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Allen-Bradley 20P21AF565RA0NNN PowerFlex 565 A DC Drive

1. Product Overview

The Allen-Bradley 20P21AF565RA0NNN is a high-power PowerFlex DC Drive designed for demanding industrial motor-control applications requiring stable, adjustable-speed DC motor operation at a high power level.

This model is rated for a 690 VAC three-phase supply class and provides a 565 A DC output rating, corresponding to approximately 500 HP or 373 kW under the applicable normal-duty rating.

The 20P21AF565RA0NNN belongs to the PowerFlex Digital DC Drive family and is configured as a non-regenerative, two-quadrant DC drive. It is intended for applications where controlled acceleration, deceleration, speed regulation, torque control, and reliable DC motor operation are required.

The unit uses an IP20 enclosure with a NEMA/UL Type Open construction and conformal-coated circuitry. The conformal coating is particularly useful in industrial environments where additional protection of electronic components is desirable.

The catalog number is supplied without a Human Interface Module, using a blank plate configuration. It is also specified without a standard communication module, allowing the control architecture to be configured according to the requirements of the overall machine or plant system.

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2. Basic Product Information

Parameter	Specification
Brand	Allen-Bradley
Product Series	PowerFlex Digital DC Drive
Product Family	PowerFlex DC Drive
Model / Catalog Number	20P21AF565RA0NNN
Product Type	Digital DC Drive
Drive Rating	565 A
Normal-Duty Power	373 kW
Normal-Duty Horsepower	500 HP
AC Supply Class	690 VAC
Input Phase	Three-phase
Drive Type	Non-regenerative DC Drive
Motor Operation	Two-quadrant operation
Enclosure Rating	IP20
Enclosure Type	NEMA/UL Type Open
Circuit Board Protection	Conformal coated
Human Interface Module	No HIM / Blank Plate
Communication Module	None in standard configuration
Frame Size	C
Intended Motor Type	DC motor
Control Technology	Digital DC motor control
Application Class	Heavy industrial motor control
Installation Type	Industrial panel / cabinet installation

The 20P21AF565RA0NNN is part of the 690 V class PowerFlex DC range. Within this range, the 565 A model sits between the 452 A / 400 HP version and the 678 A / 600 HP version, making it a high-capacity option for large DC motor installations.

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3. Detailed Technical Specifications

3.1 Electrical Specifications

Parameter	20P21AF565RA0NNN Specification
Model	20P21AF565RA0NNN
Rated DC Output Current	565 A
Normal-Duty Output Power	373 kW
Normal-Duty Motor Rating	500 HP
AC Input Voltage Class	690 VAC
AC Input Phase	3 Phase
Input Frequency	50/60 Hz class industrial supply
Drive Architecture	Digital DC Drive
Regeneration	Non-regenerative
Quadrant Operation	Two Quadrant
Input Rectification	Six-pulse class
DC Motor Control	Yes
Speed Control	Yes
Current / Torque Regulation	Yes
Field Supply	Regulated field supply configuration
Communication Module	None supplied as standard
HIM	Blank plate / no HIM
Enclosure	IP20
Conformal Coating	Yes
Frame	Frame C

The 565 A rating is the key identifying electrical characteristic of this model. The corresponding 690 V-class selection table places the 20P21AF565RA0NNN at 373 kW and 500 HP, with a Frame C construction.

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3.2 Approximate Mechanical Specifications

Mechanical Parameter	Specification
Model	20P21AF565RA0NNN
Frame Size	C
Approx. Width	521 mm
Approx. Height	511 mm
Approx. Depth	416 mm
Approx. Product Weight	68 kg
Approx. Shipping Weight	85–95 kg
Mounting	Panel / cabinet mounting
Enclosure Type	IP20, NEMA/UL Type Open
Cooling	Forced-air cooling
Installation Environment	Industrial control cabinet
Service Clearance	Allow additional clearance for ventilation and maintenance
Mounting Orientation	Vertical cabinet mounting recommended

The dimensions and weight above should be treated as approximate Frame C values for planning purposes. Final cabinet design should always allow for terminal access, cable bending radius, ventilation, service access, and the exact mechanical arrangement of the installed unit.

Because this is a high-power 500 HP DC drive, mechanical installation is substantially different from compact low-power AC variable-frequency drives. The cabinet, ventilation system, power wiring, protective devices, and heat dissipation arrangement should all be designed around the actual installation.

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4. Product Model Number

The complete catalog number is:

20P21AF565RA0NNN

The catalog number identifies the PowerFlex DC product family, voltage class, current rating, enclosure/configuration characteristics, and factory configuration.

For product selection, the most important identifying portions are the AF voltage-class designation and the 565 current designation.

The 565 portion corresponds to the 565 A drive rating, while the associated PowerFlex DC selection table identifies this model as the 500 HP / 373 kW version in the 690 V class.

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5. Product Series

The 20P21AF565RA0NNN belongs to the:

Allen-Bradley PowerFlex Digital DC Drive Series

The PowerFlex DC family is designed specifically for industrial applications that use DC motors and require controlled speed, current, torque, acceleration, and deceleration.

Unlike compact AC frequency inverters intended to control induction or permanent-magnet AC motors, a DC drive directly manages the electrical characteristics required by a DC motor system.

This makes the PowerFlex DC family particularly relevant to industrial machinery that historically uses large DC motors, especially applications where high starting torque, stable low-speed operation, controlled acceleration, and precise speed regulation are important.

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6. Product Introduction

The Allen-Bradley 20P21AF565RA0NNN is a high-capacity industrial DC motor drive rated at 565 A and 500 HP.

It is designed for applications where a large DC motor must operate under controlled speed and torque conditions. Its digital control architecture allows the drive to regulate motor current and speed in response to operating commands and feedback signals.

The unit is particularly suitable for large production machinery where the motor may experience frequent load changes, high starting torque requirements, controlled acceleration, or extended periods of continuous operation.

The 690 VAC three-phase input class makes this model suitable for large industrial power systems. Its 565 A output rating places it in the upper-power range of the PowerFlex DC product family.

The IP20 open construction is intended for installation inside an appropriate industrial enclosure or control cabinet. This configuration gives system integrators flexibility when designing large electrical control panels, MCC sections, drive cabinets, and centralized automation systems.

The conformal-coated circuit boards provide additional protection for electronic components and can be beneficial in industrial environments where dust, humidity, contaminants, and other environmental factors require greater consideration.

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7. Main Product Functions

7.1 DC Motor Speed Control

The primary function of the 20P21AF565RA0NNN is controlled DC motor operation.

The drive can regulate motor speed according to the application command while maintaining controlled motor current and torque characteristics.

This makes it suitable for machines that require stable speed during changes in production load.

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7.2 Controlled Acceleration

The drive can provide controlled motor acceleration instead of applying the full available motor torque immediately.

Controlled acceleration helps reduce mechanical shock on couplings, gearboxes, rolls, shafts, belts, chains, and other transmission components.

This is particularly important for large industrial machines with significant rotating inertia.

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7.3 Controlled Deceleration

The drive also provides controlled deceleration for two-quadrant applications.

This can be useful when large machinery needs to slow down in a controlled manner rather than simply removing motor power.

Controlled deceleration can help improve machine operating consistency and reduce unnecessary mechanical stress.

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7.4 Current and Torque Regulation

DC motors are well suited to applications requiring high starting torque and controlled torque response.

The drive regulates motor current to support controlled motor operation and provide predictable torque characteristics.

This is particularly useful for applications where the load changes significantly during operation.

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7.5 Digital Control

The PowerFlex DC architecture provides digital control functions rather than relying on a simple analog-only drive arrangement.

Digital configuration allows important operating parameters to be managed in a structured manner and makes the drive suitable for integration into modern industrial automation systems.

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7.6 High-Power Industrial Operation

With a 565 A rating and 500 HP normal-duty rating, the 20P21AF565RA0NNN is intended for large machines rather than small motor applications.

It is suitable for heavy industrial equipment where the motor may operate continuously and where reliable speed and torque regulation are required.

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8. Typical Product Applications

8.1 Steel Processing Equipment

The 20P21AF565RA0NNN can be used in large steel-processing machinery where DC motors provide controlled speed and torque.

Potential applications include rolling equipment, material handling systems, processing lines, tension-control equipment, and other large mechanical systems.

The high current capability makes the drive suitable for large motors that require substantial starting torque.

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8.2 Paper and Pulp Machinery

Large paper machines have historically used DC motors because of their speed regulation and torque-control characteristics.

Typical applications can include large rolls, dryers, winders, unwinders, conveyors, and process sections.

A high-power DC drive can provide stable motor control across a wide operating range.

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8.3 Printing Machinery

Industrial printing equipment can require precise speed coordination between different machine sections.

A DC drive can be used where an existing DC motor system requires controlled speed and torque.

The 20P21AF565RA0NNN is particularly relevant to large industrial printing machinery rather than small commercial printing equipment.

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8.4 Mining Equipment

Large mining and mineral-processing equipment can require very high motor power and controlled acceleration.

Applications may include conveyors, hoists, crushers, processing equipment, and other large mechanical systems.

The high current rating of the 20P21AF565RA0NNN makes it suitable for large motor systems when the DC architecture is retained.

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8.5 Material Handling

Large material-handling systems may require high starting torque and smooth acceleration.

DC drives can be useful for heavy conveyor systems, large lifting mechanisms, and other equipment where the motor must start under significant load.

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8.6 Hoists and Lifting Equipment

Large lifting systems can benefit from controlled torque and speed regulation.

The drive can be integrated into an engineered control system where the motor, braking system, feedback devices, mechanical transmission, and safety circuits are designed as a complete system.

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8.7 Large Winder and Unwinder Systems

Winding machinery often requires controlled motor speed and torque.

Applications involving large reels, rolls, cables, paper, film, steel strip, wire, or similar continuous materials can require stable motor regulation throughout the winding cycle.

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8.8 Existing DC Motor Systems

One of the most practical applications for the 20P21AF565RA0NNN is modernization of an existing industrial DC motor installation.

Many large industrial machines were originally designed around DC motors. Replacing the complete motor system with an AC motor can require significant mechanical redesign.

Using a modern DC drive can allow the existing motor and mechanical transmission to remain in service while improving the control system.

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9. Main Product Advantages

9.1 High Current Capacity

The 565 A output rating provides substantial capacity for large DC motors.

This makes the model suitable for high-power machinery where smaller PowerFlex DC drives would not provide sufficient current capability.

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9.2 500 HP Industrial Rating

The 500 HP normal-duty rating places the 20P21AF565RA0NNN in the high-power industrial category.

It can therefore be considered for large production machines, heavy processing systems, and large mechanical drive applications.

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9.3 690 V Class

The 690 V three-phase input class allows the drive to be integrated into high-power industrial electrical systems.

Higher-voltage industrial power systems can be advantageous when supplying large loads because the current required on the AC side can be reduced compared with lower-voltage systems of similar power.

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9.4 Digital DC Control

Digital control provides a more flexible control platform than older analog DC drive technologies.

This is particularly useful when modernizing legacy industrial machinery.

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9.5 Conformal-Coated Electronics

The conformal-coated configuration provides additional protection for electronic circuit boards.

This can be useful for industrial environments where humidity, dust, and contaminants are important considerations.

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9.6 Two-Quadrant Operation

The two-quadrant configuration is suitable for many industrial applications that require controlled forward operation and controlled deceleration without requiring full four-quadrant regenerative operation.

For applications that require regenerative braking or reverse torque operation, a regenerative PowerFlex DC model should be considered instead.

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9.7 Open Industrial Construction

The IP20 NEMA/UL Type Open construction allows system integrators to install the drive within a larger electrical cabinet or control enclosure.

This is common for high-power industrial drive systems where ventilation, busbar systems, disconnects, fuses, contactors, control equipment, and other components are engineered as part of a complete cabinet.

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10. Five Related Models in the Same Series

The following models are closely related 690 V PowerFlex DC models. They are useful when comparing motor power and current requirements across the same product family.

Related Model	Voltage Class	Rated Current	Normal-Duty Power	Horsepower	Frame	Drive Type
20P21AF452RA0NNN	690 VAC, 3 Ph	452 A	298 kW	400 HP	C	Non-regenerative DC
20P21AF565RA0NNN	690 VAC, 3 Ph	565 A	373 kW	500 HP	C	Non-regenerative DC
20P21AF678RA0NNN	690 VAC, 3 Ph	678 A	447 kW	600 HP	D	Non-regenerative DC
20P21AF791RA0NNN	690 VAC, 3 Ph	791 A	552 kW	700 HP	D	Non-regenerative DC
20P21AF904RA0NNN	690 VAC, 3 Ph	904 A	597 kW	800 HP	D	Non-regenerative DC

The 20P21AF565RA0NNN is therefore positioned directly between the 400 HP and 600 HP versions in this 690 V PowerFlex DC range.

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11. Related Regenerative Models

For applications requiring regenerative operation, the corresponding 20P41AF family provides closely related high-power configurations.

Model	Voltage Class	Current	Power	Horsepower	Frame	Configuration
20P41AF452RA0NNN	690 VAC, 3 Ph	452 A	298 kW	400 HP	C	Regenerative DC
20P41AF565RA0NNN	690 VAC, 3 Ph	565 A	373 kW	500 HP	C	Regenerative DC
20P41AF678RA0NNN	690 VAC, 3 Ph	678 A	447 kW	600 HP	D	Regenerative DC
20P41AF791RA0NNN	690 VAC, 3 Ph	791 A	552 kW	700 HP	D	Regenerative DC
20P41AF904RA0NNN	690 VAC, 3 Ph	904 A	597 kW	800 HP	D	Regenerative DC

The main difference is the operating architecture. The 20P21AF565RA0NNN is a non-regenerative, two-quadrant configuration, while the corresponding 20P41AF565RA0NNN is intended for regenerative applications.

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12. Same-Series Model Comparison

Model	Current	Power	HP	Frame	Relative Application Range
20P21AF452RA0NNN	452 A	298 kW	400 HP	C	Large industrial machinery
20P21AF565RA0NNN	565 A	373 kW	500 HP	C	High-power industrial machinery
20P21AF678RA0NNN	678 A	447 kW	600 HP	D	Very high-power machinery
20P21AF791RA0NNN	791 A	552 kW	700 HP	D	Heavy industrial machinery
20P21AF904RA0NNN	904 A	597 kW	800 HP	D	Extremely high-power machinery

The selection should be based on the actual motor nameplate current, motor voltage, required duty cycle, ambient conditions, overload requirements, field requirements, and the complete electrical system design rather than horsepower alone.

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13. Five Popular Allen-Bradley Models for Comparison

The following five models are widely used PowerFlex AC drive configurations from the same Allen-Bradley brand. They are useful for comparison when the application is being considered for AC motor conversion or for new equipment.

They are not direct electrical replacements for the 20P21AF565RA0NNN. The 20P21AF565RA0NNN is a high-power DC drive, while the models below are PowerFlex 525 AC variable-frequency drives.

Model	Series	Input Voltage	Approx. Current	Motor Power	HP	Frame	Approx. Dimensions	Approx. Weight
25B-D2P3N104	PowerFlex 525	380–480 VAC, 3 Ph	2.3 A	0.75 kW	1 HP	A	72 × 152 × 172 mm	1.1 kg
25B-D6P0N104	PowerFlex 525	380–480 VAC, 3 Ph	6.0 A	2.2 kW	3 HP	A	72 × 152 × 172 mm	1.1 kg
25B-D010N104	PowerFlex 525	380–480 VAC, 3 Ph	10.5 A	4.0 kW	5 HP	B	87 × 180 × 172 mm	1.6 kg
25B-D017N104	PowerFlex 525	380–480 VAC, 3 Ph	17 A	7.5 kW	10 HP	C	109 × 220 × 184 mm	2.3 kg
25B-D024N114	PowerFlex 525	380–480 VAC, 3 Ph	24 A	11 kW	15 HP	D	130 × 260 × 212 mm	3.9 kg

These compact AC drives are intended for substantially smaller motor applications than the 500 HP 20P21AF565RA0NNN.

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14. Comparison Between the Main Product and PowerFlex 525 Models

Feature	20P21AF565RA0NNN	25B-D2P3N104	25B-D6P0N104	25B-D010N104	25B-D017N104	25B-D024N114
Drive Family	PowerFlex DC	PowerFlex 525	PowerFlex 525	PowerFlex 525	PowerFlex 525	PowerFlex 525
Motor Type	DC	AC	AC	AC	AC	AC
Input Class	690 VAC	380–480 VAC	380–480 VAC	380–480 VAC	380–480 VAC	380–480 VAC
Current	565 A	2.3 A	6.0 A	10.5 A	17 A	24 A
Power	373 kW	0.75 kW	2.2 kW	4 kW	7.5 kW	11 kW
HP	500 HP	1 HP	3 HP	5 HP	10 HP	15 HP
Regenerative	No	No	No	No	No	No
Main Application	Large DC motor	Small AC motor	Small AC motor	Small AC motor	Small AC motor	Small AC motor
Approx. Weight	68 kg	1.1 kg	1.1 kg	1.6 kg	2.3 kg	3.9 kg

This comparison illustrates the significant difference between the high-power DC drive and compact AC drives.

The 20P21AF565RA0NNN should therefore not be selected simply because another PowerFlex model has a similar control function. Motor type, voltage, current, feedback, field supply, braking requirements, and mechanical characteristics all need to be evaluated.

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15. Typical Industries

The 20P21AF565RA0NNN can be considered for a broad range of heavy industrial sectors, including:

Industry	Typical Equipment
Steel	Rolling mills, processing lines, conveyors, large drives
Metals	Strip processing, material handling, production machinery
Paper	Paper machines, rolls, winders, unwinders
Pulp	Process machinery, pumps, conveyors, large rotating equipment
Printing	Large industrial printing and web-handling machinery
Mining	Conveyors, hoists, processing equipment
Cement	Large material-handling and processing equipment
Material Handling	Heavy conveyors, lifting systems, transport equipment
Industrial Manufacturing	Large production machines
Cable Manufacturing	Large winders, pay-off systems, take-up equipment
Rubber Processing	Large mixers and processing machines
Plastics	Large legacy DC extrusion and processing equipment

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16. Application Advantages in Heavy Machinery

For heavy machinery, motor control is not only about turning the motor on and off.

Large mechanical systems contain significant inertia. A large roll, flywheel, conveyor, drum, gearbox, or production line can require substantial torque during starting and controlled torque during stopping.

A high-power DC drive provides a control platform capable of managing these operating conditions.

For example, when a large conveyor starts under load, the motor may require significant current immediately. A controlled drive can manage acceleration rather than exposing the mechanical system to an uncontrolled starting event.

In winding applications, speed and torque must remain coordinated as the diameter of the material roll changes. A properly engineered DC drive system can support this type of coordinated operation.

In steel processing, the motor may need to respond rapidly to load changes while maintaining a controlled production speed. The digital control architecture of the PowerFlex DC family is well suited to such industrial control requirements.

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17. Advantages for Existing DC Motor Installations

One of the strongest practical uses of a high-power DC drive is modernization of an existing DC motor installation.

A large DC motor may already be mechanically integrated into a production machine. The motor shaft, coupling, gearbox, bearings, mounting arrangement, cooling system, and production process may all have been designed around that motor.

Replacing the entire system with an AC motor can therefore become a major mechanical engineering project.

A DC drive modernization can potentially focus the upgrade on the electrical control system while preserving much of the existing mechanical infrastructure.

This can reduce mechanical modification requirements and make the modernization project more manageable.

The actual feasibility should always be confirmed by checking the motor nameplate, field requirements, feedback system, load profile, existing cabinet arrangement, protective devices, and available power supply.

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18. Installation Considerations

Because the 20P21AF565RA0NNN is a large 500 HP industrial drive, installation should be treated as a complete power-system engineering project.

The following factors should be considered:

• AC input voltage and transformer configuration.
• Available short-circuit current.
• Input protection.
• Semiconductor protection requirements.
• Motor armature voltage and current.
• Motor field voltage and current.
• Motor cooling arrangement.
• Encoder or tachometer feedback.
• Motor cable size.
• DC bus and armature wiring arrangement.
• Grounding and bonding.
• Cabinet ventilation.
• Heat dissipation.
• Ambient temperature.
• Altitude.
• Environmental contamination.
• Maintenance access.
• Control-system communication requirements.
• Emergency-stop architecture.
• Machine safety requirements.

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19. Cabinet and Ventilation Considerations

The IP20 open construction means the drive is normally incorporated into an appropriate industrial electrical enclosure rather than installed as a completely sealed standalone device.

At this power level, heat management is especially important.

The cabinet design should consider:

1. Drive heat dissipation.
2. Internal cabinet temperature.
3. Airflow direction.
4. Cooling fan arrangement.
5. Filter maintenance.
6. Ambient temperature.
7. Separation between power and control wiring.
8. Cable routing.
9. Service access.
10. Clearance around heat-generating components.

A large DC drive should not simply be placed inside a small sealed cabinet without performing a thermal calculation.

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20. Motor Compatibility

Before selecting the 20P21AF565RA0NNN, the motor nameplate should be checked carefully.

Important motor information includes:

Motor Parameter	Why It Matters
Motor Armature Voltage	Must be compatible with the drive configuration
Motor Armature Current	Must be within the drive’s current capability
Motor Horsepower	Used for drive sizing
Field Voltage	Required for correct field supply configuration
Field Current	Important for field controller sizing
Motor Speed	Required for control configuration
Base Speed	Important for speed regulation
Maximum Speed	Important for safe operation
Feedback Device	Encoder or DC tachometer compatibility
Duty Cycle	Determines thermal and overload requirements
Cooling Method	Affects continuous-duty capability
Mechanical Load	Determines acceleration and torque requirements

The 565 A drive rating should not be interpreted as meaning that every 500 HP DC motor is automatically compatible.

Motor voltage, field characteristics, speed range, feedback, duty cycle, and load requirements must all be checked.

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21. Maintenance Considerations

Large industrial DC drives require regular maintenance planning.

Typical maintenance activities can include inspection of cooling fans, cleaning of ventilation paths, inspection of power connections, checking of control wiring, examination of terminals, and verification of feedback devices.

Because high-current connections can carry substantial electrical energy, loose connections can generate heat and create reliability problems.

The cabinet environment should also be maintained carefully.

Dust accumulation can restrict airflow and increase internal temperatures.

Cooling fans should be inspected periodically.

The condition of the motor should also be considered as part of the drive maintenance program. A drive can only provide reliable control when the motor, feedback system, field system, power supply, and mechanical load are all operating correctly.

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22. Recommended Spare-Parts Strategy

For a critical production line, maintaining an appropriate spare-parts strategy can be important.

A high-power drive such as the 20P21AF565RA0NNN may be used in a production system where unexpected downtime can have significant consequences.

A practical spare-parts plan can include:

Spare / Service Item	Purpose
Main Drive Assembly	Rapid replacement
Cooling Fans	Restore thermal management
Control Components	Reduce troubleshooting time
Feedback Components	Maintain speed regulation
Fuses / Protection Components	Support power-system maintenance
Terminal Hardware	Service damaged or worn connections
Control Wiring	Restore control circuits
Documentation	Support troubleshooting and commissioning

The exact spare-parts list should be established according to the machine design and the installed configuration.

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23. Five Closely Related Models – Selection Guide

Model	Current	kW	HP	Frame	Suitable Position
20P21AF452RA0NNN	452 A	298 kW	400 HP	C	Lower-power alternative
20P21AF565RA0NNN	565 A	373 kW	500 HP	C	Main 500 HP configuration
20P21AF678RA0NNN	678 A	447 kW	600 HP	D	Higher-power configuration
20P21AF791RA0NNN	791 A	552 kW	700 HP	D	Higher-power configuration
20P21AF904RA0NNN	904 A	597 kW	800 HP	D	Very high-power configuration

The sequence shows how the PowerFlex DC family scales upward in current and motor power.

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24. Product Selection Notes

When evaluating the 20P21AF565RA0NNN, it is useful to separate five different sizing factors:

Motor Power

The motor is approximately 500 HP under the applicable normal-duty rating.

Motor Current

The 565 A rating is a critical selection parameter and should be compared against the actual motor armature current.

Motor Voltage

The motor armature voltage must be compatible with the selected DC drive and its field configuration.

Duty Cycle

A motor that runs continuously at high load may have different requirements from a motor that operates intermittently.

Regeneration

If the machine needs regenerative braking or sustained negative torque operation, a regenerative configuration should be evaluated rather than assuming that a non-regenerative drive is sufficient.

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25. Why the 20P21AF565RA0NNN Is Used in Large Industrial Systems

The main reason to select a drive of this size is not simply the horsepower number.

Large industrial machines often require:

• High starting torque.
• Controlled acceleration.
• Stable speed regulation.
• High continuous current capability.
• Reliable operation under varying loads.
• Integration with existing DC motors.
• Controlled deceleration.
• Industrial cabinet integration.
• Feedback-based speed regulation.
• Long-term maintainability.

The 20P21AF565RA0NNN is designed around these requirements.

Its 565 A capacity makes it substantially different from compact motor drives used in smaller machinery.

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26. Product Advantages Summary

Advantage	Description
High Current Capacity	565 A DC output capability
High Power	Approximately 373 kW / 500 HP
690 V Class	Suitable for large industrial electrical systems
Digital Control	Modern digital DC motor control architecture
Two-Quadrant Operation	Suitable for controlled motoring and deceleration applications
Conformal Coating	Additional protection for electronic circuitry
IP20 Construction	Designed for industrial cabinet integration
Frame C	High-power compact industrial frame within the family
DC Motor Compatibility	Suitable for large existing DC motor systems
Heavy-Duty Applications	Appropriate for large industrial machinery
Modernization Potential	Useful for upgrading legacy DC motor control systems

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27. Quick Technical Reference

Item	Specification
Brand	Allen-Bradley
Series	PowerFlex Digital DC Drive
Catalog Number	20P21AF565RA0NNN
Product	PowerFlex 565 A DC Drive
Input	690 VAC
Input Phase	3 Phase
Output Current	565 A
Normal-Duty Power	373 kW
Motor Rating	500 HP
Operation	Two Quadrant
Regeneration	Non-regenerative
Frame	C
Enclosure	IP20
Enclosure Type	NEMA/UL Type Open
Circuit Board	Conformal Coated
HIM	Blank Plate / No HIM
Communication Module	None Standard
Cooling	Forced Air
Approx. Dimensions	521 × 511 × 416 mm
Approx. Weight	68 kg
Motor Type	DC
Primary Application	High-power industrial DC motor control

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28. Five Same-Brand Popular Models – Quick Reference

Model	Series	Voltage	Current	Power	HP	Approx. Dimensions	Approx. Weight
25B-D2P3N104	PowerFlex 525	380–480 VAC	2.3 A	0.75 kW	1 HP	72 × 152 × 172 mm	1.1 kg
25B-D6P0N104	PowerFlex 525	380–480 VAC	6.0 A	2.2 kW	3 HP	72 × 152 × 172 mm	1.1 kg
25B-D010N104	PowerFlex 525	380–480 VAC	10.5 A	4.0 kW	5 HP	87 × 180 × 172 mm	1.6 kg
25B-D017N104	PowerFlex 525	380–480 VAC	17 A	7.5 kW	10 HP	109 × 220 × 184 mm	2.3 kg
25B-D024N114	PowerFlex 525	380–480 VAC	24 A	11 kW	15 HP	130 × 260 × 212 mm	3.9 kg

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29. Important Difference Between the Main Model and the Popular AC Models

The 20P21AF565RA0NNN is a high-power DC drive, while the 25B series models listed above are AC variable-frequency drives.

The two product categories should not be treated as direct substitutes.

The 20P21AF565RA0NNN is appropriate when the machine uses a DC motor and requires a high-current DC armature control system.

A PowerFlex 525 model is intended for AC motor applications and is normally selected according to AC motor voltage, current, horsepower, overload requirements, and control requirements.

For an existing 500 HP DC motor installation, replacing the drive with a small PowerFlex 525 would not be an equivalent substitution.

A complete motor and drive-system redesign would be required if converting from a large DC motor to an AC motor.

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30. Application Selection Summary

Application Requirement	Suitability of 20P21AF565RA0NNN
500 HP DC motor	Suitable application range
565 A DC motor current	Matching drive rating
Large industrial machinery	Suitable
Existing DC motor modernization	Suitable candidate
Controlled DC motor speed	Suitable
High starting torque	Suitable
Two-quadrant operation	Suitable
Regenerative braking requirement	Requires regenerative configuration evaluation
Small AC motor	Not the intended application
Compact machine	Generally oversized
New AC motor installation	AC drive family should be evaluated instead

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31. Overall Product Description

The Allen-Bradley 20P21AF565RA0NNN is a high-power PowerFlex Digital DC Drive rated at 565 A for 690 VAC three-phase industrial systems.

With a normal-duty rating of approximately 373 kW and 500 HP, it is intended for large DC motor applications where controlled speed, current, torque, acceleration, and deceleration are required.

Its Frame C construction, IP20 NEMA/UL Type Open enclosure, conformal-coated electronics, and high-current output make it suitable for integration into industrial control cabinets and large machine-control systems.

The model is particularly relevant to steel processing, paper and pulp machinery, printing equipment, mining equipment, large material-handling systems, heavy conveyors, winders, unwinders, and other industrial machinery that uses large DC motors.

For modernization projects, the 20P21AF565RA0NNN can be especially valuable where an existing DC motor and mechanical system remain serviceable but the original drive technology requires replacement or modernization.

The 565 A rating places the model between the 400 HP and 600 HP versions of the same 690 V PowerFlex DC family. The related 20P21AF452RA0NNN provides a lower 452 A / 400 HP configuration, while the 20P21AF678RA0NNN provides a higher 678 A / 600 HP configuration.

For applications requiring regenerative operation, the corresponding 20P41AF565RA0NNN configuration should be evaluated instead of treating the non-regenerative 20P21AF565RA0NNN as a regenerative drive.

Overall, the 20P21AF565RA0NNN is a specialized high-capacity industrial DC motor controller intended for large-scale machinery, heavy process equipment, and modernization of high-power DC motor systems.

For purchasing, replacement, or engineering purposes, the most important information to verify against the existing installation is the motor armature voltage, motor armature current, field voltage, field current, feedback device, motor speed, duty cycle, environmental conditions, braking requirements, and cabinet configuration.

The model should be selected as part of the complete motor-drive system rather than by horsepower alone.