Company Information
E-mail		[email protected]
Mobile		+8615980777398
Whatsapp		+8615980777398
WeChat		15980777398

1. Product Overview

The Allen-Bradley 20P41AD667RA0NNN is a high-power regenerative DC drive in the PowerFlex DC series, designed for large industrial DC motor applications where high armature current, controlled acceleration, regenerative braking, reversing capability, and stable speed regulation are required.

This model is rated at 667 A and 400 HP, equivalent to approximately 298 kW, making it one of the larger Frame C drives in the 460/480 V PowerFlex DC range.

The drive is designed for a 480 VAC, three-phase input, uses a 6-pulse input configuration, and provides four-quadrant regenerative operation. Its standard configuration includes an IP20 / NEMA/UL Type Open enclosure, conformal coating, a blank HIM plate, a user manual, and no communication module.

The 20P41AD667RA0NNN is particularly suited to machinery with substantial mechanical inertia or applications where the motor needs to accelerate, decelerate, reverse, and regenerate repeatedly.

Typical application areas include large winding and unwinding machines, paper and converting equipment, metal-processing machinery, heavy conveyors, material-handling systems, large process lines, and industrial machinery using high-power DC motors.

---

2. Brand and Product Series

Item	Specification
Brand	Allen-Bradley
Product Series	PowerFlex DC
Product Type	Digital Regenerative DC Drive
Catalog Number	20P41AD667RA0NNN
Voltage Class	460/480 VAC
Input Voltage	480 VAC, 3-phase
Input Configuration	6-pulse
Output Current	667 A
Motor Rating	400 HP
Motor Power	Approximately 298 kW
Frame Size	Frame C
Motor Operation	Four-quadrant regenerative
Field Supply	Single-phase regulated
Enclosure	IP20, NEMA/UL Type Open
Conformal Coating	Yes
HIM Configuration	Blank plate / no HIM
Communication Module	None in stated configuration
Approx. Dimensions	521 × 511 × 416 mm
Approx. Weight	61 kg
Main Application	High-power industrial DC motor control

The product-selection information identifies the 20P41AD667RA0NNN as a 480 VAC, three-phase, 667 A, 400 HP PowerFlex DC drive, with Frame C construction and four-quadrant regenerative operation.

The Frame C mechanical data gives an approximate size of 521 mm high × 511 mm wide × 416 mm deep, with a drive weight of approximately 61 kg.

---

3. Main Technical Parameters

Parameter	Specification
Brand	Allen-Bradley
Series	PowerFlex DC
Catalog Number	20P41AD667RA0NNN
Drive Type	Regenerative DC Drive
Input Voltage	480 VAC class
Input Phase	3-phase
Input Type	6-pulse
Rated Output Current	667 A
Normal-Duty Motor Rating	400 HP
Motor Power	Approximately 298 kW
Motor Operation	Four-quadrant regenerative
Frame Size	Frame C
Field Supply	Single-phase regulated
Enclosure Rating	IP20
Enclosure Type	NEMA/UL Type Open
Conformal Coating	Yes
HIM	Blank plate / no HIM
Communication Module	None in stated configuration
Feedback Capability	DC tachometer and encoder feedback
Digital I/O	Up to 12 digital inputs/outputs
Analog Inputs	Up to 3
Analog Outputs	Up to 4
Approx. Height	521 mm
Approx. Width	511 mm
Approx. Depth	416 mm
Approx. Dimensions	521 × 511 × 416 mm
Approx. Drive Weight	61 kg
Approx. Packaged Weight	83 kg
Typical Installation	Electrical cabinet / protected enclosure
Main Motor Type	Industrial DC motor
Main Application	High-power DC motor speed and torque control

The 667 A model is listed as a Frame C regenerative drive with a 400 HP / approximately 298 kW normal-duty rating. The product architecture also provides embedded DC tachometer and encoder feedback capability and extensive I/O for machine integration.

---

4. Product Introduction

The 20P41AD667RA0NNN is designed for industrial machines that require a high-capacity DC motor drive.

With a 667 A output rating, the drive is intended for considerably larger motors than the smaller PowerFlex DC models.

A drive at this power level is normally found in large production machinery rather than compact standalone equipment.

The main purpose of the drive is to convert the incoming three-phase AC supply into controlled DC motor power while regulating motor speed, torque, acceleration, deceleration, and regenerative operation.

The drive is particularly valuable where the machine has significant inertia or where the motor must repeatedly move between motoring and generating conditions.

For example, a large winding machine may accelerate a heavy roll, operate at a stable production speed, and then decelerate the roll during a production cycle.

During deceleration, the mechanical energy stored in the rotating system can drive the motor.

The regenerative capability of the 20P41AD667RA0NNN allows the drive to control this operating condition instead of treating the motor simply as a disconnected load.

---

5. 667 A High-Current Capacity

The 667 A output current rating is the defining electrical characteristic of this model.

A current rating of this magnitude places the drive firmly within the high-power industrial DC-drive category.

The high current capability allows the drive to supply large DC motors that require substantial armature current.

This is especially important during acceleration.

Large industrial machines often have considerable mechanical inertia.

A large roll, drum, flywheel, conveyor, or processing system can require significant torque to accelerate from zero speed.

The drive therefore needs to provide controlled current without causing unstable motor operation.

The 667 A capacity gives this model a substantial operating range for heavy industrial DC motor applications.

---

6. 400 HP / 298 kW Motor Rating

The 20P41AD667RA0NNN is rated for approximately 400 HP, equivalent to approximately 298 kW.

This places the drive in a high-power industrial motor class.

A motor of this size can be used in large production machinery, material-handling systems, winding equipment, metal-processing equipment, paper machinery, and other heavy industrial applications.

The horsepower rating should not be used as the only motor-selection criterion.

The motor armature voltage, armature current, field voltage, field current, speed range, feedback method, acceleration requirements, and duty cycle should all be considered.

A 400 HP motor with an unusual armature voltage or current requirement may require a different drive configuration.

---

7. 480 VAC Three-Phase Input

The drive is designed for a 480 VAC, three-phase input.

This is a common industrial power class for large motor-control equipment.

The three-phase AC input is converted by the drive into controlled DC power for the motor armature.

For a high-power drive, the incoming electrical system must be carefully designed.

Important considerations include:

• Incoming voltage.
• Frequency.
• Short-circuit current.
• Disconnect equipment.
• Protective devices.
• Grounding.
• Conductor sizing.
• Line impedance.
• Harmonic considerations.
• Cabinet thermal conditions.

The drive rating and the incoming electrical infrastructure must therefore be considered as one complete system.

---

8. Six-Pulse Input Architecture

The 20P41AD667RA0NNN uses a 6-pulse input configuration.

A six-pulse rectifier arrangement is a well-established industrial method for converting three-phase AC power into DC power.

The architecture provides a practical and robust power-conversion structure for DC motor drives.

For high-current industrial applications, the complete electrical installation should also take into consideration line reactors, protective devices, grounding, cable routing, and applicable electrical requirements.

The PowerFlex DC selection information specifically identifies the 667 A model as a 6-pulse regenerative drive.

---

9. Four-Quadrant Regenerative Operation

One of the most important features of the 20P41AD667RA0NNN is its four-quadrant regenerative operation.

Four-quadrant operation allows the drive to control both forward and reverse motor operation while also managing regenerative conditions.

The four basic operating states can be described as:

1. Forward motoring.
2. Forward regeneration.
3. Reverse motoring.
4. Reverse regeneration.

This is particularly useful for machinery that frequently accelerates and decelerates.

It is also valuable for reversing machinery where the motor must change direction in a controlled manner.

---

10. Regenerative Braking

Regenerative braking is particularly important for large high-inertia machines.

Imagine a large winding roll rotating at high speed.

The roll stores mechanical energy while it is rotating.

When the machine needs to stop or reduce speed, that energy must be controlled.

The motor can enter a generating condition during deceleration.

A regenerative drive can manage this condition while providing controlled braking torque.

This makes regenerative operation highly relevant to:

• Large winding systems.
• Unwinding systems.
• Large conveyors.
• Reversing machinery.
• High-inertia rotating equipment.
• Large material-handling equipment.
• Cyclic production machinery.

---

11. Frame C Construction

The 20P41AD667RA0NNN uses a Frame C mechanical design.

Frame size is important because it determines the physical envelope, mounting arrangement, cooling arrangement, and service requirements of the drive.

The 667 A model shares the Frame C category with the 495 A model.

The next major step in the 480 V regenerative PowerFlex DC range is the 830 A model, which moves into Frame D.

This makes the 20P41AD667RA0NNN an important high-current Frame C model within the product family.

---

12. Dimensions and Weight

The approximate dimensions of the Frame C drive are:

• Height: 521 mm
• Width: 511 mm
• Depth: 416 mm

The approximate drive weight is:

• 61 kg

The approximate packaged weight is:

• 83 kg

The physical dimensions and weight are important when designing the electrical cabinet and planning installation.

The cabinet must have sufficient structural capacity for the drive and associated components.

Adequate clearance should also be provided for electrical connections, cooling airflow, inspection, and service access.

---

13. IP20 / NEMA/UL Type Open Enclosure

The drive uses an IP20, NEMA/UL Type Open enclosure configuration.

This means it is intended to be installed inside an appropriate electrical enclosure or protected industrial cabinet.

It should not be considered a weatherproof or washdown-rated drive.

The surrounding cabinet must provide suitable protection against environmental contamination.

The cabinet should also be designed around the thermal requirements of a high-power 667 A drive.

---

14. Conformal-Coated Construction

The 20P41AD667RA0NNN configuration includes conformal coating.

Conformal coating provides an additional protective layer for electronic assemblies.

This can be useful in industrial environments where humidity, dust, or airborne contaminants may create additional stress on electronic equipment.

However, conformal coating does not replace proper enclosure design.

The complete installation must still provide appropriate environmental and thermal protection.

---

15. Regulated Field Supply

The drive uses a single-phase regulated field supply.

The field circuit is an important part of a DC motor system.

Unlike a simple AC induction motor drive, a DC motor system has both armature and field circuits.

The drive therefore has to manage the motor field as part of the overall motor-control system.

Field voltage and field current should be checked against the motor nameplate before commissioning.

---

16. Feedback Capability

The PowerFlex DC platform provides DC tachometer and encoder feedback capability as part of its standard control architecture.

Feedback is particularly important when accurate motor-speed regulation is required.

For example, a winding machine may need to maintain a stable line speed.

A paper-processing machine may require coordinated speed between multiple sections.

A metal-processing machine may need stable speed under changing mechanical loads.

Feedback gives the control system additional information about actual motor or machine speed.

This can improve the ability of the drive system to maintain the required operating condition.

The 667 A product information specifically identifies embedded DC tachometer and encoder feedback capability.

---

17. I/O Capability

The PowerFlex DC architecture provides extensive I/O capability for industrial integration.

The platform supports up to approximately:

• 12 digital inputs/outputs
• 3 analog inputs
• 4 analog outputs

This provides considerable flexibility for machine integration.

For example, a PLC can issue a speed reference while receiving drive status and fault information.

Analog inputs can be used for process references or external feedback signals.

Digital inputs and outputs can be used for commands, interlocks, status signals, and machine-control functions.

The exact installed configuration should always be checked when planning a particular control system.

---

18. Main Applications

The 20P41AD667RA0NNN can be used in a wide range of high-power industrial applications.

Typical applications include:

• Large winding machines.
• Unwinding machines.
• Steel-processing equipment.
• Metal-processing lines.
• Large paper machines.
• Printing and converting machinery.
• Large conveyors.
• Heavy material-handling equipment.
• Large rollers.
• High-inertia machinery.
• Continuous production lines.
• Reversing machinery.
• Large DC motor retrofit projects.

---

19. Winding Machine Applications

Winding machinery is one of the most suitable applications for a high-power regenerative DC drive.

A large winding machine can contain a roll with considerable mass.

The motor needs to accelerate the roll smoothly.

During production, the drive must maintain stable speed and torque.

As the roll diameter changes, the machine-control system may need to continuously adjust motor operation.

During deceleration, the rotating roll can drive the motor.

The regenerative drive can then control the motor as it enters a generating condition.

The 667 A capacity makes the model suitable for winding systems substantially larger than those served by the smaller PowerFlex DC models.

---

20. Unwinding Applications

Unwinding systems have different torque requirements from winding systems.

The material is pulled from a roll, causing the roll to rotate.

The motor may need to apply controlled braking torque to prevent excessive roll speed.

This can result in regenerative operating conditions.

A four-quadrant drive provides the control architecture needed to manage these changes.

For large unwind systems using DC motors, the 20P41AD667RA0NNN can provide substantial current and regenerative capacity.

---

21. Tension-Control Applications

Tension control is important in industries processing continuous materials.

Examples include:

• Paper.
• Plastic film.
• Foil.
• Wire.
• Cable.
• Textile materials.
• Metal strip.

The motor torque and speed need to be coordinated with the line speed.

A DC drive with feedback capability can form part of a closed-loop tension-control system.

The exact tension-control strategy depends on the machine architecture and the sensors used.

---

22. Metal-Processing Applications

Large DC motors have been used extensively in industrial metal-processing equipment.

Such machinery can require high torque and stable speed.

The 20P41AD667RA0NNN provides the current capacity needed for large DC motor applications around the 400 HP class.

Its regenerative operation is also useful where the machine experiences frequent acceleration and deceleration.

---

23. Paper-Making Applications

Large paper-processing systems can contain:

• Roll drives.
• Winder sections.
• Unwinder sections.
• Feed rolls.
• Process rolls.
• Tension-control sections.

These machines can involve high rotational inertia.

The drive’s regenerative capability can therefore be useful for controlled braking and deceleration.

The feedback capability is also relevant where stable speed and coordination between machine sections are required.

---

24. Printing and Converting Applications

Large printing and converting systems can use multiple motor sections.

Each section may need to maintain a specific speed relationship with the others.

A DC drive can provide controlled motor operation while the machine controller coordinates the process.

For larger machines, the 667 A drive provides enough current capacity for substantial DC motors.

---

25. Large Conveyor Applications

Large conveyors may require high starting torque.

This is particularly true when the conveyor is heavily loaded.

The motor must accelerate the belt and material mass without excessive mechanical shock.

The drive can provide controlled acceleration and speed regulation.

If the conveyor has substantial inertia or a downhill load, regenerative braking can also become an important operating function.

---

26. Heavy Material Handling

Heavy material-handling systems can involve frequent movement, stopping, and reversing.

The four-quadrant capability of the drive is useful for this type of operation.

The motor can operate in motoring mode during acceleration and transition into regenerative operation during controlled deceleration.

This makes the drive suitable for demanding cyclic industrial machinery when the motor and mechanical system meet the applicable requirements.

---

27. Large Reversing Machinery

Some industrial machines need to operate in both directions.

Examples include:

• Reversing rollers.
• Processing equipment.
• Material-handling machinery.
• Certain winding systems.
• Large machine-tool systems.
• Specialized production machinery.

Four-quadrant operation allows the drive to manage forward and reverse operation while controlling the associated regenerative states.

---

28. High-Inertia Loads

High-inertia machinery is one of the strongest application areas for regenerative drives.

The higher the rotating mass, the more energy is stored while the machine is running.

When the machine decelerates, this energy has to go somewhere.

A regenerative drive provides a controlled electrical path for the generated energy.

This allows the drive to provide controlled deceleration without relying solely on mechanical braking.

---

29. Main Product Advantages

29.1 High 667 A Output Rating

The 667 A output rating allows the drive to handle very large DC motor loads.

This is the primary reason the model is positioned in the high-power section of the PowerFlex DC family.

---

29.2 400 HP Motor Rating

The approximately 400 HP / 298 kW rating allows the drive to control substantial industrial motors.

This makes it suitable for large production machinery.

---

29.3 Four-Quadrant Regenerative Control

Four-quadrant operation provides both motoring and regeneration in forward and reverse directions.

This is particularly valuable for cyclic and reversing machines.

---

29.4 Regenerative Braking

Regenerative braking provides controlled deceleration for high-inertia loads.

This can be particularly useful for winding machines, conveyors, and large rotating equipment.

---

29.5 Feedback Capability

Embedded encoder and DC tachometer feedback capability supports applications requiring accurate speed regulation.

This is useful for tension control, synchronization, winding, and other precision processes.

---

29.6 Extensive I/O

The available digital and analog I/O provides flexibility when integrating the drive into an existing automation system.

---

29.7 Frame C High-Power Construction

The Frame C mechanical design provides a high-current platform while maintaining a defined mechanical envelope.

---

29.8 Conformal-Coated Electronics

The conformal-coated configuration adds an additional layer of protection to the electronic assemblies.

---

30. Five Recommended Same-Series Models

The following five models are closely related PowerFlex DC regenerative models.

They are useful when selecting a drive based on motor size and current requirements.

Model	Input Voltage	Output Current	Motor Rating	Motor Power	Frame	Operation	Approx. Dimensions	Approx. Weight
20P41AD495RA0NNN	480 VAC, 3 PH	495 A	300 HP	224 kW	C	Four-quadrant regenerative	521 × 511 × 416 mm	61 kg
20P41AD667RA0NNN	480 VAC, 3 PH	667 A	400 HP	298 kW	C	Four-quadrant regenerative	521 × 511 × 416 mm	61 kg
20P41AD830RA0NNN	480 VAC, 3 PH	830 A	500 HP	373 kW	D	Four-quadrant regenerative	Configuration-dependent; verify mechanical drawing	Configuration-dependent
20P41AD996RA0NNN	480 VAC, 3 PH	996 A	600 HP	447 kW	D	Four-quadrant regenerative	Configuration-dependent; verify mechanical drawing	Configuration-dependent
20P41AD1K1RA0NNN	480 VAC, 3 PH	1162 A	700 HP	552 kW	D	Four-quadrant regenerative	Configuration-dependent; verify mechanical drawing	Configuration-dependent

The PowerFlex DC selection table identifies the 495 A and 667 A models as Frame C, followed by the 830 A and larger models in Frame D.

The 667 A model therefore sits between the 300 HP and 500 HP classes in the high-power 480 V regenerative range.

---

31. Same-Series Model Comparison

Model	Current	HP	kW	Frame	Regenerative Operation	Approx. Dimensions	Approx. Weight
20P41AD495RA0NNN	495 A	300 HP	224 kW	C	Yes	521 × 511 × 416 mm	61 kg
20P41AD667RA0NNN	667 A	400 HP	298 kW	C	Yes	521 × 511 × 416 mm	61 kg
20P41AD830RA0NNN	830 A	500 HP	373 kW	D	Yes	Configuration-dependent	Configuration-dependent
20P41AD996RA0NNN	996 A	600 HP	447 kW	D	Yes	Configuration-dependent	Configuration-dependent
20P41AD1K1RA0NNN	1162 A	700 HP	552 kW	D	Yes	Configuration-dependent	Configuration-dependent

The 495 A and 667 A models share the Frame C mechanical category, while the larger 830 A and above models move into Frame D.

---

32. Five Additional Closely Related Models

For a broader comparison, the following models are also part of the 460/480 V regenerative PowerFlex DC family.

Model	Output Current	Motor Rating	Motor Power	Frame	Input	Approx. Dimensions	Approx. Weight
20P41AD250RA0NNN	250 A	150 HP	112 kW	B	480 VAC, 3 PH	Approx. 311 × 388 × 350 mm	Approx. 29.5 kg
20P41AD330RA0NNN	330 A	200 HP	149 kW	B	480 VAC, 3 PH	Approx. 311 × 388 × 350 mm	Approx. 32 kg
20P41AD412RA0NNN	412 A	250 HP	187 kW	B	480 VAC, 3 PH	Approx. 311 × 388 × 350 mm	Approx. 32 kg
20P41AD495RA0NNN	495 A	300 HP	224 kW	C	480 VAC, 3 PH	521 × 511 × 416 mm	61 kg
20P41AD667RA0NNN	667 A	400 HP	298 kW	C	480 VAC, 3 PH	521 × 511 × 416 mm	61 kg

This group is useful for applications where the motor rating is between approximately 150 HP and 400 HP.

The 667 A model provides a substantial increase in current capacity compared with the 495 A model while retaining the Frame C platform.

---

33. Five Popular Related Models From the Same Brand

The following are popular products from other PowerFlex families.

They are related products at the industrial-drive level, but they are not direct substitutes for a 667 A regenerative DC drive.

Model	Product Family	Drive Type	Voltage Class	Current / Power Class	Motor Type	Approx. Dimensions	Approx. Weight
25B-D017N114	PowerFlex 525	Compact AC VFD	480 VAC class	Approx. 17 A / 10 HP class	AC motor	Configuration-dependent	Configuration-dependent
25B-D030N114	PowerFlex 525	Compact AC VFD	480 VAC class	Approx. 30 A / 15 HP class	AC motor	Configuration-dependent	Configuration-dependent
20G11ND077AA0NNNNN	PowerFlex 755	Architecture AC Drive	480 VAC class	Approx. 77 A / 50 HP class	AC motor	Configuration-dependent	Configuration-dependent
20G11ND156AA0NNNNN	PowerFlex 755	Architecture AC Drive	480 VAC class	Approx. 156 A / 100 HP class	AC motor	Configuration-dependent	Configuration-dependent
22F-D060N103	PowerFlex 4M	Compact AC Drive	480 VAC class	Approx. 6 A / 3 HP class	AC motor	Configuration-dependent	Configuration-dependent

These products can be useful for new machine designs where an AC motor is being considered.

For an existing machine using a 400 HP DC motor, however, changing to an AC drive would normally require a much broader engineering review involving the motor, mechanical transmission, braking system, feedback system, PLC logic, cabinet, and machine-control strategy.

---

34. PowerFlex DC Versus PowerFlex AC

The PowerFlex DC and PowerFlex AC product families are designed around different motor technologies.

The 20P41AD667RA0NNN is specifically intended for a DC motor system.

A DC motor typically has an armature circuit and a field circuit.

The DC drive controls these elements as part of the motor-control process.

An AC variable-frequency drive, by comparison, controls an AC motor by varying the electrical characteristics supplied to the motor.

Therefore, a PowerFlex 525 or PowerFlex 755 should not be selected as a direct catalog-number replacement for the 20P41AD667RA0NNN.

The appropriate choice depends on whether the machine will continue using the existing DC motor or will be converted to an AC motor system.

---

35. Motor Selection and Matching

For a 667 A drive, motor matching should be performed carefully.

The following motor parameters are particularly important:

Motor Parameter	Importance
Armature Voltage	Determines compatibility with the drive output
Armature Current	Critical for matching the 667 A drive rating
Motor HP	Establishes the general power class
Motor kW	Provides metric power reference
Rated Speed	Defines normal operating speed
Maximum Speed	Important for drive configuration
Field Voltage	Required for field-supply configuration
Field Current	Required for field capacity
Feedback Device	Determines speed-feedback arrangement
Duty Cycle	Affects thermal loading
Acceleration Time	Influences current and torque requirements
Deceleration Time	Influences regeneration
Reversing Requirement	Determines operating mode requirements
Load Inertia	Important for acceleration and braking
Mechanical Coupling	Affects torque transmission
Cooling Arrangement	Affects continuous motor capability

The actual motor nameplate should always be used when determining final compatibility.

---

36. Cabinet Installation

The approximately 521 × 511 × 416 mm physical dimensions should be considered carefully when designing the cabinet.

A 667 A drive is a substantial electrical component.

The cabinet must provide adequate space for:

• Drive mounting.
• Incoming AC conductors.
• Motor armature conductors.
• Field wiring.
• Control wiring.
• Feedback wiring.
• Protective equipment.
• Disconnects.
• Ventilation.
• Maintenance access.

The approximate 61 kg drive weight also needs to be considered when designing the mechanical support structure.

---

37. Thermal Management

Thermal management is particularly important for a drive of this power level.

The drive and other cabinet components generate heat during normal operation.

The cabinet designer should calculate the complete heat load.

Cooling can involve natural convection, forced-air ventilation, heat exchangers, or other methods depending on the cabinet and operating environment.

The drive should not be installed in a cabinet merely because there is sufficient physical space.

There must also be adequate thermal capacity.

---

38. Power Wiring

A 667 A drive requires substantial power conductors.

The incoming AC conductors and motor armature conductors must be sized according to the applicable electrical requirements and installation conditions.

The exact conductor size depends on factors such as:

• Installation method.
• Ambient temperature.
• Cable insulation rating.
• Cable length.
• Conductor grouping.
• Voltage drop.
• Applicable electrical standards.

Protective devices and disconnect equipment must also be appropriately selected.

---

39. Feedback Wiring

If the machine uses encoder or tachometer feedback, the feedback cables should be installed carefully.

Feedback signals are relatively low-level compared with the high-current motor circuit.

Good cable routing and grounding practices can help minimize electrical interference.

Feedback wiring should be kept away from high-current conductors where practical.

Correct shielding and termination should be maintained according to the feedback-device requirements.

---

40. PLC and Automation Integration

The 20P41AD667RA0NNN can be integrated into a larger industrial automation system.

Typical control functions can include:

• Start.
• Stop.
• Enable.
• Speed reference.
• Direction command.
• Fault reset.
• Drive status.
• Alarm status.
• Current monitoring.
• Speed feedback.
• External interlocks.

The drive can therefore operate as the motor-control component within a larger PLC-based machine.

---

41. Winding System Example

Consider a large steel-strip winding system.

The winding roll may weigh several tons.

At startup, the drive must provide sufficient torque to accelerate the roll.

As the roll rotates, the motor must maintain the required process speed.

As material accumulates, the roll diameter changes.

The control system may adjust the motor speed and torque reference accordingly.

When the machine stops, the roll must decelerate under controlled conditions.

The regenerative capability of the 20P41AD667RA0NNN becomes particularly useful during this part of the operating cycle.

---

42. Unwinding System Example

In a large unwinding machine, material is pulled from a roll by downstream equipment.

The roll tends to rotate as the material is pulled away.

The motor can therefore be required to provide braking torque.

Under certain operating conditions, the motor enters a regenerative state.

The four-quadrant drive can manage this operating condition while maintaining the desired process behavior.

---

43. Large Conveyor Example

A high-capacity conveyor can contain substantial mechanical mass.

During startup, the motor must accelerate both the conveyor system and the material being transported.

A controlled acceleration profile reduces mechanical shock.

During stopping, the stored kinetic energy must be managed.

If the conveyor is heavily loaded or downhill, regenerative operation can become particularly important.

The 667 A rating gives the drive sufficient capacity for large motor systems within its specified operating range.

---

44. Large Processing Line Example

A continuous production line may contain several mechanical sections that need coordinated operation.

One section may feed material.

Another may process it.

Another may wind or rewind the finished product.

The motor speed of each section can affect the overall production process.

The drive’s speed-control and feedback capabilities can therefore be integrated into a larger coordinated control system.

---

45. High-Inertia Machinery

The larger the rotating mass, the more important controlled braking becomes.

A 400 HP motor can drive a machine with substantial inertia.

If the machine needs to stop quickly, the drive must manage the energy generated by the decelerating motor.

Regenerative operation provides a controlled method of handling this condition.

This is one of the major reasons why a regenerative DC drive is useful in high-inertia machinery.

---

46. Maintenance Considerations

High-power DC drive systems require attention to both the drive and the motor.

The drive cabinet should be inspected regularly for:

• Dust accumulation.
• Blocked airflow.
• Loose electrical connections.
• Signs of overheating.
• Abnormal odors.
• Contamination.
• Damaged wiring.
• Feedback problems.

The DC motor should also be inspected.

Important motor-maintenance items include:

• Brushes.
• Commutator.
• Bearings.
• Cooling.
• Field windings.
• Armature insulation.
• Mechanical coupling.

The condition of the motor can have a direct effect on the operating behavior of the drive.

---

47. DC Motor Retrofit Applications

The 20P41AD667RA0NNN can be relevant to facilities that still have large DC motors in service.

A DC drive retrofit can sometimes allow the existing motor and mechanical system to remain in operation.

This can reduce the mechanical changes associated with a complete motor conversion.

However, a retrofit should include a review of the existing motor.

The motor’s insulation, brushes, commutator, bearings, field circuit, armature circuit, feedback device, and mechanical coupling should all be inspected.

---

48. Selection Position Within the PowerFlex DC Family

The 20P41AD667RA0NNN occupies the 400 HP / 667 A position in the 460/480 V regenerative PowerFlex DC family.

A simplified progression is:

Model	Current	Motor Rating	Motor Power	Frame
20P41AD250RA0NNN	250 A	150 HP	112 kW	B
20P41AD330RA0NNN	330 A	200 HP	149 kW	B
20P41AD412RA0NNN	412 A	250 HP	187 kW	B
20P41AD495RA0NNN	495 A	300 HP	224 kW	C
20P41AD667RA0NNN	667 A	400 HP	298 kW	C
20P41AD830RA0NNN	830 A	500 HP	373 kW	D
20P41AD996RA0NNN	996 A	600 HP	447 kW	D
20P41AD1K1RA0NNN	1162 A	700 HP	552 kW	D

The PowerFlex DC technical selection data shows the progression from 250 A through 667 A and into the larger Frame D models.

---

49. Detailed Product Specification Table

Specification Category	20P41AD667RA0NNN
Brand	Allen-Bradley
Product Series	PowerFlex DC
Product Type	Digital Regenerative DC Drive
Catalog Number	20P41AD667RA0NNN
Input Voltage	480 VAC class
Input Phase	3-phase
Input Type	6-pulse
Output Current	667 A
Normal-Duty Motor Rating	400 HP
Motor Power	Approximately 298 kW
Motor Operation	Four-quadrant regenerative
Frame Size	C
Field Supply	Single-phase regulated
Enclosure Rating	IP20
Enclosure Type	NEMA/UL Type Open
Conformal Coating	Yes
HIM	Blank plate / no HIM
Communication Module	None in stated configuration
Feedback	DC tachometer / encoder capability
Digital I/O	Up to 12 digital inputs/outputs
Analog Inputs	Up to 3
Analog Outputs	Up to 4
Approx. Height	521 mm
Approx. Width	511 mm
Approx. Depth	416 mm
Approx. Dimensions	521 × 511 × 416 mm
Approx. Drive Weight	61 kg
Approx. Packaged Weight	83 kg
Installation	Cabinet / protected enclosure
Motor Type	DC motor
Application Class	High-power industrial
Braking	Regenerative
Speed Feedback	Encoder / DC tachometer
Main Use	High-power DC motor control

---

50. Main Advantages at a Glance

Feature	Practical Benefit
667 A output	Suitable for very large DC motors
400 HP rating	Supports high-power industrial machinery
298 kW class	Appropriate for substantial mechanical loads
Four-quadrant operation	Supports motoring and regeneration in both directions
Regenerative braking	Useful for high-inertia and cyclic machinery
480 VAC input	Suitable for industrial three-phase power
6-pulse architecture	Established industrial DC power-conversion structure
Frame C	High-current mechanical platform
IP20 construction	Suitable for protected cabinet installation
Conformal coating	Additional protection for electronics
Regulated field supply	Supports DC motor field control
Encoder/tachometer feedback	Suitable for precision speed control
Extensive I/O	Flexible machine integration
PowerFlex DC platform	Broad range of compatible DC drive ratings

---

51. Product Description for Industrial Catalogs

The Allen-Bradley 20P41AD667RA0NNN PowerFlex DC Drive is a high-power regenerative DC drive rated at 667 A and 400 HP / approximately 298 kW.

The unit is designed for 480 VAC, three-phase input and uses a 6-pulse input configuration with four-quadrant regenerative operation.

The drive is constructed in a Frame C mechanical configuration and uses an IP20 / NEMA/UL Type Open enclosure with conformal coating.

The standard catalog configuration includes a blank HIM plate, user manual, and no communication module.

With its high current capacity, regenerative braking capability, regulated field supply, feedback capability, and extensive I/O, the 20P41AD667RA0NNN is designed for demanding industrial DC motor applications.

Typical applications include large winding and unwinding machines, metal-processing equipment, paper machinery, printing and converting systems, high-capacity conveyors, heavy material-handling systems, high-inertia machinery, and large industrial production lines.

---

52. Product Selection Checklist

Before selecting the 20P41AD667RA0NNN for a machine, the following information should be reviewed.

Selection Item	Information to Confirm
Existing Drive	Existing catalog number
Motor Type	DC motor
Motor HP	Approximately 400 HP class
Motor kW	Approximately 298 kW
Armature Voltage	Motor nameplate value
Armature Current	Motor nameplate value
Field Voltage	Motor field requirement
Field Current	Motor field requirement
Rated Speed	Motor nameplate
Maximum Speed	Machine requirement
Feedback	Encoder / tachometer / other
Acceleration	Required acceleration time
Deceleration	Required deceleration time
Regeneration	Required operating function
Reversing	Required operating function
Load Inertia	Mechanical system characteristic
Incoming Supply	480 VAC three-phase class
Cabinet	Available mounting space
Cooling	Required thermal capacity
PLC Interface	Existing control architecture
Safety System	Machine-specific requirements

---

53. Overall Product Position

The 20P41AD667RA0NNN is a high-current member of the PowerFlex DC regenerative drive family.

Its 667 A current capacity and 400 HP / 298 kW motor rating place it in the high-power section of the 480 V DC-drive range.

The combination of high current capacity and four-quadrant regenerative operation makes it suitable for machinery that needs more than simple speed control.

It can provide controlled acceleration, controlled deceleration, reversing, and regenerative operation while supporting feedback-based speed regulation.

The Frame C mechanical construction provides an approximate physical envelope of 521 × 511 × 416 mm, with an approximate drive weight of 61 kg.

For installations using a large existing DC motor, this combination of electrical capacity, regenerative operation, field control, feedback capability, and industrial I/O makes the drive particularly relevant to large production machinery.

---

54. Final Technical Summary

The Allen-Bradley 20P41AD667RA0NNN belongs to the PowerFlex DC series and is a 667 A, 400 HP / approximately 298 kW regenerative DC drive intended for large industrial DC motor applications.

Its primary electrical characteristics include a 480 VAC three-phase input, 6-pulse input architecture, 667 A DC output rating, and four-quadrant regenerative motor operation.

The drive uses a single-phase regulated field supply, allowing the field circuit of the DC motor to be incorporated into the overall drive-control system.

The product uses Frame C construction, with approximate dimensions of 521 × 511 × 416 mm and an approximate drive weight of 61 kg.

Its IP20 / NEMA/UL Type Open enclosure makes it appropriate for installation inside a suitable industrial cabinet.

The conformal-coated configuration provides additional protection for the electronic assemblies, while the embedded encoder and DC tachometer feedback capability supports applications requiring controlled speed regulation.

The extensive I/O architecture also makes the drive suitable for integration into PLC-based industrial automation systems.

For large winding machines, unwinding systems, paper machinery, metal-processing equipment, large conveyors, heavy material-handling systems, high-inertia machinery, and other demanding DC motor applications, the 20P41AD667RA0NNN provides the electrical capacity required for motors in the 400 HP class.

Within the same PowerFlex DC family, the 20P41AD495RA0NNN is the closely related lower-current 300 HP model, while the 20P41AD830RA0NNN, 20P41AD996RA0NNN, and larger models extend the available current and motor-power range.

For a machine that already uses a large DC motor, the same-series models are the most directly relevant comparison products.

For new machine designs using AC motors, other PowerFlex families such as PowerFlex 525 and PowerFlex 755 can be considered separately, but they should not be treated as simple catalog-number replacements for a regenerative DC drive.

In practical terms, the 20P41AD667RA0NNN can be described as a high-power 667 A, 400 HP, four-quadrant regenerative PowerFlex DC drive designed for demanding industrial DC motor control applications, with the electrical capacity and control features required for large, high-inertia, reversing, winding, unwinding, and continuous-process machinery.