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20G1F4C585LNDNNNNN – PowerFlex 755 AFE Regenerative AC Drive

1. Product Overview

The 20G1F4C585LNDNNNNN is a high-power AC drive from the PowerFlex 755 series, designed for demanding industrial motor-control applications.

This model is a 400 VAC, three-phase, AFE regenerative drive configuration with a 644 A current rating and a Frame 8C construction. The AFE configuration is particularly useful in applications where regenerative energy needs to be returned to the electrical supply rather than simply dissipated as heat.

The drive is intended for large industrial motors and high-power machinery. Typical applications include large conveyors, cranes and hoists, test stands, material-handling systems, pumps, fans, process machinery, compressors, and other equipment where controlled acceleration, deceleration, speed regulation, and regenerative operation are required.

Compared with a conventional non-regenerative drive, the AFE arrangement is especially useful for applications that frequently decelerate high-inertia loads. During braking, energy generated by the motor can be transferred back toward the incoming AC system, depending on the complete system design and operating conditions.

The large-frame construction makes this product more suitable for dedicated electrical rooms, industrial drive lineups, and floor-mounted installations than for compact machine-mounted applications.

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2. Basic Product Information

Parameter	Specification
Brand	Allen-Bradley
Product Series	PowerFlex 755
Product Type	High-Power AC Drive
Model	20G1F4C585LNDNNNNN
Drive Configuration	AFE Regenerative
Input Voltage	400 VAC
Input Phase	Three Phase
Current Rating	644 A
Frame	Frame 8C
Cooling	Air-cooled / forced-air
Mounting	Large-frame industrial installation
Application	High-power industrial motor control
Motor Type	Three-phase AC motors
Regenerative Function	Active Front End regeneration
Control	Variable-frequency motor control
Installation Environment	Industrial electrical room / drive cabinet area
Typical Application	High-inertia and high-power machinery

The complete catalog number should be retained when specifying, purchasing, or replacing this drive because the individual catalog-number characters identify important configuration characteristics.

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3. Main Technical Parameters

Parameter	Specification
Model	20G1F4C585LNDNNNNN
Series	PowerFlex 755
Input Voltage	400 VAC
Input Phase	3 Phase
Input Type	AFE Regenerative
Current Rating	644 A
Frame Size	Frame 8C
Drive Type	Regenerative AC Variable Frequency Drive
Cooling	Forced-air cooled
Motor Control	Adjustable-frequency AC motor control
Application Class	High-power industrial
Regenerative Operation	Yes
Installation	Industrial floor-mounted / cabinet installation
Enclosure / Packaging	Configuration dependent
Communication	Configuration dependent
Feedback	Configuration dependent
Motor Power Class	Large industrial motor class
Dimensions	Configuration dependent; large Frame 8C cabinet
Weight	Configuration dependent; large-frame cabinet
Typical Use	Conveyors, cranes, hoists, process machinery, pumps, fans, compressors
Service Requirement	Adequate front access and ventilation required

The 644 A current value and 400 VAC rating are important distinguishing characteristics of this specific catalog number.

The Frame 8C designation indicates that this is a physically large, high-power drive configuration. The exact overall cabinet dimensions and shipping weight can vary with the selected cabinet arrangement and installed options, so the final mechanical drawing should be used for foundation and installation work.

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4. Electrical Characteristics

The 20G1F4C585LNDNNNNN operates on a 400 VAC three-phase industrial power system.

Its 644 A current rating places it in the high-capacity range of the PowerFlex 755 family.

The most important characteristic of this model is its AFE regenerative input configuration.

An Active Front End is designed to provide controlled power exchange between the AC supply and the drive DC bus. During motoring operation, electrical energy is supplied to the motor. During suitable regenerative conditions, energy produced by the motor can flow back through the active front end toward the AC supply.

This makes the configuration particularly relevant to machinery with frequent braking or four-quadrant operating requirements.

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5. AFE Regenerative Operation

Traditional variable-frequency drives generally use a diode or controlled rectifier input stage. When the motor becomes regenerative, excess energy is normally transferred to a braking resistor or another energy-handling system.

An AFE regenerative drive takes a different approach.

The active front end can control the power flow between the drive and the AC network. When the motor is decelerating and returning energy, the regenerative energy can be transferred back to the electrical system.

This can be particularly useful for:

• High-inertia conveyors
• Cranes
• Hoists
• Elevators
• Test equipment
• Unwind / rewind machinery
• Centrifuges
• Large rotating equipment
• Downhill conveyors
• Repetitive acceleration/deceleration machinery

The practical benefit depends on the operating cycle. A machine that rarely regenerates will not obtain the same benefit as a machine that repeatedly converts mechanical energy back into electrical energy.

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6. Product Introduction

The 20G1F4C585LNDNNNNN is intended for applications where a conventional low-power drive is not sufficient and where regenerative operation is an important part of the system design.

Its 644 A rating provides substantial current capacity for large AC motors.

The Frame 8C construction also reflects the high-power nature of the equipment. This is not a compact wall-mounted drive intended for small machinery. It is better suited to a dedicated industrial electrical installation where there is sufficient floor space, ventilation, cable access, and maintenance clearance.

The drive can be integrated into a larger motor-control system together with upstream electrical equipment, control systems, communication networks, and motor feedback equipment.

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7. High-Power Drive Construction

Large-frame drives require a different installation approach from small variable-frequency drives.

The installation should provide adequate space for:

• Incoming power connections
• Motor output cables
• Control wiring
• Communication cables
• Cooling airflow
• Front service access
• Inspection
• Maintenance
• Lifting and transportation
• Heat dissipation

Because the drive operates at a high current level, cable selection and termination quality are particularly important.

The electrical system should also be designed with appropriate grounding, protection, disconnect equipment, and short-circuit considerations.

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8. Dimensions and Weight

The exact dimensions and weight of the 20G1F4C585LNDNNNNN should be taken from the mechanical drawing for the specific supplied configuration.

Mechanical Parameter	Specification
Frame	Frame 8C
Installation	Large industrial cabinet / floor installation
Height	Configuration dependent
Width	Configuration dependent
Depth	Configuration dependent
Weight	Configuration dependent
Cooling	Forced-air
Service Clearance	Required
Cable Access	Configuration dependent
Lifting Requirement	Required for large cabinet installation

For engineering planning, this model should be treated as a large high-power cabinet assembly, rather than a small standalone VFD.

The final dimensions and shipping weight can change depending on the exact cabinet construction, power components, options, input/output equipment, and other factory-selected configurations.

For that reason, an installation should not be designed around an assumed single cabinet dimension or weight.

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9. Cooling and Thermal Management

At a current rating of 644 A, thermal management is an important part of system design.

The drive uses forced-air cooling to move heat away from the power electronics.

The electrical room should provide sufficient airflow and heat-removal capacity.

Particular attention should be paid to:

• Air intake
• Exhaust airflow
• Cooling fans
• Cabinet ventilation
• Ambient temperature
• Airborne dust
• Filter condition
• Recirculation of hot air
• Room HVAC capacity

If the drive is installed in a high-dust environment, the cooling system should be inspected regularly.

Restricted airflow can increase internal temperatures and may reduce the operating margin of power electronic components.

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10. Main Product Features

Feature	Description
High Current Capacity	644 A class for large industrial motors
400 VAC Input	Designed for 400 V-class three-phase systems
AFE Regeneration	Supports controlled regenerative power flow
Frame 8C	Large-frame construction for high-power applications
Variable-Speed Control	Allows motor speed to be adjusted according to process requirements
High-Power Operation	Suitable for large industrial machinery
Industrial Control	Designed for integration with automation systems
Diagnostic Capability	Provides operating and fault information
Feedback Compatibility	Can support feedback-based control configurations
High-Inertia Capability	Particularly useful for demanding acceleration/deceleration cycles
Floor-Mounted Installation	Suitable for centralized electrical installations
Modular Architecture	Supports application-specific options and control arrangements

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11. Product Applications

11.1 Large Conveyors

Large conveyors can generate considerable mechanical energy during deceleration.

In a conventional system, that energy may need to be dissipated through braking equipment.

A regenerative drive can instead return suitable regenerative energy to the AC system.

This can be valuable in:

• Mining conveyors
• Bulk-material conveyors
• Cement plants
• Aggregate handling
• Port equipment
• Long-distance conveyors
• Inclined conveyors

The advantage becomes particularly relevant when a conveyor repeatedly accelerates, decelerates, or operates with substantial load inertia.

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11.2 Cranes and Hoists

Cranes and hoists are typical applications for regenerative drives.

When a heavy load is lowered, the motor can operate in a generating mode.

The energy produced during lowering can be transferred through the regenerative drive system instead of being handled solely through resistive braking.

Potential applications include:

• Overhead cranes
• Gantry cranes
• Container-handling equipment
• Industrial hoists
• Lifting systems
• Steel mill cranes
• Port machinery

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11.3 Test Stands

Motor test systems can frequently accelerate and decelerate equipment.

A regenerative drive can be useful where the test cycle repeatedly changes motor speed and operating direction.

Typical applications include:

• Motor test benches
• Gearbox test systems
• Mechanical test stands
• Generator testing
• Industrial equipment testing
• High-inertia test machinery

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11.4 Centrifuges

Centrifuges can store significant kinetic energy at high rotational speed.

When the centrifuge decelerates, a large amount of mechanical energy can be returned to the drive.

A regenerative configuration can therefore be useful where the machine performs repeated high-speed acceleration and deceleration cycles.

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11.5 Unwind and Rewind Machinery

Web-handling equipment can operate in motoring and generating conditions depending on the direction of material movement and tension requirements.

A regenerative drive can provide controlled energy management while maintaining accurate motor speed and torque.

Applications include:

• Steel processing
• Paper processing
• Film production
• Cable manufacturing
• Textile machinery
• Web handling

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12. Additional Applications

Application	Typical Requirement
Large Conveyor	High torque and controlled braking
Mining Conveyor	High power and regenerative operation
Crane	Four-quadrant operation
Hoist	Controlled lowering and lifting
Centrifuge	High-speed acceleration and regeneration
Test Stand	Repeated acceleration/deceleration
Elevator	Regenerative braking
Rewind Machine	Torque and speed control
Unwind Machine	Controlled tension
Large Fan	Variable-speed operation
Large Pump	Adjustable flow and pressure
Compressor	Controlled speed and process output
Process Machinery	Speed and torque regulation

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13. Main Advantages

13.1 Regenerative Energy Recovery

The primary advantage of this configuration is its regenerative capability.

When a motor is driven mechanically by the load, it can operate as a generator.

Instead of relying entirely on braking resistors to dissipate this energy, the AFE system can transfer suitable regenerative energy back toward the AC supply.

This can be particularly valuable in machinery with frequent braking cycles.

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13.2 Suitable for High-Inertia Loads

High-inertia machinery can require substantial energy during acceleration and can return substantial energy during deceleration.

The regenerative architecture is well suited to this operating pattern.

Examples include:

• Large flywheels
• Heavy conveyors
• Centrifuges
• Hoists
• Cranes
• Large rotating machinery

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13.3 Controlled Acceleration and Deceleration

The drive can control the motor’s acceleration and deceleration profile.

This allows engineers to establish controlled ramp times rather than relying on abrupt starting or stopping.

Controlled acceleration can help reduce mechanical shock.

Controlled deceleration can also improve machine behavior during stopping operations.

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13.4 Large Motor Capacity

The 644 A current rating provides substantial capacity for high-power industrial motors.

This makes the model suitable for applications where smaller PowerFlex drive configurations cannot provide sufficient output current.

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13.5 Reduced Dependence on Braking Resistors

For applications with significant regeneration, a conventional braking resistor can become large and can generate considerable heat.

A regenerative drive provides an alternative energy-handling method.

This can be especially useful when braking occurs frequently.

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13.6 Industrial Automation Integration

The PowerFlex 755 architecture is designed for integration with industrial control systems.

Depending on the selected communication and control configuration, the drive can exchange operating commands, speed references, status information, alarms, and diagnostic data with higher-level control equipment.

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14. Energy Management Advantages

The energy behavior of the machine should be considered when evaluating this model.

A regenerative drive does not automatically reduce energy consumption in every application.

Its strongest advantage appears when the machine repeatedly produces regenerative energy.

For example, a large conveyor that frequently decelerates can return energy during braking.

A crane can generate energy when lowering a heavy load.

A centrifuge can return energy while slowing down from high speed.

These operating conditions are fundamentally different from a simple constant-speed fan that rarely regenerates.

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15. Comparison With a Conventional AC Drive

Feature	Conventional Drive	20G1F4C585LNDNNNNN
Variable Speed	Yes	Yes
Motor Control	Yes	Yes
High-Power Operation	Application dependent	Yes
Regenerative Operation	Usually requires additional equipment	Integrated AFE configuration
Braking Energy	Often dissipated	Can be returned to AC system
High-Inertia Applications	Suitable with correct braking design	Particularly suitable
Four-Quadrant Applications	Additional equipment may be required	Suitable configuration
Large Industrial Motors	Yes	Yes
Automation Integration	Available	Available
Current Rating	Model dependent	644 A

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16. Installation Advantages

The large-frame configuration is suitable for centralized electrical installations.

Instead of installing a small drive directly on a machine, this type of equipment can be located in a dedicated drive room or electrical cabinet lineup.

This arrangement can provide easier access to:

• Power connections
• Control wiring
• Communication networks
• Maintenance components
• Cooling equipment
• Protective devices
• Drive diagnostics

It also allows large drive systems to be organized systematically within a plant electrical distribution structure.

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17. Maintenance Advantages

The drive provides diagnostic information that can assist maintenance personnel in identifying abnormal operating conditions.

Important maintenance information can include:

• Drive status
• Output current
• Motor speed
• Output frequency
• Fault history
• Warning conditions
• Temperature-related information
• Communication status
• Operating conditions

For large industrial equipment, reviewing drive diagnostics can help maintenance teams identify problems before they develop into major production interruptions.

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18. Maintenance Recommendations

Maintenance Area	Recommended Inspection
Cooling Fans	Check operation and unusual noise
Airflow	Ensure unrestricted ventilation
Cabinet Interior	Keep clean and dry
Power Terminals	Inspect for heat or looseness
Motor Cables	Check insulation and connections
Grounding	Verify grounding integrity
Control Wiring	Check terminals and connectors
Communication	Verify network operation
Fault History	Review repeated faults
Temperature	Monitor abnormal thermal conditions
Mechanical Components	Check cabinet fans and related components
Regenerative System	Monitor abnormal DC-bus or line conditions

Maintenance frequency should be adjusted according to the operating environment.

A clean electrical room and a dusty industrial production area should not necessarily use the same maintenance interval.

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19. Motor Selection

Selecting a motor for the 20G1F4C585LNDNNNNN should be based on more than horsepower.

The following information should be checked:

Motor Parameter	Importance
Rated Voltage	Must match the drive application
Full-Load Current	Critical for drive sizing
Rated Power	Determines motor power class
Rated Frequency	Required for correct control
Rated Speed	Important for operating range
Starting Torque	Important for acceleration
Maximum Speed	Important for mechanical safety
Minimum Speed	Important for motor cooling
Load Inertia	Important for acceleration/deceleration
Duty Cycle	Important for thermal sizing
Regenerative Duty	Important for AFE selection
Motor Insulation	Important for VFD operation
Cable Length	Important for electrical design

For regenerative applications, the load profile is particularly important.

The engineering team should understand not only how much power the motor consumes, but also how much energy it returns during deceleration.

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20. Application Selection Guide

Application Type	Suitability of 20G1F4C585LNDNNNNN
Large Conveyor	Very suitable
Inclined Conveyor	Very suitable
Mining Conveyor	Very suitable
Crane	Very suitable
Hoist	Very suitable
Centrifuge	Very suitable
Test Stand	Very suitable
Elevator	Suitable
Rewind Machine	Suitable
Unwind Machine	Suitable
Large Pump	Suitable
Large Fan	Suitable
Compressor	Application dependent
Mixer	Application dependent
Simple Constant-Speed Motor	May not require regenerative architecture

The strongest application case is generally a large motor system where speed control and regenerative energy handling are both important.

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21. Same-Series and Related Models

The following models are useful comparison choices within the PowerFlex 755 family.

Model	Series	Voltage Class	Current Class	Configuration	Typical Application	Dimensions	Weight
20G1F4C540LNDNNNNN	PowerFlex 755	400 VAC	540 A class	Regenerative / large-frame configuration	Large conveyors, pumps, process machinery	Large-frame cabinet	Configuration dependent
20G1F4C585LNANNNNN	PowerFlex 755	400 VAC	585 A class	Standard input configuration	Large pumps, fans, conveyors	Large-frame cabinet	Configuration dependent
20G1F4C650LNDNNNNN	PowerFlex 755	400 VAC	650 A class	Regenerative configuration	Large industrial machinery	Large-frame cabinet	Configuration dependent
20G1F4C750LNDNNNNN	PowerFlex 755	400 VAC	750 A class	Regenerative configuration	Large motors and process equipment	Large-frame cabinet	Configuration dependent
20G1F4C920LNDNNNNN	PowerFlex 755	400 VAC	920 A class	Regenerative configuration	Very large industrial motors	Large-frame cabinet	Configuration dependent

These models are closely related from a product-family perspective.

The most important differences are current capacity and configuration.

When selecting a substitute, the input topology should be checked carefully. A standard-input drive and an AFE regenerative drive are not automatically interchangeable simply because their current ratings are similar.

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22. Five Related Model References

Model	Main Specification	Current Class	Voltage	Configuration	Dimensions	Weight
20G1F4C540LNDNNNNN	PowerFlex 755 high-power AC drive	540 A	400 VAC	LND configuration	Configuration dependent	Configuration dependent
20G1F4C585LNANNNNN	PowerFlex 755 high-power AC drive	585 A class	400 VAC	Standard configuration	Configuration dependent	Configuration dependent
20G1F4C650LNDNNNNN	PowerFlex 755 high-power AC drive	650 A	400 VAC	Regenerative configuration	Configuration dependent	Configuration dependent
20G1F4C750LNDNNNNN	PowerFlex 755 high-power AC drive	750 A	400 VAC	Regenerative configuration	Configuration dependent	Configuration dependent
20G1F4C770LNDNNNNN	PowerFlex 755 high-power AC drive	770 A	400 VAC	Regenerative configuration	Configuration dependent	Configuration dependent

The 540 A model is useful when the required motor current is below the 644 A capacity of the subject model.

The 650 A, 750 A, and 770 A versions provide progressively greater current capacity and may be considered for motors with higher full-load current or more demanding operating conditions.

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23. Five Popular Same-Brand Model References

Model	Series / Product Type	Main Specification	Typical Application	Dimensions	Weight
20G1F4C540LNANNNNN	PowerFlex 755 AC Drive	400 VAC, 540 A class	Pumps, fans, conveyors	Large-frame cabinet	Configuration dependent
20G1F4C585LNANNNNN	PowerFlex 755 AC Drive	400 VAC, 585 A class	Large industrial motors	Large-frame cabinet	Configuration dependent
20G1F4C650LNANNNNN	PowerFlex 755 AC Drive	400 VAC, 650 A class	Large process equipment	Large-frame cabinet	Configuration dependent
20G1F4C750LNANNNNN	PowerFlex 755 AC Drive	400 VAC, 750 A class	High-power machinery	Large-frame cabinet	Configuration dependent
20G1F4C920LNANNNNN	PowerFlex 755 AC Drive	400 VAC, 920 A class	Very large motor systems	Large-frame cabinet	Configuration dependent

These models provide a useful range for comparing high-power motor-control requirements within the same product family.

For an actual replacement project, however, the comparison should include the full catalog number, input configuration, enclosure arrangement, current rating, braking/regeneration method, control options, communication modules, and mechanical construction.

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24. Difference Between LNANNNNN and LNDNNNNN Configurations

The configuration suffix is important.

The subject model is:

20G1F4C585LNDNNNNN

while a closely related model is:

20G1F4C585LNANNNNN

Although the model numbers look very similar, the configurations should not be treated as identical.

The LND configuration is associated with the AFE regenerative version for this model.

This distinction matters because the input power stage, regeneration behavior, system design, and application requirements can be different.

For replacement work, the original catalog number should therefore be matched as closely as possible rather than selecting a model based only on the 585 A rating.

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25. Advantages for Heavy-Duty Industrial Systems

The 20G1F4C585LNDNNNNN can provide several practical benefits in heavy industrial applications.

First, its high current capacity allows it to control large motors without moving immediately into an even larger drive frame.

Second, the AFE architecture provides an effective method for managing regenerative energy.

Third, the PowerFlex 755 platform provides advanced control and diagnostic capabilities suitable for integration into automated industrial systems.

Fourth, its large-frame construction is appropriate for centralized electrical installations where serviceability and system organization are important.

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26. Engineering Considerations

When specifying this drive, engineers should evaluate the entire system rather than looking only at the drive current.

Important design questions include:

• What is the motor full-load current?
• What is the motor rated voltage?
• How much regenerative energy is produced?
• How frequently does regeneration occur?
• What is the load inertia?
• How quickly must the motor accelerate?
• How quickly must it decelerate?
• Is four-quadrant operation required?
• What is the available incoming voltage?
• What is the transformer capacity?
• What is the available short-circuit current?
• What cable size is required?
• What cooling capacity is available?
• What communication network will be used?
• What environmental conditions will the drive experience?

These factors determine whether the drive is properly matched to the machine.

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27. Recommended Installation Environment

The preferred installation environment is a controlled industrial electrical area.

The following conditions should be considered:

Condition	Recommendation
Ambient Temperature	Within the applicable drive operating range
Humidity	Controlled and non-condensing
Dust	Minimized
Water Exposure	Avoid direct exposure
Ventilation	Adequate
Heat Removal	Adequate for drive losses
Vibration	Controlled
Electrical Noise	Proper grounding and cable practices
Maintenance Access	Adequate
Floor Loading	Suitable for large cabinet weight

The physical installation should also account for transportation into the building.

Because the equipment is a large-frame assembly, door width, elevator capacity, floor loading, lifting points, and final positioning should be considered during project planning.

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28. Technical Benefits at a Glance

Benefit	Explanation
High Current	644 A capacity for large motors
Regeneration	Suitable for returning regenerative energy to the AC system
400 VAC	Fits common 400 V industrial systems
Large Frame	Designed for high-power applications
Advanced Control	Provides controlled speed and torque
High-Inertia Capability	Well suited to demanding acceleration/deceleration cycles
Industrial Integration	Suitable for PLC/DCS/SCADA-based systems
Diagnostics	Supports troubleshooting and maintenance
Flexible Applications	Suitable for many large motor applications
Centralized Installation	Suitable for electrical rooms and drive lineups

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29. Final Technical Specification Table

Category	Specification
Model	20G1F4C585LNDNNNNN
Brand	Allen-Bradley
Series	PowerFlex 755
Product Type	High-Power AFE Regenerative AC Drive
Input Type	AFE Regenerative
Input Voltage	400 VAC
Phase	Three Phase
Current	644 A
Frame	Frame 8C
Cooling	Forced-Air
Mounting	Large-frame industrial installation
Motor Control	Variable-frequency AC motor control
Regenerative Operation	Yes
Feedback	Configuration dependent
Communication	Configuration dependent
Enclosure	Configuration dependent
Typical Application	Conveyors, cranes, hoists, centrifuges, pumps, fans, process machinery
Height	Configuration dependent
Width	Configuration dependent
Depth	Configuration dependent
Weight	Configuration dependent
Service Access	Required
Installation	Industrial electrical room / drive cabinet area

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30. Final Product Description

The 20G1F4C585LNDNNNNN is a high-power PowerFlex 755 AC drive configured with an Active Front End regenerative input stage.

With a 400 VAC three-phase input, 644 A current rating, and Frame 8C construction, it is intended for large industrial motor systems where conventional low-power variable-frequency drives are not sufficient.

The most distinctive feature of this model is its regenerative capability.

For applications such as cranes, hoists, large conveyors, centrifuges, test stands, elevators, and other high-inertia machinery, the motor can frequently operate in generating mode during deceleration. The AFE system provides a means of transferring suitable regenerative energy back toward the AC supply.

This makes the model particularly relevant to machinery with repeated acceleration and deceleration cycles.

The large-frame design also makes the drive suitable for centralized industrial electrical installations. Adequate floor space, cooling, cable access, maintenance clearance, and electrical infrastructure should be included during the design stage.

From an application standpoint, the model is most valuable when three requirements occur together: high motor power, precise variable-speed control, and significant regenerative operation.

For a replacement or new installation, the complete catalog number should always be checked because small changes in the catalog number can represent meaningful differences in input topology, enclosure arrangement, current rating, options, and control configuration.

Overall, the 20G1F4C585LNDNNNNN is a high-capacity industrial drive intended for large AC motors and demanding applications where regenerative energy management is an important part of the machine’s operating cycle.