which does not have the integral brake.

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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 rotary servo motor
Model	MPL-B320P-SJ74AA
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 extension
Brake	24 V DC holding brake
Connector	SpeedTEC DIN
Connector Style	Right-angle
Connector Rotation	180° rotatable
Mounting	IEC metric flange
Mounting Holes	Free mounting holes, Type FF
Motor Design	Low-inertia permanent-magnet servo motor
Weight	Approx. 4.54 kg
Dimensions	Approx. 42.8 × 21.7 × 26.0 cm, B320P-family installation envelope

The product description identifies the motor as an MPL low-inertia brushless servo motor with a 100 mm frame, 50.8 mm stack, 5000 rpm rating, single-turn high-resolution encoder, keyed shaft, SpeedTEC DIN connector, and 24 V DC brake.

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3. Model Number Explanation

The complete model number MPL-B320P-SJ74AA contains information about the motor’s voltage class, frame size, magnetic stack, speed, feedback system, shaft configuration, connector arrangement, and brake.

Model Code	General Meaning
MPL	MPL low-inertia servo motor family
B	460 V-class motor family
3	100 mm frame class
20	50.8 mm / 2.0 in magnetic stack
P	5000 rpm speed class
S	Single-turn high-resolution encoder
J	Keyed shaft extension
7	SpeedTEC DIN right-angle connector, 180° rotatable
4	24 V DC brake
AA	Standard catalog configuration

This coding system is particularly useful when selecting replacement motors.

Several motors within the B320P family can have almost identical mechanical dimensions while using different feedback devices, shaft configurations, or brake options.

For example, SJ72AA and SJ74AA are closely related configurations, but the SJ74AA includes the 24 V DC brake.

Likewise, an SK configuration uses a keyless shaft, while an MJ configuration uses a different feedback arrangement.

For replacement work, the complete catalog number should therefore be matched rather than selecting a motor simply because the frame size and power rating appear similar.

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4. Main Technical Specifications

Parameter	Specification
Model	MPL-B320P-SJ74AA
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	Absolute single-turn high-resolution encoder
Feedback Resolution	Sin/Cos, 1024 cycles/rev
Feedback Protocol	Hiperface protocol
Shaft	Keyed shaft extension
Shaft Seal	No shaft seal
Brake	24 V DC holding brake
Connector	SpeedTEC DIN
Connector Position	Right-angle
Connector Rotation	180° rotatable
Mounting Flange	IEC metric
Mounting Hole Style	Free mounting holes, Type FF
Rotor Inertia	Approx. 9.2 × 10⁻⁵ kg·m²
Maximum Operating Temperature	Approx. 40 °C under standard conditions
Weight	Approx. 4.54 kg
Dimensions	Approx. 42.8 × 21.7 × 26.0 cm, B320P-family envelope

The published technical data identifies the motor as a 5000 rpm servo motor with 3.05 N·m continuous torque, 7.91 N·m peak torque, 1.5 kW continuous power, 50.8 mm magnetic stack, 100 mm frame, single-turn absolute encoder, keyed shaft, and 24 V DC brake.

The exact product weight is approximately 4.54 kg in current product listings.

The dimensions shown above should be regarded as an approximate B320P-family envelope rather than a replacement for the exact mechanical drawing. The actual installation should always be checked against the motor drawing, particularly where there is limited clearance around the connector, shaft, or flange.

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5. Electrical Performance

Parameter	Value
Model	MPL-B320P-SJ74AA
Voltage Class	460 V AC
Continuous 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
Rotor Inertia	Approx. 0.000092 kg·m²
Brake Voltage	24 V DC
Feedback	Absolute single-turn encoder
Feedback Resolution	1024 Sin/Cos cycles/rev
Frame Size	100 mm
Magnetic Stack	50.8 mm
Weight	Approx. 4.54 kg
Dimensions	Approx. 42.8 × 21.7 × 26.0 cm family envelope

The combination of 1.5 kW power, 3.05 N·m continuous torque, and 5000 rpm speed gives the motor a useful operating range for medium-duty automated machine axes.

The peak torque rating is important during acceleration and deceleration. A machine may require considerably more torque for a short period during an indexing cycle than it needs during steady-state operation.

The actual motor selection should therefore consider the complete torque-time profile rather than only the continuous load.

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6. Torque Characteristics

The continuous torque rating of approximately 3.05 N·m represents the motor’s continuous mechanical output capability under the specified operating conditions.

The peak torque of approximately 7.91 N·m provides additional short-duration torque for acceleration, deceleration, and transient load conditions.

Torque Parameter	Specification
Model	MPL-B320P-SJ74AA
Continuous Torque	Approx. 3.05 N·m
Peak Torque	Approx. 7.91 N·m
Continuous-to-Peak Ratio	Approx. 2.6 : 1
Rated Speed	5000 rpm
Power Class	Approx. 1.5 kW
Rotor Inertia	Approx. 0.000092 kg·m²
Weight	Approx. 4.54 kg
Dimensions	Approx. 42.8 × 21.7 × 26.0 cm family envelope

The relatively large difference between continuous and peak torque allows the servo system to handle short acceleration events without requiring the continuous motor rating to be sized solely around the highest instantaneous torque.

However, peak torque is not intended to be treated as a continuous operating point. The actual duty cycle, acceleration time, load inertia, speed, and thermal conditions must all be considered.

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7. Feedback System

The MPL-B320P-SJ74AA uses an absolute single-turn high-resolution encoder.

The encoder provides the servo drive with detailed information about the motor shaft position and speed.

The published configuration specifies Sin/Cos feedback with 1024 cycles per revolution and Hiperface protocol.

This feedback arrangement is important for closed-loop motion control.

The servo drive compares the commanded position or speed with the actual feedback position and continuously adjusts motor current to reduce the difference between the commanded and actual motion.

This makes the motor suitable for applications involving:

• Accurate indexing
• Position control
• Electronic gearing
• Coordinated motion
• Speed synchronization
• Repeated acceleration and deceleration
• Registration control
• High-cycle machine operation

The single-turn configuration is designed to provide absolute position information within one revolution.

For applications that require absolute position information across multiple revolutions, a multi-turn motor configuration should be considered instead.

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8. Keyed Shaft Configuration

The MPL-B320P-SJ74AA uses a keyed shaft extension.

A keyed shaft is useful when the motor is connected to a traditional keyed coupling, pulley, gear, or mechanical transmission.

Mechanical Feature	Specification
Model	MPL-B320P-SJ74AA
Shaft Type	Keyed
Shaft Extension	Standard keyed shaft
Shaft Seal	No shaft seal
Mounting	IEC metric flange
Frame	100 mm
Magnetic Stack	50.8 mm
Brake	24 V DC
Weight	Approx. 4.54 kg
Dimensions	Approx. 42.8 × 21.7 × 26.0 cm family envelope

Correct shaft alignment is important.

Angular misalignment, parallel misalignment, excessive radial force, or excessive axial loading can increase bearing stress and create vibration.

The coupling should therefore be installed according to the mechanical requirements of the motor and driven machine.

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9. Integrated 24 V DC Brake

One of the most important features of the SJ74AA configuration is the integrated 24 V DC holding brake.

The brake is intended primarily to hold the motor shaft when the servo system is not actively producing torque.

This can be particularly useful for:

• Vertical axes
• Lift mechanisms
• Indexing equipment
• Position-holding applications
• Machines where shaft movement must be restricted while stopped
• Equipment where the motor needs mechanical holding after servo disable

The brake should not automatically be treated as the normal dynamic stopping device.

In many machine designs, the servo drive performs the controlled deceleration while the mechanical brake is used for holding once the motor has reached the required stopped condition.

The brake control sequence should be designed carefully so that the brake is released and applied at the correct time.

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10. Connector Configuration

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

The connector is designed to be rotated through approximately 180 degrees, giving the installer additional freedom when routing cables.

This arrangement is useful in compact machinery because the connector does not have to point in only one fixed direction.

It can help avoid interference with:

• Machine guards
• Structural members
• Cable trays
• Adjacent motors
• Gearboxes
• Pneumatic equipment
• Sensors
• Other electrical components

Proper connector engagement is important for both the power circuit and feedback circuit.

An improperly seated connector can cause intermittent motor operation, encoder faults, feedback loss, drive trips, or unexpected machine stops.

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11. Mounting Configuration

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

The 100 mm frame size and 50.8 mm magnetic stack are important mechanical identifiers for the B320P configuration.

Mounting Parameter	Specification
Model	MPL-B320P-SJ74AA
Mounting Type	Flange mount
Flange Standard	IEC metric
Frame Size	100 mm
Magnetic Stack	50.8 mm
Mounting Holes	Free mounting holes, Type FF
Shaft	Keyed
Brake	24 V DC
Connector	SpeedTEC DIN
Connector Style	Right angle
Connector Rotation	180°
Weight	Approx. 4.54 kg
Dimensions	Approx. 42.8 × 21.7 × 26.0 cm family envelope

The machine mounting structure should provide adequate clearance for the motor body, shaft coupling, connector, cables, and brake wiring.

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12. Product Introduction

The MPL-B320P-SJ74AA is designed as a complete motion-control motor rather than simply a general-purpose rotating motor.

The motor is intended to work together with a compatible servo drive and motion controller.

During operation, the drive supplies controlled electrical current to the motor while the encoder provides feedback about the actual shaft position and movement.

This closed-loop process allows the machine to perform controlled motion with significantly greater precision than a conventional open-loop motor arrangement.

The low-inertia design is especially useful in applications where the motor must repeatedly accelerate and decelerate.

For example, an indexing machine may need to move from one position to another, stop precisely, remain stationary, and then repeat the same movement many times.

The B320P motor is well suited to this type of duty when its torque, speed, inertia, and thermal requirements are properly matched to the application.

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13. Low-Inertia Design

Low rotor inertia is one of the defining characteristics of the MPL motor family.

The B320P configuration has a rotor inertia of approximately 9.2 × 10⁻⁵ kg·m².

Lower rotor inertia can help the motor change speed quickly because less rotational energy is stored in the rotor itself.

This can be useful for:

• High-speed indexing
• Frequent starts and stops
• Rapid acceleration
• Rapid deceleration
• Reversing applications
• Short-cycle automation
• Positioning systems
• Electronic synchronization

The actual response of the machine still depends on the load inertia and mechanical transmission.

A low-inertia motor does not automatically guarantee optimum servo performance if the driven load is very large or poorly matched.

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14. Main Product Advantages

14.1 5000 rpm High-Speed Capability

The 5000 rpm speed rating makes the motor suitable for high-cycle industrial machinery.

High motor speed can reduce the time required for rotary movements and can also provide additional flexibility when a gearbox, belt drive, or other transmission is used.

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14.2 1.5 kW Continuous Power

The approximately 1.5 kW continuous power rating provides a useful output level for medium-duty industrial servo axes.

It offers a balance between compact motor size and mechanical output.

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14.3 3.05 N·m Continuous Torque

The approximately 3.05 N·m continuous torque rating allows the motor to handle a meaningful continuous mechanical load.

This is especially important in machines where the motor must continuously overcome friction, gravity, cutting forces, or transmission losses.

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14.4 7.91 N·m Peak Torque

The peak torque capability provides additional short-term output during acceleration and transient load conditions.

This can be useful for high-speed indexing and rapid changes in machine motion.

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14.5 Low Rotor Inertia

The low-inertia rotor design helps the motor respond quickly to motion commands.

This is one of the main reasons the MPL family is suitable for dynamic motion applications.

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14.6 High-Resolution Single-Turn Feedback

The high-resolution encoder provides accurate position information to the servo drive.

This supports repeatable positioning and controlled speed operation.

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14.7 Integrated 24 V DC Brake

The integrated brake provides mechanical shaft holding when required.

This is particularly useful for vertical or gravity-loaded applications where the axis needs to remain stationary when servo torque is removed.

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14.8 Keyed Shaft

The keyed shaft provides a familiar mechanical interface for standard couplings and machine transmissions.

This can simplify integration into existing machinery.

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14.9 Flexible Connector Orientation

The 180° rotatable right-angle connector provides additional flexibility during installation.

This can be valuable when motor mounting space is limited.

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14.10 Compact 100 mm Frame

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

This makes the motor suitable for machinery where available space is limited.

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15. Typical Applications

Packaging Machinery

The MPL-B320P-SJ74AA can be used for packaging-machine axes requiring accurate indexing and repeated acceleration and deceleration.

Typical functions include:

• Product feeding
• Product indexing
• Sealing mechanisms
• Cutting mechanisms
• Film positioning
• Rotary indexing
• Product transfer

The encoder allows the machine controller to monitor actual shaft movement, while the brake can provide holding capability where required.

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16. Automated Assembly Equipment

Automated assembly machines often use servo motors for controlled positioning.

The B320P can be considered for:

• Transfer mechanisms
• Rotary indexing tables
• Assembly stations
• Positioning slides
• Pick-and-place mechanisms
• Component insertion systems
• Fixture positioning

The low-inertia design is useful when the machine performs frequent short movements.

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17. Material Handling Systems

Servo motors can be used in material-handling machinery when precise positioning is required.

Possible applications include:

• Indexing conveyors
• Transfer systems
• Positioning mechanisms
• Rotary tables
• Lift mechanisms
• Automated handling systems

The integral brake is particularly relevant to applications where the load must remain mechanically held when the motor is disabled.

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18. Printing Machinery

Printing equipment often requires coordinated rotary motion.

The B320P can be applied to:

• Registration mechanisms
• Feed rollers
• Positioning systems
• Indexing mechanisms
• Controlled rotary axes
• Synchronization systems

The encoder feedback supports accurate synchronization between the servo axis and other machine components.

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19. Converting Equipment

Converting machinery often requires precise control of cutting, feeding, and indexing.

Potential applications include:

• Web handling
• Cutting
• Feeding
• Indexing
• Rotary positioning
• Synchronization

The 5000 rpm capability can be useful in high-cycle production environments.

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20. Labeling Equipment

Labeling machines require accurate synchronization between product movement and labeling mechanisms.

The motor can be used for controlled product feeding, label application mechanisms, indexing, and other servo-controlled movements.

The high-resolution encoder provides the position information necessary for repeatable machine cycles.

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21. Electronics Manufacturing

Electronics manufacturing systems often require precise positioning of relatively small loads.

The B320P can be considered for:

• Component handling
• Automated transfer
• Inspection stations
• Feeder systems
• Positioning mechanisms
• Indexing tables

The low-inertia motor design is useful when the machine requires rapid movement with frequent changes in direction.

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22. Inspection and Test Equipment

Inspection equipment can use servo motors to position fixtures, sensors, cameras, or test components.

Typical applications include:

• Rotary inspection tables
• Camera positioning
• Sensor positioning
• Test fixtures
• Component orientation
• Automated measurement systems

The encoder feedback allows the controller to verify and control motor position.

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23. Application Summary

Application	Typical Servo Function	Relevant Feature
Packaging	Indexing and positioning	5000 rpm + encoder
Assembly	Transfer and positioning	Low inertia
Material Handling	Indexing and lifting	24 V DC brake
Printing	Registration and synchronization	High-resolution feedback
Converting	Feeding and cutting	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
Vertical Axis	Position holding	Integral brake

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24. Installation Considerations

The MPL-B320P-SJ74AA should be selected based on the complete mechanical and electrical requirements of the machine.

The first consideration is continuous torque.

The motor should have sufficient continuous torque for the actual operating load, including friction, gravity, transmission losses, and other mechanical forces.

The second consideration is peak torque.

Acceleration and deceleration can require significantly more torque than steady-state operation.

The third consideration is load inertia.

The reflected inertia of the driven mechanism should be considered when evaluating servo response.

The fourth consideration is feedback compatibility.

The drive must be compatible with the single-turn high-resolution encoder used by this motor.

The fifth consideration is the brake.

If the machine relies on the motor brake to hold a vertical or gravity-loaded axis, the brake-control sequence should be carefully designed.

The sixth consideration is the mechanical shaft.

The keyed shaft must be compatible with the selected coupling or transmission component.

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25. Brake Application Considerations

The 24 V DC brake is a useful feature, but it should be applied correctly.

The brake is primarily intended for holding rather than routine dynamic stopping.

A typical machine sequence may involve:

1. Servo drive commands the motor to decelerate.
2. Motor reaches the required stopped condition.
3. Servo torque is controlled according to the machine sequence.
4. Brake is applied.
5. Servo torque is removed when appropriate.

The exact sequence depends on the machine architecture and safety requirements.

The brake should not be used as a substitute for a properly engineered safety system.

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26. Maintenance Considerations

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

Maintenance Item	What to Check
Model	MPL-B320P-SJ74AA
Motor Temperature	Excessive heating
Vibration	Unusual vibration or resonance
Bearing Condition	Noise or mechanical roughness
Shaft	Wear, damage, or abnormal movement
Coupling	Alignment and mechanical condition
Encoder Cable	Damage, bending, or loose connection
Power Cable	Insulation and connector condition
Brake	Correct release and holding action
Connector	Proper engagement and locking
Mounting	Loose mounting hardware
Servo Feedback	Position or encoder errors
Weight	Approx. 4.54 kg
Dimensions	Approx. 42.8 × 21.7 × 26.0 cm family envelope

If encoder faults occur repeatedly, the feedback cable and connector should be inspected before assuming that the encoder itself has failed.

If abnormal vibration is present, the coupling, driven load, bearings, and mounting structure should also be checked.

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27. Five Closely Related Models

The following five models are closely related to the MPL-B320P-SJ74AA and are useful when comparing different feedback, shaft, and brake configurations.

Model	Feedback	Shaft	Brake	Speed	Power	Continuous Torque	Frame	Stack	Weight	Dimensions
MPL-B320P-SJ72AA	Single-turn high-resolution encoder	Keyed	No	5000 rpm	Approx. 1.5 kW	Approx. 3.05 N·m	100 mm	50.8 mm	Approx. 4.54 kg	Approx. 42.8 × 21.7 × 26.0 cm family envelope
MPL-B320P-SK72AA	Single-turn high-resolution encoder	Keyless	No	5000 rpm	Approx. 1.5 kW	Approx. 3.05 N·m	100 mm	50.8 mm	Approx. 4.5 kg class	Approx. B320P 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. B320P family envelope
MPL-B320P-MJ72AA	Multi-turn high-resolution encoder	Keyed	No	5000 rpm	Approx. 1.5 kW	Approx. 3.05 N·m	100 mm	50.8 mm	Approx. 4.5–5.1 kg class	Approx. B320P 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. B320P family envelope

The most direct comparison is the MPL-B320P-SJ72AA.

The two models share the same basic B320P motor class and feedback/shaft configuration, but the SJ74AA adds the 24 V DC brake.

The SK configurations change the shaft from keyed to keyless.

The MJ configurations change the feedback arrangement to multi-turn high-resolution feedback.

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28. Related Model Comparison

Feature	MPL-B320P-SJ74AA	MPL-B320P-SJ72AA	MPL-B320P-SK72AA	MPL-B320P-SK74AA	MPL-B320P-MJ74AA
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	Single-turn	Single-turn	Single-turn	Multi-turn
Shaft	Keyed	Keyed	Keyless	Keyless	Keyed
Brake	24 V DC	None	None	24 V DC	24 V DC
Connector	SpeedTEC DIN	SpeedTEC DIN	SpeedTEC DIN	SpeedTEC DIN	SpeedTEC DIN
Weight	Approx. 4.54 kg	Approx. 4.54 kg	Approx. 4.5 kg class	Approx. 4.5 kg class	Approx. 4.5–5.1 kg class
Dimensions	B320P family envelope	B320P family envelope	B320P family envelope	B320P family envelope	B320P family envelope

This comparison shows that the motor capacity can remain almost identical while the functional configuration changes.

The most important differences for system integration are feedback type, shaft configuration, and brake availability.

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29. Five Representative Same-Brand Models

The following five models are representative same-brand servo motors that can be used for comparison across different output levels and configurations.

They are presented as representative models rather than a formal popularity ranking.

Model	Power	Continuous Torque	Peak Torque	Speed	Frame	Stack	Feedback	Shaft	Brake	Weight	Dimensions
MPL-B310P-SJ74AA	Approx. 0.77 kW	Approx. 1.58 N·m	Approx. 3.61 N·m	5000 rpm	100 mm	25.4 mm	Single-turn encoder	Keyed	24 V DC	Approx. 2.4–3 kg class	B310P family envelope
MPL-B320P-SJ74AA	Approx. 1.5 kW	Approx. 3.05 N·m	Approx. 7.91 N·m	5000 rpm	100 mm	50.8 mm	Single-turn encoder	Keyed	24 V DC	Approx. 4.54 kg	B320P family envelope
MPL-B330P-SJ74AA	Approx. 1.8 kW	Approx. 4.18 N·m	Approx. 11.1 N·m	5000 rpm	100 mm	76.2 mm	Single-turn encoder	Keyed	24 V DC	Approx. 6.1 kg	B330P family envelope
MPL-B420P-SJ74AA	Approx. 1.9 kW	Approx. 4.74 N·m	Approx. 13.5 N·m	5000 rpm	Larger frame class	50.8 mm class	Single-turn encoder	Keyed	24 V DC	Approx. 6.4 kg	B420P family envelope
MPL-B430P-SJ74AA	Approx. 2.2 kW	Approx. 6.55 N·m	Approx. 19.8 N·m	5000 rpm	Larger frame class	Longer stack	Single-turn encoder	Keyed	24 V DC	Approx. 9.2 kg	B430P family envelope

These models show the progression from lower-output to higher-output MPL servo motors.

The B310P is a smaller motor, the B320P occupies the approximately 1.5 kW class, and the B330P provides additional torque while remaining within the same general 100 mm frame family.

The B420P and B430P provide higher torque capability and use larger mechanical configurations.

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30. Detailed Parameters of Representative Same-Brand Models

MPL-B310P-SJ74AA

The MPL-B310P-SJ74AA is a smaller motor in the MPL family and can be considered when the machine requires less continuous torque than the B320P.

Parameter	Specification
Model	MPL-B310P-SJ74AA
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	Approx. 25.4 mm
Feedback	Single-turn high-resolution encoder
Shaft	Keyed
Brake	24 V DC
Rotor Inertia	Approx. 0.000044 kg·m²
Weight	Approx. 2.4–3 kg class
Dimensions	B310P family envelope

Its lower torque and shorter stack make it useful for smaller servo axes where the B320P output level would be unnecessary.

MPL-B320P-SJ74AA

The MPL-B320P-SJ74AA is the primary model discussed in this document.

Parameter	Specification
Model	MPL-B320P-SJ74AA
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	24 V DC
Rotor Inertia	Approx. 0.000092 kg·m²
Weight	Approx. 4.54 kg
Dimensions	Approx. 42.8 × 21.7 × 26.0 cm family envelope

This configuration combines a keyed shaft and single-turn encoder with the integrated 24 V DC brake.

MPL-B330P-SJ74AA

The MPL-B330P-SJ74AA provides a higher torque level than the B320P.

Parameter	Specification
Model	MPL-B330P-SJ74AA
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	Approx. 76.2 mm
Feedback	Single-turn high-resolution encoder
Shaft	Keyed
Brake	24 V DC
Rotor Inertia	Approx. 0.00012 kg·m²
Weight	Approx. 6.1 kg
Dimensions	B330P family envelope

This motor can be considered where the required continuous torque exceeds the practical range of the B320P.

MPL-B420P-SJ74AA

The MPL-B420P-SJ74AA provides another increase in continuous and peak torque.

Parameter	Specification
Model	MPL-B420P-SJ74AA
Power	Approx. 1.9 kW
Continuous Torque	Approx. 4.74 N·m
Peak Torque	Approx. 13.5 N·m
Speed	5000 rpm
Frame	Larger MPL frame class
Magnetic Stack	Approx. 50.8 mm class
Feedback	Single-turn high-resolution encoder
Shaft	Keyed
Brake	24 V DC
Rotor Inertia	Approx. 0.00026 kg·m²
Weight	Approx. 6.4 kg
Dimensions	B420P family envelope

This configuration is suited to higher-load servo axes where additional torque is required.

MPL-B430P-SJ74AA

The MPL-B430P-SJ74AA is a higher-output configuration within the same general MPL family.

Parameter	Specification
Model	MPL-B430P-SJ74AA
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	24 V DC
Rotor Inertia	Approx. 0.00038 kg·m²
Weight	Approx. 9.2 kg
Dimensions	B430P family envelope

This model provides substantially greater torque capability for heavier machine axes.

31. MPL Family Performance Comparison

Model	Power	Continuous Torque	Peak Torque	Speed	Rotor Inertia	Weight	Dimensions
MPL-B310P-SJ74AA	0.77 kW	1.58 N·m	3.61 N·m	5000 rpm	0.000044 kg·m²	Approx. 2.4–3 kg	B310P envelope
MPL-B320P-SJ74AA	1.5 kW	3.05 N·m	7.91 N·m	5000 rpm	0.000092 kg·m²	Approx. 4.54 kg	B320P envelope
MPL-B330P-SJ74AA	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-SJ74AA	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-SJ74AA	2.2 kW	6.55 N·m	19.8 N·m	5000 rpm	0.00038 kg·m²	Approx. 9.2 kg	B430P envelope

The B320P occupies an intermediate position in this group.

It provides substantially more continuous torque than the B310P while remaining smaller than the larger B420P and B430P configurations.

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32. SJ74AA Compared With SJ72AA

The MPL-B320P-SJ72AA and MPL-B320P-SJ74AA are particularly close in specification.

Parameter	MPL-B320P-SJ74AA	MPL-B320P-SJ72AA
Voltage Class	460 V AC	460 V AC
Power	Approx. 1.5 kW	Approx. 1.5 kW
Continuous Torque	Approx. 3.05 N·m	Approx. 3.05 N·m
Peak Torque	Approx. 7.91 N·m	Approx. 7.91 N·m
Speed	5000 rpm	5000 rpm
Frame	100 mm	100 mm
Magnetic Stack	50.8 mm	50.8 mm
Feedback	Single-turn encoder	Single-turn encoder
Shaft	Keyed	Keyed
Brake	24 V DC	No brake
Connector	SpeedTEC DIN	SpeedTEC DIN
Connector Rotation	180°	180°
Mounting	IEC metric	IEC metric
Weight	Approx. 4.54 kg	Approx. 4.54 kg
Dimensions	Approx. B320P family envelope	Approx. B320P family envelope

The principal difference is the brake.

The SJ74AA includes the 24 V DC holding brake, while the SJ72AA does not.

For machines with a vertical axis or another load that must remain mechanically held after servo torque is removed, the brake configuration becomes an important part of the motor selection.

33. Practical Application Selection

The MPL-B320P-SJ74AA can be considered when the application has the following characteristics:

• Approximately 1.5 kW continuous motor power requirement
• Approximately 3.05 N·m continuous torque requirement
• Up to 5000 rpm operation
• Frequent acceleration and deceleration
• Accurate closed-loop positioning
• Single-turn absolute feedback requirement
• Keyed mechanical coupling
• Need for an integrated 24 V DC holding brake
• 100 mm frame installation
• IEC metric flange mounting

The motor should be evaluated against the actual machine load rather than selected solely because the motor’s nominal power appears suitable.

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34. Engineering Checklist

Selection Item	MPL-B320P-SJ74AA Consideration
Model	MPL-B320P-SJ74AA
Voltage	460 V-class system
Continuous Power	Approx. 1.5 kW
Continuous Torque	Approx. 3.05 N·m
Peak Torque	Approx. 7.91 N·m
Speed	5000 rpm
Feedback	Single-turn high-resolution encoder
Shaft	Keyed
Brake	24 V DC
Frame	100 mm
Stack	50.8 mm
Mounting	IEC metric flange
Connector	SpeedTEC DIN right-angle
Connector Adjustment	180° rotatable
Weight	Approx. 4.54 kg
Dimensions	Approx. 42.8 × 21.7 × 26.0 cm family envelope
Main Design Check	Load torque and inertia
Additional Check	Drive and feedback compatibility
Mechanical Check	Shaft and flange dimensions
Brake Check	Holding and control requirements

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35. Overall Product Advantages

Advantage	Description
5000 rpm operation	Suitable for fast machine cycles
1.5 kW output	Useful for medium-duty servo axes
3.05 N·m continuous torque	Provides substantial continuous mechanical output
7.91 N·m peak torque	Supports short-duration acceleration loads
Low-inertia rotor	Helps achieve fast dynamic response
Single-turn encoder	Provides high-resolution position feedback
Keyed shaft	Convenient for traditional mechanical couplings
24 V DC brake	Provides shaft holding capability
100 mm frame	Compact installation format
50.8 mm magnetic stack	Balanced motor size and torque
SpeedTEC DIN connector	Industrial servo connection
180° rotatable connector	Flexible cable routing
IEC metric flange	Suitable for metric machine mounting
Free mounting holes	Provides mounting flexibility

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36. Final Product Summary

The Allen-Bradley MPL-B320P-SJ74AA is a low-inertia, 5000 rpm brushless AC rotary servo motor designed for industrial motion-control applications.

Its principal configuration is 460 V class, 1.5 kW continuous power, 3.05 N·m continuous torque, 7.91 N·m peak torque, 100 mm frame, 50.8 mm magnetic stack, single-turn high-resolution encoder, keyed shaft, SpeedTEC DIN right-angle connector, and integrated 24 V DC holding brake.

The approximately 4.54 kg product weight makes it a relatively compact motor for its performance class.

The motor is particularly suitable for automated machinery that requires fast, repeatable, closed-loop rotary motion.

Typical applications include packaging equipment, automated assembly, material handling, printing, converting, labeling, inspection equipment, indexing systems, electronics manufacturing equipment, and selected vertical-axis applications.

The integrated brake is one of the most important differences between this model and the closely related SJ72AA version.

The SJ74AA combines a keyed shaft, single-turn high-resolution feedback, and a 24 V DC holding brake, making the complete model configuration important when selecting a replacement motor.

For replacement or new-machine design, the complete catalog number should be checked against the required electrical, feedback, mechanical, and brake specifications.

The main characteristics to verify are voltage, continuous torque, peak torque, speed, encoder type, shaft configuration, brake requirement, frame size, mounting pattern, connector arrangement, load inertia, and actual machine duty cycle.

The MPL-B320P-SJ74AA is therefore best understood as a complete servo-motor configuration rather than simply a 1.5 kW motor. Its feedback, low-inertia construction, keyed shaft, flexible connector, and integrated brake all contribute to how it can be incorporated into an industrial motion-control system.