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MPL-B540K-SK74AA Low-Inertia Servo Motor – Complete Product Guide

1. Product Introduction

The MPL-B540K-SK74AA is a high-performance low-inertia rotary servo motor designed for industrial motion-control applications that require high rotational speed, strong torque output, accurate feedback, and fast dynamic response.

This model belongs to the MPL low-inertia servo motor family and uses a 460 V configuration, a 165 mm frame size, and a 101.6 mm magnet stack. It operates at 4000 rpm and provides approximately 19.4 N·m of continuous torque and 48.6 N·m of peak torque.

One of the defining features of this particular configuration is the combination of a keyless shaft and an integral 24 V DC brake. This makes the motor different from otherwise similar B540K models that use a keyed shaft or do not include a brake.

The motor also incorporates a single-turn high-resolution absolute encoder. This feedback arrangement is intended for precise servo positioning, speed regulation, acceleration control, and repeatable machine motion.

The connector is a right-angle SpeedTEC DIN type and can be rotated through 180 degrees. This is useful in machine installations where motor cable routing is restricted by surrounding components.

The model uses metric flange mounting and free mounting holes, Type FF. The exact product configuration identifies it as a 460 V, 4000 rpm, single-turn, keyless, brake-equipped servo motor.

2. Brand

Brand: Allen-Bradley

The MPL-B540K-SK74AA is part of the Allen-Bradley MP-Series motion-control product family.

For industrial procurement and replacement work, the complete catalog number is important because each section of the model number identifies a specific electrical or mechanical configuration.

The difference between a keyed and keyless shaft, for example, can determine whether the motor can be installed directly into an existing machine.

Likewise, the presence of the 24 V DC brake is an important selection characteristic, especially for vertical axes and applications that require the load to remain mechanically held after the servo drive is disabled.

3. Product Series

Series: MP-Series MPL Low-Inertia Servo Motors

Motor Type: Brushless rotary servo motor

Product Family: MPL Low Inertia

The MPL family is designed for industrial servo applications where fast acceleration, fast deceleration, high-speed operation, and accurate motion control are important.

The B540K configuration occupies a useful position within the MPL range. It provides 5.4 kW of continuous rated output while maintaining a 4000 rpm operating class.

The motor uses a 165 mm frame and 101.6 mm magnet stack, giving it considerably more torque capability than smaller MPL models while remaining more compact than the largest motors in the series.

The MPL family includes multiple combinations of speed, feedback, shaft, brake, connector, frame, and magnet-stack configurations.

4. Complete Model Identification

The catalog number MPL-B540K-SK74AA contains several configuration details.

Model Code	Meaning
MPL-B540K-SK74AA	Complete motor catalog number
MPL	Low-inertia servo motor family
B	460 V configuration
5	Frame size 165 mm
40	101.6 mm magnet stack
K	4000 rpm
S	Single-turn high-resolution encoder
K	Keyless shaft
7	SpeedTEC DIN right-angle connector
4	24 V DC brake
AA	Standard configuration suffix

The exact model selection information confirms the 460 V configuration, 165 mm frame, 101.6 mm stack, 4000 rpm speed, single-turn high-resolution feedback, keyless shaft, SpeedTEC DIN connector, and 24 V DC brake.

5. Main Technical Parameters

Parameter	Specification
Model	MPL-B540K-SK74AA
Brand	Allen-Bradley
Product Series	MPL Low Inertia
Product Type	Rotary servo motor
Motor Type	Brushless AC servo motor
Voltage Class	400 V AC
Armature Voltage	460 V
System Voltage Description	480 V AC class
Rated Speed	4000 rpm
Maximum Speed	4000 rpm
Rated Power	5.4 kW
Continuous Torque	19.4 N·m
Peak Torque	48.6 N·m
Frame Size	165 mm
Magnet Stack	101.6 mm
Feedback	Single-turn high-resolution absolute encoder
Feedback Resolution	Sin/Cos, 1024 cycles/rev
Feedback Protocol	Hiperface
Shaft	Keyless
Brake	Integral 24 V DC brake
Connector	SpeedTEC DIN
Connector Style	Right-angle
Connector Rotation	180° rotatable
Mounting	Metric flange mount
Mounting Holes	Free mounting holes, Type FF
Shaft Seal	No
Rotor Inertia	Approximately 0.00157 kg·m²
Maximum Operating Temperature	40 °C
Approximate Weight	About 19 kg with brake
Frame Reference	Frame 5
Stack Reference	40
Overall L × W × H	Use exact mechanical drawing
Main Application	Industrial servo motion control

The exact-model technical data specifies 4000 rpm, 19.4 N·m continuous torque, 48.6 N·m peak torque, 5.4 kW continuous output, 0.00157 kg·m² rotor inertia, 165 mm frame size, and 101.6 mm magnet stack.

6. Dimensions

The MPL-B540K-SK74AA uses a Frame 5 / 165 mm configuration and a 40 / 101.6 mm magnet stack.

Dimension	Specification
Model	MPL-B540K-SK74AA
Frame Size	165 mm
Frame Reference	Frame 5
Magnet Stack	101.6 mm
Stack Reference	40
Mounting Standard	IEC metric
Mounting Type	Flange mount
Mounting Holes	Free mounting holes, Type FF
Shaft Configuration	Keyless
Connector	Right-angle SpeedTEC DIN
Connector Rotation	180°
Overall Motor Length	Refer to mechanical drawing
Overall Motor Width	Refer to mechanical drawing
Overall Motor Height	Refer to mechanical drawing

The 165 mm dimension refers to the motor frame-size class and should not be treated as the total physical length of the motor.

Likewise, 101.6 mm identifies the magnet-stack length rather than the complete motor body length.

For machine design, exact mounting-hole positions, flange dimensions, shaft dimensions, connector clearance, and total motor envelope should be taken from the mechanical drawing. The product information confirms that a product drawing and 3D model are available for the exact model.

7. Weight

The SK74AA includes a motor-mounted 24 V DC brake, so its weight is higher than the comparable no-brake B540K configuration.

A practical figure for the brake-equipped configuration is approximately 19 kg.

Weight Information	Value
Model	MPL-B540K-SK74AA
Approximate Motor Weight	About 19 kg
Basic B540K No-Brake Class	About 15 kg
Integral Brake	Yes
Brake Voltage	24 V DC
Packaging Weight	Not included
Cable Weight	Not included
Shipping Weight	May be higher

The published motor-family data places the basic B540K configuration around the 15 kg class, while brake-equipped versions add the mechanical brake assembly. The exact SK74AA product data confirms that this model includes an integral 24 V brake.

Because the exact catalog-page data does not provide a definitive net shipping weight for every configuration, the approximately 19 kg figure should be treated as a practical reference rather than a certified shipping weight.

8. Rated Power

The MPL-B540K-SK74AA provides approximately 5.4 kW of continuous rated power.

This puts it into a substantial industrial servo power range suitable for demanding motion applications.

Power Parameter	Specification
Model	MPL-B540K-SK74AA
Continuous Rated Power	5.4 kW
Rated Speed	4000 rpm
Continuous Torque	19.4 N·m
Peak Torque	48.6 N·m
Armature Voltage	460 V
Voltage Class	400 V AC

The B540K motor family is listed at 5.4 kW, 4000 rpm, 19.4 N·m continuous torque, and 48.6 N·m peak torque.

9. Speed Performance

The rated speed of the MPL-B540K-SK74AA is 4000 rpm.

The maximum listed speed is also 4000 rpm.

This makes the motor particularly useful in applications where machine throughput depends on fast rotary movement and short positioning cycles.

Typical applications include:

• High-speed indexing.
• Rotary positioning.
• Packaging equipment.
• Conveyor synchronization.
• Ball-screw positioning.
• Automated assembly.
• Printing and converting equipment.
• Material handling.
• High-cycle machine axes.

The 4000 rpm class allows the motor to deliver substantial mechanical speed without requiring an additional high-speed mechanical transmission stage in some applications.

10. Torque Characteristics

The motor provides approximately 19.4 N·m of continuous torque and 48.6 N·m of peak torque.

Torque Parameter	Value
Model	MPL-B540K-SK74AA
Continuous Torque	19.4 N·m
Peak Torque	48.6 N·m
Rated Speed	4000 rpm
Rated Power	5.4 kW
Peak / Continuous Torque Ratio	Approx. 2.5

The continuous torque rating represents the motor’s sustained torque capability under the specified operating conditions.

The peak torque rating provides additional short-duration capability during acceleration, deceleration, rapid positioning, and transient load conditions.

The B540K family specifications confirm the 19.4 N·m continuous and 48.6 N·m peak torque values.

11. Rotor Inertia

The exact technical data gives the SK74AA a rotor inertia of approximately:

0.00157 kg·m²

Rotor inertia is important in servo applications because it affects the acceleration characteristics of the motor and the overall inertia ratio between the motor and the mechanical load.

A relatively low-inertia servo motor can respond quickly to acceleration and deceleration commands.

This makes the MPL-B540K-SK74AA suitable for machines with:

• Frequent start-stop cycles.
• Rapid indexing.
• Short positioning distances.
• High acceleration.
• High deceleration.
• Repeated direction changes.
• Electronic camming.
• High-cycle automation.

The family data also lists approximately 0.00147 kg·m² for the general B540K motor configuration, while the exact SK74AA technical data gives 0.00157 kg·m². For the exact model, the latter figure is preferable.

12. Feedback System

The MPL-B540K-SK74AA uses a single-turn high-resolution absolute encoder.

The encoder configuration is specified as Sin/Cos with 1024 cycles per revolution and Hiperface protocol.

Feedback Parameter	Specification
Model	MPL-B540K-SK74AA
Feedback Type	Absolute single-turn
Encoder Type	High-resolution encoder
Resolution	Sin/Cos, 1024 cycles/rev
Protocol	Hiperface
Position Range	Single mechanical revolution
Main Function	Position and velocity feedback
Application	Precision servo control

The feedback system provides the servo drive with detailed rotor-position information.

This is important for accurate positioning, velocity control, acceleration, deceleration, and coordinated multi-axis motion.

13. Single-Turn Absolute Feedback

The single-turn absolute configuration is particularly useful for applications where accurate rotor position within one mechanical revolution is required.

The encoder provides feedback information that allows the servo control system to regulate the motor accurately.

Typical applications include:

• Precision indexing.
• Pick-and-place machinery.
• Automated assembly.
• Rotary tables.
• Registration systems.
• Packaging machinery.
• Inspection systems.
• High-speed positioning axes.

The exact feedback type should always be matched when replacing an existing motor because changing from single-turn to multi-turn or incremental feedback can affect drive configuration and machine behavior.

14. Keyless Shaft

The SK74AA configuration uses a keyless shaft.

This is one of the most important mechanical characteristics of the model.

A keyless shaft is different from a conventional keyed shaft because it does not rely on a standard shaft key and keyway to transmit torque.

This arrangement is useful for applications using:

• Clamping couplings.
• Precision hubs.
• Shrink-fit transmission components.
• Special servo couplings.
• Precision mechanical transmission systems.
• Custom machine mechanisms.

Shaft Parameter	Specification
Model	MPL-B540K-SK74AA
Shaft Type	Keyless
Keyway	No conventional keyway
Coupling Type	Suitable clamping-style coupling
Main Benefit	Precision mechanical connection
Replacement Consideration	Shaft interface must match existing machine

The keyless shaft should be treated as a mandatory replacement-selection parameter.

A keyed B540K and a keyless B540K may have the same electrical performance but may not be mechanically interchangeable.

15. Integral 24 V DC Brake

The MPL-B540K-SK74AA includes an integral 24 V DC brake.

This is the major difference between the SK74AA and the corresponding SK72AA no-brake configuration.

Brake Parameter	Specification
Model	MPL-B540K-SK74AA
Integral Brake	Yes
Brake Voltage	24 V DC
Brake Configuration	Motor-mounted
Main Purpose	Holding / load retention
Typical Application	Vertical and gravity-loaded axes
Additional Weight	Yes

The brake can be particularly valuable in applications where the load must remain stationary when the servo drive is disabled.

This is especially relevant to vertical axes, lifting mechanisms, Z-axis machinery, and other systems where gravity can cause movement when motor torque is removed.

The brake should not be treated as a substitute for the complete machine safety system. The final braking and load-retention arrangement must be designed according to the machine’s safety requirements.

16. Brake Applications

The integral brake is useful in applications such as:

• Vertical positioning axes.
• Lift mechanisms.
• Z-axis machinery.
• Material handling.
• Automated storage equipment.
• Robotic vertical axes.
• Tool-changing mechanisms.
• Gravity-loaded linear stages.
• Machines where position must be retained after servo disable.

For a purely horizontal axis, a brake may not be necessary.

In that case, a no-brake version can sometimes be a simpler and lighter solution.

The SK74AA is therefore particularly useful when the machine requires both the B540K’s high-speed performance and a motor-mounted holding brake.

17. Connector Configuration

The motor uses a SpeedTEC DIN right-angle connector.

The connector can be rotated through 180 degrees.

This feature is helpful when the motor is installed inside a compact machine.

Connector Parameter	Specification
Model	MPL-B540K-SK74AA
Connector Type	SpeedTEC DIN
Connector Style	Right-angle
Rotation	180° rotatable
Connection	Quick-connect arrangement
Main Benefit	Flexible cable routing

The connector arrangement is part of the exact model configuration and should be considered when selecting replacement motors or cables.

18. Mounting Configuration

The MPL-B540K-SK74AA uses metric flange mounting.

The model is specified with free mounting holes, Type FF.

This makes it suitable for direct installation into industrial machine structures designed for the corresponding flange and shaft geometry.

Before installation, the following should be checked:

• Flange dimensions.
• Mounting-hole pattern.
• Shaft geometry.
• Shaft projection.
• Motor centerline.
• Connector clearance.
• Coupling dimensions.
• Cable routing.
• Motor orientation.

The frame size alone should never be used to determine whether a motor will physically fit a machine.

19. Main Product Advantages

High 4000 rpm Operating Speed

The 4000 rpm operating class makes the motor suitable for high-cycle machinery.

It can support fast positioning and rapid rotary movement when the mechanical system is designed for the corresponding speed.

5.4 kW Continuous Output

The 5.4 kW rating provides a useful combination of power and torque for demanding industrial machinery.

It is significantly more powerful than the smaller B520K class.

19.4 N·m Continuous Torque

The continuous torque capability allows the motor to operate under substantial sustained mechanical loads.

48.6 N·m Peak Torque

The peak torque capability supports short-duration acceleration and dynamic load changes.

This is particularly useful in machines with repeated acceleration and deceleration.

Low-Inertia Rotor

The low-inertia construction allows the motor to respond quickly to changing motion commands.

This is one of the major advantages of the MPL motor family.

Single-Turn High-Resolution Feedback

The absolute single-turn encoder provides accurate rotor-position feedback for servo control.

This is useful in precision positioning and synchronized motion applications.

Keyless Shaft

The keyless shaft provides a suitable interface for clamping-type couplings and other precision mechanical connections.

Integral 24 V DC Brake

The motor-mounted brake is especially useful for vertical or gravity-loaded axes.

Rotatable Right-Angle Connector

The 180-degree connector rotation gives the machine designer more freedom when routing motor cables.

Industrial Servo Construction

The motor is designed for demanding automated machinery rather than simple constant-speed motor applications.

20. Typical Applications

Packaging Machinery

The MPL-B540K-SK74AA can be used in packaging machinery requiring fast and repeatable servo movement.

Typical functions include:

• Indexing.
• Product positioning.
• Film handling.
• Cutting.
• Sealing.
• Label positioning.
• Conveyor synchronization.
• Rotary mechanisms.

The combination of high speed and absolute feedback is particularly useful in high-cycle packaging equipment.

Material Handling

Material-handling machinery frequently requires fast movement followed by accurate stopping.

The B540K motor’s torque and speed combination can be suitable for demanding conveyor, transfer, indexing, and positioning applications.

Vertical Axes

The integral brake makes this model especially interesting for vertical motion.

The brake can help retain a load when servo torque is removed, provided the complete machine safety design supports this function.

Ball-Screw Systems

When connected to a suitable ball screw, the motor can provide accurate linear motion.

Potential applications include:

• Automated positioning.
• Pick-and-place equipment.
• Linear transfer systems.
• Inspection systems.
• Assembly machinery.
• Machine-tool auxiliary axes.

Automated Assembly

Automated assembly systems often require rapid movement followed by precise positioning.

The low-inertia rotor and high-resolution feedback are well suited to repeated motion cycles.

Electronic Manufacturing Equipment

Electronic assembly and inspection machinery can require accurate, repeatable, high-speed motion.

The single-turn feedback system supports this type of controlled servo operation.

Printing and Converting

Printing, winding, slitting, and web-handling systems can require high-speed rotary movement and accurate synchronization.

The 4000 rpm operating class can be useful in these applications when correctly matched to the mechanical transmission.

Machine Tools

The motor can also be used in machine-tool motion systems where high-speed servo control is required.

The actual suitability depends on the machine load, axis inertia, acceleration requirements, duty cycle, and drive configuration.

21. Five Same-Series or Closely Related Models

The following five models are useful comparisons because they share the same B540K motor family or closely related configuration.

Model	Speed	Power	Continuous Torque	Peak Torque	Feedback	Shaft	Brake	Frame / Stack	Approx. Weight
MPL-B540K-SJ72AA	4000 rpm	5.4 kW	19.4 N·m	48.6 N·m	Single-turn absolute	Keyed	No	165 / 101.6 mm	Approx. 15 kg
MPL-B540K-SK72AA	4000 rpm	5.4 kW	19.4 N·m	48.6 N·m	Single-turn absolute	Keyless	No	165 / 101.6 mm	Approx. 15 kg
MPL-B540K-SK74AA	4000 rpm	5.4 kW	19.4 N·m	48.6 N·m	Single-turn absolute	Keyless	24 V DC	165 / 101.6 mm	Approx. 19 kg
MPL-B540K-MJ74AA	4000 rpm	5.4 kW	19.4 N·m	48.6 N·m	Multi-turn absolute	Keyed	24 V DC	165 / 101.6 mm	Approx. 19 kg
MPL-B540K-MK74AA	4000 rpm	5.4 kW	19.4 N·m	48.6 N·m	Multi-turn absolute	Keyless	24 V DC	165 / 101.6 mm	Approx. 19 kg

The main differences between these models are not necessarily power or torque. In many cases, the critical differences are feedback type, shaft configuration, and brake configuration.

For replacement purposes, these details can be more important than the nominal motor power.

22. MPL-B540K-SK74AA vs. MPL-B540K-SK72AA

The SK72AA is the closest comparison because the two configurations share the same basic motor performance but differ in brake configuration.

Parameter	MPL-B540K-SK74AA	MPL-B540K-SK72AA
Speed	4000 rpm	4000 rpm
Power	5.4 kW	5.4 kW
Continuous Torque	19.4 N·m	19.4 N·m
Peak Torque	48.6 N·m	48.6 N·m
Feedback	Single-turn	Single-turn
Shaft	Keyless	Keyless
Brake	24 V DC	None
Frame	165 mm	165 mm
Magnet Stack	101.6 mm	101.6 mm
Weight	Approx. 19 kg	Approx. 15 kg

The SK74AA should be selected when the motor-mounted brake is required.

The SK72AA is more suitable when the machine does not require an integral brake.

23. MPL-B540K-SK74AA vs. MPL-B540K-SJ74AA

The SJ74AA and SK74AA are closely related brake-equipped configurations.

Parameter	MPL-B540K-SK74AA	MPL-B540K-SJ74AA
Speed	4000 rpm	4000 rpm
Power	5.4 kW	5.4 kW
Continuous Torque	19.4 N·m	19.4 N·m
Peak Torque	48.6 N·m	48.6 N·m
Feedback	Single-turn	Single-turn
Shaft	Keyless	Keyed
Brake	24 V DC	24 V DC
Frame	165 mm	165 mm
Magnet Stack	101.6 mm	101.6 mm
Weight	Approx. 19 kg	Approx. 19 kg

The principal difference is the shaft.

The SK74AA is keyless.

The SJ74AA uses a keyed shaft.

This difference must be matched to the machine coupling.

24. Five Popular Same-Brand Models

The following models provide a useful range of motor sizes and performance levels within the same general product family.

Model	Rated Speed	Power	Continuous Torque	Peak Torque	Rotor Inertia	Dimensions Reference	Approx. Weight
MPL-B520K	4000 rpm	3.5 kW	10.7 N·m	23.2 N·m	0.000783 kg·m²	Smaller MPL frame / stack	9.8 kg
MPL-B540D	2000 rpm	3.4 kW	19.4 N·m	41.0 N·m	0.00147 kg·m²	165 mm frame	15 kg
MPL-B540K	4000 rpm	5.4 kW	19.4 N·m	48.6 N·m	Approx. 0.00147 kg·m²	165 mm frame / 101.6 mm stack	Approx. 15 kg
MPL-B560F	3000 rpm	5.5 kW	26.8 N·m	67.8 N·m	0.00213 kg·m²	Larger stack	20.2 kg
MPL-B580F	3000 rpm	7.1 kW	34.0 N·m	87.0 N·m	0.00289 kg·m²	Larger stack	25.4 kg

The published MPL motor data gives the principal performance values for these models, including speed, rated output, rotor inertia, continuous torque, peak torque, and available weight information.

25. MPL-B520K Comparison

The B520K is a lower-power alternative.

Parameter	MPL-B520K	MPL-B540K-SK74AA
Speed	4000 rpm	4000 rpm
Power	3.5 kW	5.4 kW
Continuous Torque	10.7 N·m	19.4 N·m
Peak Torque	23.2 N·m	48.6 N·m
Rotor Inertia	0.000783 kg·m²	Approx. 0.00157 kg·m²
Weight	9.8 kg	Approx. 19 kg
Brake	Configuration dependent	24 V DC
Shaft	Configuration dependent	Keyless

The B520K is appropriate when the machine requires less torque and power.

The B540K-SK74AA is more appropriate when the machine needs substantially more torque and also requires a motor-mounted brake.

26. MPL-B540D Comparison

The B540D operates at 2000 rpm rather than 4000 rpm.

Parameter	MPL-B540D	MPL-B540K-SK74AA
Rated Speed	2000 rpm	4000 rpm
Power	3.4 kW	5.4 kW
Continuous Torque	19.4 N·m	19.4 N·m
Peak Torque	41.0 N·m	48.6 N·m
Rotor Inertia	0.00147 kg·m²	0.00157 kg·m²
Frame	165 mm class	165 mm
Weight	Approx. 15 kg	Approx. 19 kg
Brake	Configuration dependent	24 V DC

The B540D is more oriented toward lower-speed operation.

The B540K-SK74AA is preferable where higher rotational speed and higher power are required.

27. MPL-B560F Comparison

The B560F provides higher continuous and peak torque while operating at 3000 rpm.

Parameter	MPL-B540K-SK74AA	MPL-B560F
Rated Speed	4000 rpm	3000 rpm
Power	5.4 kW	5.5 kW
Continuous Torque	19.4 N·m	26.8 N·m
Peak Torque	48.6 N·m	67.8 N·m
Rotor Inertia	0.00157 kg·m²	0.00213 kg·m²
Approx. Weight	19 kg	20.2 kg

The B560F is a better candidate for applications requiring more torque at a lower speed.

The B540K-SK74AA is more attractive when high-speed operation is a major requirement.

28. MPL-B580F Comparison

The B580F is a higher-output option.

Parameter	MPL-B540K-SK74AA	MPL-B580F
Rated Speed	4000 rpm	3000 rpm
Power	5.4 kW	7.1 kW
Continuous Torque	19.4 N·m	34.0 N·m
Peak Torque	48.6 N·m	87.0 N·m
Rotor Inertia	0.00157 kg·m²	0.00289 kg·m²
Approx. Weight	19 kg	25.4 kg

The B580F is more appropriate for heavier loads and higher torque requirements.

The B540K-SK74AA offers a better combination of speed and comparatively lower motor mass.

29. Servo Drive Compatibility

The B540K family is designed for use with compatible servo-drive systems.

The detailed technical data lists compatibility with several motion-control drive families, including:

• Kinetix 5500.
• Kinetix 6200.
• Kinetix 6500.
• Kinetix 6000.
• Kinetix 300.
• Kinetix 350.
• Kinetix 2000.
• Kinetix 7000.
• Ultra 3000.

These drive families should not be considered automatically interchangeable. The actual drive selection depends on motor current, voltage, feedback interface, power rating, control architecture, and machine requirements.

30. Mechanical Installation

The motor should be mounted to a rigid machine structure.

The mounting surface should be sufficiently flat and stable to prevent unnecessary mechanical stress on the motor housing.

The motor coupling should be correctly aligned.

Poor alignment can result in:

• Excessive bearing loading.
• Vibration.
• Coupling wear.
• Shaft stress.
• Positioning errors.
• Increased noise.
• Reduced motor service life.

Because this motor uses a keyless shaft, the coupling must be specifically compatible with the shaft arrangement.

31. Brake Wiring Considerations

The integral brake uses a 24 V DC configuration.

Brake control should be coordinated with the servo system and machine sequence.

The brake should not be treated as an ordinary motor power connection.

In many servo applications, the brake is primarily used as a holding device rather than as a repeated dynamic stopping device.

The exact brake-control sequence should be designed according to the applicable drive and machine-control requirements.

32. Vertical-Axis Applications

The integral brake is one of the strongest reasons to choose the SK74AA over the SK72AA.

For a vertical axis, the brake can help prevent the load from dropping when motor torque is removed.

Typical examples include:

• Z-axis machine tools.
• Vertical transfer mechanisms.
• Lift platforms.
• Vertical conveyors.
• Pick-and-place Z axes.
• Automated storage equipment.
• Vertical linear stages.

However, the brake does not eliminate the need for proper machine safety engineering.

The final system should consider load mass, gravitational force, brake holding capacity, emergency-stop behavior, mechanical redundancy, and applicable safety requirements.

33. Cable Routing

The right-angle connector helps reduce the amount of space needed behind the motor.

The connector can be rotated through 180 degrees, allowing the installer to choose a suitable cable exit direction.

Cable routing should avoid:

• Excessive bending.
• Mechanical tension.
• Abrasion.
• High-temperature surfaces.
• Moving machine components.
• Sharp edges.
• Excessive vibration.

The cable should have enough movement allowance where the machine axis itself moves.

34. Maintenance

The MPL-B540K-SK74AA is intended for industrial operation, but the complete motion system should still be inspected regularly.

Important inspection areas include:

• Mounting bolts.
• Shaft coupling.
• Mechanical alignment.
• Connector condition.
• Motor cable condition.
• Brake operation.
• Encoder feedback.
• Abnormal vibration.
• Motor temperature.
• Drive fault history.
• Mechanical load changes.

A sudden increase in temperature or vibration should be investigated rather than simply resetting the drive fault.

35. Replacement Checklist

When replacing an existing motor, the following characteristics should be checked carefully.

Replacement Item	MPL-B540K-SK74AA Requirement
Model	MPL-B540K-SK74AA
Voltage	460 V
Voltage Class	400 V AC
Speed	4000 rpm
Power	5.4 kW
Continuous Torque	19.4 N·m
Peak Torque	48.6 N·m
Frame	165 mm
Magnet Stack	101.6 mm
Feedback	Single-turn high-resolution
Shaft	Keyless
Brake	24 V DC integral brake
Connector	SpeedTEC DIN right-angle
Connector Rotation	180°
Mounting	Metric flange
Mounting Holes	Type FF
Rotor Inertia	Approx. 0.00157 kg·m²
Weight	Approx. 19 kg
Exact Overall Dimensions	Verify mechanical drawing

A replacement motor should not be selected by power rating alone.

The shaft type, feedback, brake, connector, frame, and mounting arrangement are equally important.

36. Application Selection Guide

Application	Suitability
High-speed indexing	Excellent
Packaging machinery	Excellent
Horizontal positioning	Excellent
Automated assembly	Excellent
Material handling	Very suitable
Ball-screw axes	Very suitable
Vertical axes	Excellent when properly engineered
Lift mechanisms	Very suitable
Printing/converting	Very suitable
Electronic assembly	Excellent
Precision positioning	Excellent
Heavy low-speed load	Consider a higher-torque model
Keyed coupling system	Not directly suitable
Keyless coupling system	Excellent

The table is intended as a practical first-stage selection guide. Detailed servo sizing should still be based on the actual machine motion profile.

37. Main Advantages at a Glance

Advantage	Explanation
4000 rpm operation	Supports high-speed machine cycles
5.4 kW power	Suitable for demanding industrial motion
19.4 N·m continuous torque	Strong sustained load capability
48.6 N·m peak torque	High short-duration acceleration capacity
Low rotor inertia	Supports fast dynamic response
Single-turn absolute feedback	Accurate position information
Keyless shaft	Suitable for clamping-type couplings
24 V DC brake	Useful for holding and vertical axes
180° rotatable connector	Flexible cable routing
165 mm frame	Substantial output in a practical industrial frame
Metric flange mounting	Suitable for industrial machine construction

38. Technical Characteristics in Practical Terms

The MPL-B540K-SK74AA can be viewed as a combination of four important characteristics:

High speed.

The 4000 rpm rating makes it appropriate for high-cycle machinery.

High dynamic capability.

The 19.4 N·m continuous and 48.6 N·m peak torque ratings provide a useful combination of continuous and transient performance.

Precision feedback.

The single-turn high-resolution encoder supports accurate servo control.

Mechanical holding capability.

The integral 24 V DC brake provides an important advantage for applications where the motor must hold a load after servo torque is removed.

These characteristics make the SK74AA particularly attractive for demanding automated machinery.

39. Complete Technical Summary

Technical Category	MPL-B540K-SK74AA
Model	MPL-B540K-SK74AA
Brand	Allen-Bradley
Product Family	MP-Series
Product Series	MPL Low Inertia
Motor Type	Brushless rotary servo motor
Voltage	460 V armature
Voltage Class	400 V AC
Rated Speed	4000 rpm
Maximum Speed	4000 rpm
Rated Power	5.4 kW
Continuous Torque	19.4 N·m
Peak Torque	48.6 N·m
Frame Size	165 mm
Magnet Stack	101.6 mm
Feedback	Single-turn high-resolution absolute encoder
Feedback Resolution	Sin/Cos, 1024 cycles/rev
Feedback Protocol	Hiperface
Shaft	Keyless
Integral Brake	Yes
Brake Voltage	24 V DC
Connector	SpeedTEC DIN
Connector Type	Right-angle
Connector Rotation	180°
Mounting	Metric flange
Mounting Holes	Type FF
Shaft Seal	No
Rotor Inertia	Approx. 0.00157 kg·m²
Maximum Operating Temperature	40 °C
Approximate Weight	About 19 kg
Frame Reference	Frame 5
Stack Reference	40
Overall Dimensions	Exact L × W × H from mechanical drawing
Typical Application	Industrial servo motion control

The exact-model data confirms the principal electrical, feedback, shaft, brake, connector, mounting, and physical configuration characteristics listed above.

40. Final Product Assessment

The MPL-B540K-SK74AA is a strong industrial servo motor for applications requiring high speed, substantial torque, precise feedback, and a motor-mounted holding brake.

Its 4000 rpm rating makes it particularly useful for high-cycle machinery.

The 5.4 kW continuous output provides a substantial power level for industrial automation, while the 19.4 N·m continuous torque and 48.6 N·m peak torque provide a good balance between continuous load capability and dynamic acceleration performance.

The low-inertia rotor supports rapid changes in speed and direction, which is valuable in machines with frequent indexing and short positioning cycles.

The single-turn high-resolution absolute encoder provides accurate feedback for servo control.

The keyless shaft is well suited to clamping-style couplings and precision mechanical interfaces.

The integral 24 V DC brake is an especially important feature for vertical axes, lifting mechanisms, and other applications where the motor must help retain the mechanical load when servo torque is removed.

The right-angle SpeedTEC DIN connector, with 180-degree rotational flexibility, also makes the motor easier to integrate into compact machine structures.

From a replacement perspective, the most important characteristics are not only the 5.4 kW rating. The complete configuration must be matched, including 4000 rpm speed, single-turn feedback, keyless shaft, 24 V DC brake, 165 mm frame, 101.6 mm magnet stack, connector arrangement, and mounting dimensions.

Overall, the MPL-B540K-SK74AA is best suited to high-performance automated machinery where fast motion, precise positioning, strong torque, and mechanical load holding are all important.

For applications requiring the same basic motor performance without a brake, the SK72AA is the closest alternative.

For applications requiring a keyed shaft instead of a keyless shaft, a corresponding J-suffix configuration should be considered.

For applications requiring greater torque rather than higher speed, larger MPL configurations such as the B560F or B580F may be more appropriate.