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MPL-B420P-MK74AA Low-Inertia Servo Motor

1. Product Overview

The MPL-B420P-MK74AA is a high-speed, low-inertia brushless AC servo motor designed for precision motion control, automated machinery, industrial production equipment and high-speed positioning applications.

It belongs to the MP-Series MPL Low-Inertia Servo Motor family and is designed for a 460 V AC class power system. The motor uses a 115 mm frame size, a 50.8 mm magnet stack, and a rated speed of approximately 5000 RPM.

One of the important characteristics of this model is its multi-turn high-resolution absolute encoder. The feedback system provides detailed position information for closed-loop servo control and is particularly suitable for machines requiring repeatable positioning, synchronized movement and controlled acceleration and deceleration.

The model uses a keyless shaft extension and a right-angle SpeedTEC DIN connector that can be rotated through approximately 180 degrees. Unlike the no-brake version, the MPL-B420P-MK74AA is equipped with a 24 V DC holding brake, making it more suitable for applications where the motor shaft or machine axis needs to be held when the servo system is not actively driving the motor.

With a compact 115 mm frame, low-inertia rotor construction, high rotational speed, absolute feedback and integral 24 V DC brake, the MPL-B420P-MK74AA is a practical choice for demanding industrial motion applications.

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2. Brand and Product Series

Item	Description
Brand	Allen-Bradley
Product Family	MP-Series
Product Series	MPL Low-Inertia Servo Motors
Product Category	Rotary Servo Motor
Motor Type	Brushless AC Servo Motor
Model	MPL-B420P-MK74AA
Voltage Class	460 V AC
Frame Size	115 mm
Magnet Stack	50.8 mm
Rated Speed	5000 RPM
Feedback	Multi-turn high-resolution absolute encoder
Shaft Configuration	Keyless shaft extension
Brake	24 V DC integral brake
Connector	SpeedTEC DIN
Connector Type	Right-angle
Connector Adjustment	180° rotatable
Mounting	IEC metric
Mounting Hole Type	Free mounting holes / Type FF
Servo Motor Classification	Low-inertia
Typical Use	Precision industrial motion control

The MPL-B420P-MK74AA can therefore be classified as a 115 mm-frame, 460 V-class, 5000 RPM, low-inertia rotary servo motor with multi-turn absolute feedback and a 24 V DC brake.

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3. Detailed Technical Specifications

Parameter	Specification
Model	MPL-B420P-MK74AA
Brand	Allen-Bradley
Product Series	MP-Series MPL
Series Description	Low-Inertia Brushless Servo Motor
Motor Type	Brushless Permanent-Magnet AC Servo Motor
Rated Voltage	460 V AC
Voltage Class	400/460 V AC class
Rated Speed	5000 RPM
Maximum Speed	5000 RPM
Rated Power	Approximately 1.9 kW
Continuous Stall Torque	Approximately 4.74 N·m
Peak Stall Torque	Approximately 13.5 N·m
Frame Size	115 mm
Frame Size	4.53 in
Magnet Stack Length	50.8 mm
Magnet Stack Length	2.0 in
Feedback	Multi-turn high-resolution absolute encoder
Feedback Type	Absolute multi-turn
Feedback Resolution	High-resolution Sin/Cos type feedback configuration
Feedback Protocol	Hiperface-type configuration
Shaft	Keyless shaft extension
Shaft Key	No
Brake	Yes
Brake Voltage	24 V DC
Brake Type	Integral holding brake
Connector	SpeedTEC DIN
Connector Position	Right-angle
Connector Rotation	Approximately 180°
Mounting Standard	IEC metric
Mounting Type	Flange mount
Mounting Holes	Free mounting holes / Type FF
Shaft Seal	No standard shaft seal
Standard Enclosure	IP50 class
Higher Environmental Protection	IP66 class configuration possible with suitable sealing arrangement
Rotor Inertia	Approximately 0.00026–0.00030 kg·m²
Approx. Overall Dimensions	Approximately 133 × 187 × 98 mm
Approx. Dimensions	Approximately 5.23 × 7.36 × 3.86 in
Approx. Weight	Approximately 5.5 kg
Approx. Weight in Pounds	Approximately 12.1 lb
Operating Temperature	Approximately 0 to 40 °C
Mounting Orientation	Suitable for industrial machine mounting
Application	Servo-controlled industrial machinery
Control System	Closed-loop motion control
Motor Construction	Compact low-inertia construction
Brake Function	Holding function when properly energized/de-energized according to system design

The dimensions should be regarded as an approximate overall envelope rather than a substitute for a detailed mechanical drawing. Connector orientation, shaft configuration and installation arrangement can affect the actual space required around the motor.

The 5.5 kg figure should likewise be treated as an approximate product weight. Actual measured weight can vary slightly with production revision and measurement method.

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4. Main Specifications at a Glance

Specification	MPL-B420P-MK74AA
Model	MPL-B420P-MK74AA
Voltage	460 V AC
Rated Speed	5000 RPM
Rated Power	Approx. 1.9 kW
Continuous Torque	4.74 N·m
Peak Torque	13.5 N·m
Frame Size	115 mm
Stack Length	50.8 mm
Feedback	Multi-turn absolute
Shaft	Keyless
Brake	24 V DC
Connector	Right-angle SpeedTEC DIN
Connector Rotation	180°
Protection	IP50 standard
Approx. Dimensions	133 × 187 × 98 mm
Approx. Weight	5.5 kg
Mounting	IEC metric flange
Motor Category	Low-inertia servo
Typical Speed Application	High-speed positioning
Typical Machine Type	Automated industrial equipment

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5. Product Model Number Interpretation

The catalog number MPL-B420P-MK74AA identifies the motor family and several major configuration characteristics.

Code	General Meaning
MPL	MPL low-inertia servo motor family
B	460 V-class motor configuration
4	115 mm frame-size class
20	50.8 mm magnet-stack class
P	5000 RPM configuration
M	Multi-turn high-resolution absolute feedback
K	Keyless shaft
7	SpeedTEC DIN right-angle connector configuration
4	24 V DC brake configuration
AA	Catalog/configuration designation

The most important difference between the MK74AA and a closely related MK72AA configuration is the brake arrangement.

The MK74AA includes a 24 V DC brake, while the corresponding MK72AA configuration is generally identified as the no-brake version.

This distinction is important when selecting a replacement because a motor with an integral brake requires the correct brake wiring, control arrangement and mechanical clearance.

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6. Product Introduction

The MPL-B420P-MK74AA is designed for machine axes that require a combination of high speed, accurate positioning and rapid dynamic response.

Servo motors are different from ordinary industrial motors because they are intended to work as part of a complete closed-loop motion system. The servo drive controls the motor while receiving feedback from the encoder. The controller can then compare commanded motion with actual motor movement and continuously adjust the motor’s operation.

This makes the motor suitable for applications where simply running at a constant speed is not enough.

A packaging machine, for example, may require the motor to accelerate rapidly, move a product or material to a specific position, decelerate, stop accurately, hold the position, and then repeat the cycle.

The low-inertia design of the MPL-B420P-MK74AA is particularly useful for this type of operating pattern.

The motor’s 5000 RPM speed rating provides the high-speed capability required by many automated machine axes, while the approximately 4.74 N·m continuous torque and 13.5 N·m peak torque provide the torque required for acceleration and transient load conditions.

The integrated 24 V DC brake adds another practical feature. The brake can be used as a holding mechanism when the motor is stopped, subject to the application’s mechanical and safety requirements.

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7. Low-Inertia Motor Design

The low-inertia construction is one of the most important characteristics of the MPL series.

A servo motor’s rotor must accelerate whenever the machine changes speed. Rotor inertia represents resistance to changes in rotational speed.

When rotor inertia is relatively low, the servo system can generally respond more quickly to changes in the commanded speed and position.

This is particularly valuable for:

• High-speed indexing
• Pick-and-place mechanisms
• Repetitive positioning
• Automated assembly
• Packaging machinery
• Cutting systems
• Material handling
• Rotary indexing tables
• High-speed transfer mechanisms

The practical benefit is most noticeable in machines that repeatedly accelerate and decelerate rather than machines that simply operate at one constant speed.

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8. 5000 RPM High-Speed Performance

The MPL-B420P-MK74AA has a rated speed of approximately 5000 RPM.

High rotational speed is useful when the machine needs rapid movement or when a mechanical transmission converts motor rotation into linear or rotary motion.

For example, when connected to a suitable ballscrew, pulley system or gearbox, a 5000 RPM servo motor can provide rapid axis movement while maintaining closed-loop control.

However, the actual operating speed should always be determined together with the mechanical transmission, load inertia, lubrication, bearing limitations and servo-drive configuration.

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9. Torque Characteristics

The motor provides approximately:

• 4.74 N·m continuous torque
• 13.5 N·m peak torque

Continuous torque is the important value for sustained load operation.

Peak torque is relevant to short-duration acceleration, deceleration and transient load requirements.

A machine should not be designed to operate continuously at the peak torque value.

When sizing the motor, the designer should calculate the actual load torque throughout the complete machine cycle.

For example, a machine may have relatively low torque requirements during constant-speed movement but require substantially more torque during acceleration.

The peak torque capability can provide additional short-term torque capacity for such conditions.

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10. Multi-Turn Absolute Feedback

The motor uses a multi-turn high-resolution absolute encoder.

The feedback system allows the servo drive to determine motor position with high resolution.

The multi-turn capability is particularly useful for applications where the motor shaft rotates through multiple revolutions while the machine still needs accurate positional information.

Typical applications include:

• Rotary positioning
• Ballscrew-driven linear axes
• Indexing mechanisms
• Coordinated motion
• Automated assembly
• Precision transfer systems
• Robotic positioning
• Machine-tool feed axes

The absolute feedback arrangement also makes the motor suitable for motion systems where reliable position information is an important part of the control architecture.

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11. Integrated 24 V DC Brake

One of the most important characteristics of the MPL-B420P-MK74AA is its 24 V DC integral brake.

The brake is intended primarily as a holding device rather than as the normal dynamic stopping mechanism for the machine.

During normal operation, the servo drive should generally control the motor’s acceleration and deceleration.

The brake can then be used to hold the motor shaft when required by the machine sequence.

This feature can be particularly useful in:

• Vertical axes
• Elevating mechanisms
• Z-axis machinery
• Material positioning systems
• Automated lifting mechanisms
• Machines where shaft movement must be prevented when the servo is disabled

The brake must be integrated according to the machine’s electrical and safety design.

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12. Keyless Shaft Configuration

The MPL-B420P-MK74AA uses a keyless shaft.

This configuration is useful for compatible clamping couplings and other mechanical transmission components designed for keyless servo shafts.

A keyless connection can provide a clean mechanical interface and can simplify certain machine designs.

When selecting the coupling, the following factors should be considered:

Mechanical Factor	Required Consideration
Shaft diameter	Must match the coupling
Torque capacity	Must exceed the application’s torque requirement
Maximum speed	Must be suitable for 5000 RPM operation
Radial load	Must remain within allowable limits
Axial load	Must remain within allowable limits
Misalignment	Must be compatible with the machine geometry
Balance	Important for high-speed operation
Installation clearance	Must allow proper coupling installation

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13. Right-Angle Rotatable Connector

The motor uses a right-angle SpeedTEC DIN connector.

The connector can be rotated through approximately 180 degrees.

This is particularly useful for machine builders because servo motors are often installed in confined areas.

Cable routing can be adjusted to avoid:

• Sharp cable bends
• Interference with machine covers
• Moving mechanisms
• Nearby motors
• Gearboxes
• Structural components

The connector arrangement therefore provides additional flexibility when designing the machine enclosure.

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14. Product Advantages

14.1 High Dynamic Response

The low-inertia rotor design supports rapid changes in motor speed.

This is useful for machines that perform repeated positioning operations.

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14.2 High-Speed Operation

The 5000 RPM rating provides a high-speed operating range for suitable mechanical systems.

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14.3 Precise Position Feedback

The multi-turn high-resolution absolute encoder provides detailed positional feedback.

This is suitable for precision positioning and coordinated motion.

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14.4 Integral Holding Brake

The 24 V DC brake provides an additional holding function.

This can be particularly valuable for vertical or gravity-loaded machine axes.

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14.5 Keyless Shaft

The keyless shaft provides compatibility with appropriate clamping-style couplings and mechanical transmission systems.

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14.6 Compact Frame

The 115 mm frame provides a relatively compact motor package for its torque and speed class.

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14.7 Flexible Connector Orientation

The rotatable right-angle connector makes cable routing easier in compact machine installations.

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14.8 Suitable for Repetitive Motion

The motor is well suited to repeated motion cycles involving acceleration, movement, deceleration and positioning.

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15. Typical Applications

15.1 Packaging Equipment

The motor is suitable for packaging machinery requiring fast and repeatable movement.

Typical applications include:

• Film feeding
• Bag forming
• Carton positioning
• Product indexing
• Label positioning
• Cutting
• Sealing mechanisms
• Rotary indexing
• Product transfer

The high-speed capability can support short machine cycle times, while the absolute feedback helps maintain repeatable positioning.

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15.2 Automated Assembly Machines

Automated assembly equipment frequently requires precise positioning of components.

The motor can be used for:

• Assembly axes
• Component positioning
• Insertion mechanisms
• Rotary indexing
• Transfer systems
• Inspection positioning
• Automated fastening systems

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15.3 Material Handling

Potential material-handling applications include:

• Conveyor positioning
• Transfer units
• Sorting systems
• Rotary transfer tables
• Product alignment
• Automated positioning
• Lifting and vertical motion systems

The integral brake can be particularly relevant when the axis must remain mechanically held after motion stops.

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15.4 Machine Tools

The motor can be considered for:

• Feed axes
• Positioning axes
• Tool positioning
• Auxiliary machine movement
• Rotary indexing
• Automated adjustment mechanisms

The actual selection depends on the required torque, speed, acceleration and machine-axis inertia.

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15.5 Robotics

The motor can be used for selected robotic and automated rotary axes.

Typical applications include:

• Rotary joints
• Positioning axes
• Automated transfer
• High-speed indexing
• Pick-and-place systems

The motor should be selected according to the actual robotic load and reflected inertia.

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15.6 Printing and Converting Equipment

Potential applications include:

• Web feeding
• Roller control
• Cutting
• Slitting
• Registration
• Material positioning
• Tension-related motion
• Rotary indexing

The high-speed operation and precise feedback make the motor suitable for coordinated motion systems.

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16. Five Recommended Models from the Same MPL Series

The following models are closely related to the MPL-B420P-MK74AA and can be considered when selecting a similar motor.

Model	Series	Voltage	Speed	Approx. Power	Continuous Torque	Peak Torque	Frame / Stack	Feedback	Shaft	Brake	Approx. Dimensions	Weight (kg)
MPL-B320P-MK74AA	MPL Low-Inertia	460 V	5000 RPM	Approx. 1.5 kW	Approx. 3.05 N·m	Approx. 7.91 N·m	100 / 50.8 mm	Multi-turn absolute	Keyless	24 V DC	Approx. 117 × 196 × 88 mm	Approx. 3.7
MPL-B330P-MK74AA	MPL Low-Inertia	460 V	5000 RPM	Approx. 1.8 kW	Approx. 4.18 N·m	Approx. 11.1 N·m	100 / 76.2 mm	Multi-turn absolute	Keyless	24 V DC	Approx. 117 × 222 × 88 mm	Approx. 4.6
MPL-B420P-MJ74AA	MPL Low-Inertia	460 V	5000 RPM	Approx. 1.9 kW	Approx. 4.74 N·m	Approx. 13.5 N·m	115 / 50.8 mm	Multi-turn absolute	Keyed	24 V DC	Approx. 133 × 187 × 98 mm	Approx. 5.5
MPL-B430P-MK74AA	MPL Low-Inertia	460 V	5000 RPM	Approx. 2.2 kW	Approx. 6.55 N·m	Approx. 19.8 N·m	115 / 76.2 mm	Multi-turn absolute	Keyless	24 V DC	Approx. 133 × 212 × 98 mm	Approx. 5.5
MPL-B4530K-MJ74AA	MPL Low-Inertia	460 V	4000 RPM	Approx. 3.5 kW class	Higher torque class	Higher peak torque class	130 / 76.2 mm	Multi-turn absolute	Keyed	24 V DC	Larger frame configuration	Approx. 10–15 kg class

The B320P and B330P options are useful where a smaller motor is sufficient.

The B420P configuration is suitable for the approximately 1.9 kW class.

The B430P provides greater torque while maintaining a closely related 115 mm frame concept.

The larger B4530K configuration is appropriate when considerably greater torque capacity is required.

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17. Five Closely Related B420P Models

If the goal is to remain within the same B420P motor size and output class, the following configurations are especially relevant.

Model	Voltage	Speed	Approx. Power	Continuous Torque	Peak Torque	Frame / Stack	Feedback	Shaft	Brake	Connector	Approx. Dimensions	Weight (kg)
MPL-B420P-MJ72AA	460 V	5000 RPM	1.9 kW	4.74 N·m	13.5 N·m	115 / 50.8 mm	Multi-turn absolute	Keyed	No brake	Right-angle DIN	Approx. 133 × 187 × 98 mm	Approx. 5.5
MPL-B420P-MJ74AA	460 V	5000 RPM	1.9 kW	4.74 N·m	13.5 N·m	115 / 50.8 mm	Multi-turn absolute	Keyed	24 V DC	Right-angle DIN	Approx. 133 × 187 × 98 mm	Approx. 5.5
MPL-B420P-MK72AA	460 V	5000 RPM	1.9 kW	4.74 N·m	13.5 N·m	115 / 50.8 mm	Multi-turn absolute	Keyless	No brake	Right-angle DIN	Approx. 133 × 187 × 98 mm	Approx. 5.5
MPL-B420P-MK74AA	460 V	5000 RPM	1.9 kW	4.74 N·m	13.5 N·m	115 / 50.8 mm	Multi-turn absolute	Keyless	24 V DC	Right-angle DIN	Approx. 133 × 187 × 98 mm	Approx. 5.5
MPL-B420P-RK74AA	460 V	5000 RPM	1.9 kW class	Similar B420P torque class	Similar B420P peak class	115 / 50.8 mm	Resolver	Keyless	24 V DC	Right-angle DIN	Approx. 133 × 187 × 98 mm	Approx. 5.5

Among these configurations, the most important differences are feedback type, shaft configuration and brake configuration.

For example, MJ74AA uses a keyed shaft, while MK74AA uses a keyless shaft.

Likewise, MK72AA and MK74AA have a major difference in the brake configuration.

For an actual replacement, these details should be checked carefully before ordering.

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18. Five Related Popular Models from the Same Brand Portfolio

Model	Product Family	Voltage	Speed	Approx. Power	Continuous Torque	Peak Torque	Frame / Stack	Feedback	Brake	Shaft	Approx. Dimensions	Weight (kg)
MPL-B310P-MJ74AA	MP-Series MPL	460 V	5000 RPM	Approx. 0.77 kW	Approx. 1.58 N·m	Approx. 3.61 N·m	100 / 25.4 mm	Multi-turn absolute	24 V DC	Keyed	Approx. 117 × 170 × 88 mm	Approx. 2.7
MPL-B320P-MK74AA	MP-Series MPL	460 V	5000 RPM	Approx. 1.5 kW	Approx. 3.05 N·m	Approx. 7.91 N·m	100 / 50.8 mm	Multi-turn absolute	24 V DC	Keyless	Approx. 117 × 196 × 88 mm	Approx. 3.7
MPL-B330P-MK74AA	MP-Series MPL	460 V	5000 RPM	Approx. 1.8 kW	Approx. 4.18 N·m	Approx. 11.1 N·m	100 / 76.2 mm	Multi-turn absolute	24 V DC	Keyless	Approx. 117 × 222 × 88 mm	Approx. 4.6
MPL-B430P-MK74AA	MP-Series MPL	460 V	5000 RPM	Approx. 2.2 kW	Approx. 6.55 N·m	Approx. 19.8 N·m	115 / 76.2 mm	Multi-turn absolute	24 V DC	Keyless	Approx. 133 × 212 × 98 mm	Approx. 5.5
MPL-B4530K-MJ74AA	MP-Series MPL	460 V class	4000 RPM	Approx. 3.5 kW class	Higher torque class	Higher peak torque class	130 / 76.2 mm	Multi-turn absolute	24 V DC	Keyed	Larger frame	Approx. 10–15 kg class

These models provide a practical range for applications requiring different levels of motor output.

The smaller B310P, B320P and B330P configurations can be considered when the load is lower and a smaller frame is preferred.

The B420P and B430P configurations provide higher torque capability within a relatively compact frame.

The B4530K is a substantially larger motor class and is better suited to applications with higher torque requirements.

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19. Comparison of B420P Configurations

Feature	MPL-B420P-MK72AA	MPL-B420P-MK74AA	MPL-B420P-MJ74AA
Frame	115 mm	115 mm	115 mm
Stack	50.8 mm	50.8 mm	50.8 mm
Rated Speed	5000 RPM	5000 RPM	5000 RPM
Approx. Power	1.9 kW	1.9 kW	1.9 kW
Continuous Torque	4.74 N·m	4.74 N·m	4.74 N·m
Peak Torque	13.5 N·m	13.5 N·m	13.5 N·m
Feedback	Multi-turn absolute	Multi-turn absolute	Multi-turn absolute
Shaft	Keyless	Keyless	Keyed
Brake	No brake	24 V DC brake	24 V DC brake
Connector	Right-angle DIN	Right-angle DIN	Right-angle DIN
Connector Rotation	180°	180°	180°
Approx. Weight	5.5 kg	5.5 kg	5.5 kg
Primary Difference	No brake	Brake + keyless shaft	Brake + keyed shaft

For applications where a holding brake is required, the MK74AA configuration provides an important functional difference compared with the MK72AA.

For applications where the shaft connection requires a traditional shaft key, the MJ74AA configuration may be more appropriate than the keyless MK74AA configuration.

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20. Applications Requiring a Holding Brake

The integral 24 V DC brake makes the MPL-B420P-MK74AA particularly relevant to machine axes where the motor needs to remain mechanically held after motion stops.

Examples include:

Vertical Z-Axis Equipment

A vertical machine axis may be affected by gravity.

When the servo motor is no longer actively producing torque, the mechanical load could move unless an appropriate holding mechanism is provided.

An integral motor brake can provide an additional holding function.

Lifting Equipment

Automated lifting and positioning equipment can use brake-equipped servo motors when the machine design requires the axis to remain stationary during specific operating conditions.

Automated Handling

Certain handling machines require a load to remain in position while another part of the machine performs an operation.

Machine-Tool Auxiliary Axes

Some auxiliary machine axes may benefit from a motor with a holding brake where movement after servo disablement is undesirable.

The brake should always be considered part of the overall machine safety and mechanical design rather than being treated as the only safety device.

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21. Environmental and Mechanical Considerations

The standard motor configuration is associated with an IP50-class enclosure.

IP50 protection is suitable for many clean industrial environments but does not provide the same environmental protection as a fully sealed motor.

Where the machine is exposed to:

• Dust
• Moisture
• Oil
• Coolant
• Washdown
• Chemical contamination
• High humidity

the appropriate motor sealing and installation configuration should be considered.

A shaft seal and appropriate environmental sealing arrangement may be required for applications demanding a higher level of protection.

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22. Installation Considerations

Before installing the MPL-B420P-MK74AA, the following items should be checked.

Installation Item	Recommended Check
Motor voltage	Confirm 460 V-class compatibility
Servo drive	Confirm motor/drive compatibility
Motor current	Confirm continuous and peak current requirements
Speed	Confirm required speed is within the motor’s operating range
Load torque	Confirm continuous load torque
Acceleration torque	Confirm peak torque requirement
Load inertia	Calculate reflected inertia
Feedback	Confirm absolute encoder compatibility
Brake	Provide correct 24 V DC brake control
Shaft	Confirm keyless coupling compatibility
Mounting	Confirm 115 mm frame mounting dimensions
Connector	Confirm correct motor cable and connector
Environment	Confirm enclosure protection is adequate
Temperature	Check ambient temperature and thermal conditions
Cable routing	Maintain suitable routing and bend radius
Vertical axis	Evaluate holding requirements carefully
Mechanical coupling	Check radial and axial loads
Grounding	Provide appropriate protective grounding
Vibration	Confirm machine vibration is within acceptable limits
Maintenance	Provide sufficient access to motor and connector

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23. Product Advantages in Industrial Automation

The MPL-B420P-MK74AA combines several features that are useful for modern automated machinery.

Its low-inertia design helps support fast acceleration and deceleration.

Its 5000 RPM speed supports high-speed machine movement.

Its 4.74 N·m continuous torque provides useful sustained torque capacity.

Its 13.5 N·m peak torque provides additional short-duration torque during dynamic motion.

Its multi-turn absolute feedback supports precise closed-loop positioning.

Its 24 V DC brake provides a holding function for suitable machine axes.

Its keyless shaft allows use with compatible clamping-type mechanical couplings.

Its rotatable right-angle connector provides additional flexibility when installing the motor in a compact machine.

Together, these characteristics make the motor suitable for demanding automated machinery where speed, repeatability and controlled movement are important.

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24. Technical Product Description

The MPL-B420P-MK74AA is a 460 V AC-class low-inertia brushless rotary servo motor with a 115 mm frame, 50.8 mm magnet stack and 5000 RPM rated speed.

The motor provides approximately 1.9 kW rated power, 4.74 N·m continuous torque and 13.5 N·m peak torque.

It incorporates a multi-turn high-resolution absolute encoder for closed-loop position feedback and uses a keyless shaft extension for mechanical connection.

A built-in 24 V DC brake provides an additional shaft-holding function for suitable applications.

The motor uses a right-angle SpeedTEC DIN connector with approximately 180-degree rotational adjustment, allowing greater flexibility during cable installation.

The MPL-B420P-MK74AA is suitable for packaging machinery, automated assembly, material handling, machine tools, printing and converting equipment, indexing systems, robotics and other industrial motion-control applications.

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25. Marketing-Oriented Product Introduction

The MPL-B420P-MK74AA is a high-performance low-inertia servo motor designed for precision industrial motion applications.

With a 5000 RPM operating class, approximately 1.9 kW rated power and 4.74 N·m continuous torque, the motor provides a useful combination of speed and torque in a compact 115 mm frame.

The multi-turn high-resolution absolute encoder supports accurate positioning and repeatable machine movement, while the low-inertia rotor design helps the motor respond quickly to changing speed commands.

The integrated 24 V DC brake adds a practical holding function for suitable machine axes, while the keyless shaft and rotatable right-angle connector provide flexibility during mechanical and electrical integration.

This combination makes the MPL-B420P-MK74AA particularly suitable for high-speed packaging, automated assembly, indexing, material handling and precision positioning applications.

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26. Detailed Parameter Summary

Category	Parameter	MPL-B420P-MK74AA
Identification	Model	MPL-B420P-MK74AA
Identification	Brand	Allen-Bradley
Identification	Product Family	MP-Series
Identification	Series	MPL Low-Inertia
Motor	Motor Type	Brushless AC Servo Motor
Motor	Motor Configuration	Low-Inertia
Electrical	Voltage	460 V AC
Electrical	Voltage Class	400/460 V AC class
Performance	Rated Speed	5000 RPM
Performance	Maximum Speed	5000 RPM
Performance	Rated Power	Approx. 1.9 kW
Performance	Continuous Torque	4.74 N·m
Performance	Peak Torque	13.5 N·m
Mechanical	Frame Size	115 mm
Mechanical	Stack Length	50.8 mm
Mechanical	Shaft	Keyless
Mechanical	Shaft Seal	Standard configuration without shaft seal
Feedback	Encoder	Multi-turn high-resolution absolute
Feedback	Feedback Type	Absolute multi-turn
Brake	Brake	Integral
Brake	Brake Voltage	24 V DC
Connector	Connector Type	SpeedTEC DIN
Connector	Connector Position	Right-angle
Connector	Rotation	180°
Mounting	Standard	IEC metric
Mounting	Mounting Type	Flange mount
Protection	Standard Enclosure	IP50
Dimensions	Approx. Length	187 mm
Dimensions	Approx. Width	133 mm
Dimensions	Approx. Height	98 mm
Dimensions	Approx. Overall Size	133 × 187 × 98 mm
Weight	Approx. Weight	5.5 kg
Rotor	Rotor Inertia	Approx. 0.00026–0.00030 kg·m²
Temperature	Typical Ambient Range	0 to 40 °C
Application	Main Use	Precision servo motion
Application	Typical Machinery	Packaging, assembly, indexing, material handling
Application	Vertical Axis	Suitable when brake requirements are correctly evaluated

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27. Final Product Summary

The MPL-B420P-MK74AA is a 5000 RPM, approximately 1.9 kW, 115 mm-frame low-inertia brushless servo motor equipped with a multi-turn high-resolution absolute encoder, keyless shaft and integral 24 V DC brake.

Its principal performance specifications include approximately 4.74 N·m continuous torque and 13.5 N·m peak torque.

The motor’s low-inertia design makes it well suited to machines with frequent acceleration and deceleration, while the 5000 RPM speed rating supports high-speed operation.

The absolute multi-turn feedback system is suitable for precision positioning and coordinated motion.

The integral 24 V DC brake is an important advantage for applications where the motor shaft needs to be held at standstill, especially when the axis is affected by gravity or when machine positioning must be maintained after servo motion has stopped.

The keyless shaft configuration provides flexibility for suitable mechanical couplings, while the right-angle 180-degree rotatable connector helps simplify cable routing in compact machine structures.

With an approximate overall envelope of 133 × 187 × 98 mm and an approximate weight of 5.5 kg, the motor offers a compact package for its performance class.

The most suitable applications include packaging machinery, automated assembly equipment, high-speed indexing machines, material handling systems, machine tools, printing and converting equipment, robotics and general industrial automation.

When selecting a replacement or equivalent model, the complete catalog number should be checked carefully. In particular, the feedback type, shaft configuration and brake configuration should match the requirements of the existing servo drive and mechanical system.