ACS355-03E-31A0-4 Variable Frequency Drive 15kW 31A 400V

The ACS355-03E-31A0-4 is a 15 kW variable frequency drive designed for speed and torque control of compatible three-phase motors in industrial machinery.

It operates from a three-phase 380–480 V AC supply and provides a rated output current of 31 A. This combination supports selected 15 kW or 20 hp motors when the motor current, application load and operating duty remain within the drive ratings.

The 31A0 model uses the larger R4 frame. This distinguishes it from the lower-power 23A1 model, which provides 23.1 A in an R3 frame. The R4 construction also accommodates the 38A0 and 44A0 versions, but those models have different current and power ratings.

Scalar and sensorless vector control support general variable-speed operation and applications requiring improved speed or torque performance. The drive can control compatible AC induction and permanent-magnet motors when the correct motor data and parameters are entered.

Built-in RS-485 communication supports Modbus RTU. Optional adapters can be added when the machine requires another industrial network.

Key Differentiating Features

• Exact ACS355-03E-31A0-4 configuration
• Product identification number 3AUA0000058193
• 15 kW or 20 hp rated motor power
• 31 A rated output current
• 21 kVA apparent output power
• Three-phase 380–480 V AC input
• R4 frame construction
• IP20 open-type enclosure
• Sensorless vector and scalar motor control
• Support for selected induction and permanent-magnet motors
• Built-in RS-485 Modbus RTU
• Integrated Safe Torque Off input
• Eight-step sequence programming
• Integrated brake chopper
• Two analog inputs
• Five digital inputs
• Cabinet-mounted module construction
• Approximately 5.4 kg net weight
• Base ordering code supplied without a control panel

Understanding the Model Code

The complete ACS355-03E-31A0-4 designation identifies the electrical configuration of the drive.

The 03E code does not indicate an IP55 enclosure. The protection rating of this specific product is IP20.

The full model code should be compared with the existing nameplate before purchasing a replacement.

Rated Power and Output Current

This model is rated for 15 kW under normal-use conditions with a continuous output current of 31 A.

The wider product family contains multiple power ratings, but its complete range must not be entered as the power rating of this individual drive.

Drive sizing must consider:

• Motor nameplate current
• Continuous motor torque
• Starting torque
• Acceleration time
• Deceleration time
• Repeated overload demand
• Operating speed
• Braking energy
• Switching frequency
• Ambient temperature
• Installation altitude
• Motor-cable length

A 15 kW motor should not be connected solely because its power rating matches. The motor current and application duty must also be compatible.

Three-Phase 380–480 V Supply

The ACS355-03E-31A0-4 requires a three-phase 380–480 V AC input supply.

It is not the correct version for standard single-phase input or a 200–240 V system. Confirm the incoming electrical supply before installation.

Check:

• Supply voltage
• Number of phases
• Supply frequency
• Upstream circuit protection
• Cable conductor size
• Protective grounding
• Isolation arrangement
• Short-circuit capacity
• Applicable electrical regulations

The drive output is intended for a compatible three-phase motor. The motor cable and drive output should not be switched during normal operation unless the machine design specifically permits it.

Scalar and Sensorless Vector Control

Scalar control provides frequency-based motor control for general machinery where basic speed regulation is sufficient.

Sensorless vector control can provide improved speed and torque response without requiring a motor encoder in compatible applications.

Possible control functions include:

• Variable-speed operation
• Forward and reverse rotation
• Controlled acceleration
• Controlled deceleration
• Multiple preset speeds
• Torque limitation
• Process reference control
• Motor protection monitoring
• Mechanical brake sequencing

Correct motor nameplate data is required for reliable vector-control performance.

Motor Compatibility

The drive supports compatible AC induction and permanent-magnet motors.

Before commissioning, verify:

• Motor type
• Rated motor voltage
• Rated motor current
• Rated motor frequency
• Rated motor speed
• Rated motor power
• Required control mode
• Motor thermal protection
• Maximum operating frequency

Permanent-magnet motor operation requires the correct motor data and a compatible drive configuration. Matching only the power rating does not establish compatibility.

Integrated Inputs and Outputs

The standard hardware provides configurable control terminals for machine integration.

Available resources include:

• Two analog inputs
• One analog output
• Five digital inputs
• One digital output
• One relay output
• RS-485 communication
• Safe Torque Off connections

The old page’s specification of three digital inputs and one analog input is incorrect.

Digital inputs can be configured for start, stop, direction, preset speed selection, fault reset and other machine-control functions.

Analog inputs can accept compatible speed, torque or process-reference signals. Wiring and parameter assignments must be checked before transferring connections from an existing drive.

Modbus RTU Communication

RS-485 Modbus RTU communication is available as a standard feature.

It can exchange:

• Start and stop commands
• Speed references
• Drive status
• Output frequency
• Output current
• Fault information
• Selected process values

Confirm the device address, baud rate, parity, stop bits, register mapping, termination and communication timeout before connecting the drive to an existing network.

PROFIBUS, CANopen, DeviceNet, EtherNet/IP and PROFINET require compatible optional adapters. These network interfaces are not all integrated into the base drive.

Safe Torque Off

Safe Torque Off is built into the drive. It is not an optional safety module as stated on the old page.

When correctly activated, the function prevents the drive from producing motor torque. It does not disconnect the incoming mains supply or electrically isolate the power terminals.

The complete safety circuit must be designed and validated according to the machine risk assessment. Separate electrical isolation is required before installation or maintenance.

Sequence Programming

The drive supports eight-step sequence programming for simple repetitive machine operations.

A sequence can use settings such as:

• Speed reference
• Running direction
• Acceleration time
• Deceleration time
• State duration
• Digital output status
• Transition conditions

This feature can reduce external logic requirements for uncomplicated standalone machinery. More complex coordinated systems should use an appropriate PLC or motion controller.

Braking and Deceleration

The integrated brake chopper supports connection of a compatible external braking resistor when regenerative energy must be dissipated during deceleration.

A resistor may be required for:

• High-inertia loads
• Rapid stopping
• Repeated start-stop cycles
• Vertical movement
• Winding machinery
• Centrifuges
• Loaded conveyors

The resistor must be selected according to resistance, power, energy and duty-cycle requirements. It is not included automatically with the base drive.

Model Comparison

The 31A0 version is the first 380–480 V model in this comparison to use the R4 frame.

Changing from an R3 model to the R4 version may require modifications to the mounting space, power cables, protective devices and cabinet cooling.

Dimensions and Cabinet Installation

The R4 drive has the following listed dimensions:

Because the enclosure is IP20 open type, install it inside a suitable industrial electrical cabinet.

The cabinet must provide:

• Environmental protection
• Adequate cooling airflow
• Required installation clearances
• Protective grounding
• Separation of power and signal wiring
• Electromagnetic compatibility
• Suitable cable-bending space
• Maintenance access

Do not block the cooling openings or install the drive directly above equipment that produces excessive heat.

Control Panel and Accessories

The base ACS355-03E-31A0-4 ordering code is normally supplied without a control panel.

Confirm the complete ordering code and package contents before purchasing. A suffix added to the base model may identify a control panel or another configured option.

Possible accessories include:

• Basic control panel
• Assistant control panel
• Remote panel mounting kit
• Fieldbus adapter
• External braking resistor
• Input or output choke
• EMC accessories
• PC commissioning connection
• Cabinet cooling equipment

The selected accessory must be compatible with the exact drive model and machine configuration.

Typical Applications

• Industrial conveyor systems
• Material-handling equipment
• Packaging machinery
• Mixers and agitators
• Extruder auxiliary drives
• Printing machinery
• Textile equipment
• Rubber-processing machinery
• Plastic-processing equipment
• Woodworking machines
• Process pumps
• Industrial fans
• Winding and unwinding equipment
• Replacement of an existing ACS355-03E-31A0-4
• Industrial control-panel maintenance

Actual suitability depends on the motor, load profile, braking requirements and environmental conditions.

Replacement Checklist

Before ordering, confirm:

• Complete model ACS355-03E-31A0-4
• Product ID 3AUA0000058193
• Three-phase 380–480 V supply
• 15 kW power requirement
• 31 A rated output current
• R4 frame dimensions
• Existing motor nameplate
• Power and motor cable sizes
• Upstream protective devices
• Control-terminal assignments
• Modbus communication settings
• Braking-resistor configuration
• Optional communication adapter
• Control-panel requirement
• Existing parameter backup

After installation, verify the motor direction, current limits, control source, acceleration and deceleration times, safety circuit and communication settings before returning the machine to production.

Frequently Asked Questions

1. What is the rated power of ACS355-03E-31A0-4?

Its rated output power under normal-use conditions is 15 kW or 20 hp.

2. What is the rated output current?

The rated output current is 31 A.

3. What input voltage does it require?

It requires a three-phase 380–480 V AC supply.

4. What frame size does it use?

It uses the R4 frame.

5. Does 03E indicate IP55 protection?

No. The 03 code identifies three-phase input, while E identifies the IEC configuration with the EMC filter connected. This model has an IP20 enclosure.

6. What are the correct dimensions?

The listed dimensions are 244 × 169 × 260 mm.

7. What is the product net weight?

The listed net weight is approximately 5.4 kg.

8. Does it include Modbus communication?

Yes. RS-485 Modbus RTU is available as a standard feature.

9. Are Ethernet and PROFIBUS built in?

No. These networks require compatible optional communication adapters.

10. How many analog inputs are provided?

The standard drive has two analog inputs and one analog output.

11. How many digital inputs are available?

Five digital inputs are provided.

12. Is Safe Torque Off optional?

No. Safe Torque Off functionality is built into the drive. The complete machine safety system must still be designed and validated correctly.

13. Does it support sensorless vector control?

Yes. It supports sensorless vector control and scalar control.

14. Is a braking resistor included?

No. The integrated brake chopper can operate with a compatible external resistor selected separately.

15. Is a control panel included?

The base ordering code is normally supplied without a control panel. Check the complete option code and supplied package.

16. Can it directly replace ACS355-03E-23A1-4?

Not automatically. The two models use different frames and current ratings. Wiring, protection, mounting space, motor data and parameters must be checked.