Product Overview

The Schneider Electric ATS48C25Y Altistart 48 Soft Starter is an industrial motor starting and stopping device designed for three-phase asynchronous motors. Part of the Altistart 48 product family, it provides controlled acceleration and deceleration to help reduce the electrical and mechanical stress associated with direct-on-line motor starting.

When a large motor starts directly across the supply, it can draw a high starting current and produce sudden mechanical torque. These conditions may affect the power distribution system, motor components, couplings, belts, pumps, and other connected machinery. A soft starter controls the voltage applied to the motor during startup, allowing the motor to accelerate more gradually.

The ATS48C25Y has a rated operating current of 240 A and supports motor supply voltages from 208 to 690 V AC. It is designed for industrial applications involving pumps, compressors, conveyors, fans, and other motor-driven equipment. Its Altistart 48 control technology includes torque-control functions, motor thermal protection, and configurable starting and stopping parameters.

The device also provides communication through a Modbus serial interface using an RS-485 physical connection. This allows it to exchange operating information with compatible PLCs and industrial automation systems.

The ATS48C25Y is designed for installation in the motor supply line. Its IP00 protection rating means it must be installed inside a suitable electrical enclosure that provides the necessary protection against environmental exposure and accidental contact.

Schneider Electric has discontinued this model and recommends the ATS480C25Y from the newer Altivar Soft Starter range as a replacement candidate. For existing installations, the original model remains relevant to industrial maintenance, spare-parts procurement, and equipment replacement projects.

Technical Specifications

Motor power capability varies with supply voltage and operating duty. Always use the manufacturer’s selection tables to determine the correct rating for a specific motor and application.

Function and Working Principle

The ATS48C25Y controls the voltage supplied to an asynchronous motor during starting and stopping. Its electronic power circuit uses controlled semiconductor switching to regulate motor acceleration and deceleration.

1. Controlled Motor Starting

During direct-on-line starting, a motor can draw several times its rated current. This sudden current demand may cause voltage drops in the electrical network and create additional stress on connected equipment.

The ATS48C25Y gradually increases the motor supply voltage according to the configured starting parameters. This allows the motor to accelerate more smoothly and helps manage starting current and mechanical torque.

The actual starting performance depends on motor characteristics, load inertia, current settings, and the selected starting profile.

2. Torque Control

The Altistart 48 series includes torque-control functions designed to provide controlled motor acceleration and deceleration.

Torque control is useful in applications where sudden changes in mechanical force can damage equipment or disturb the production process. For example, pump systems may experience pressure disturbances during abrupt starting or stopping, while conveyors may require controlled acceleration to prevent material movement problems.

The appropriate control settings depend on the motor and driven load.

3. Soft Stopping

The ATS48C25Y can control motor deceleration rather than simply removing power immediately.

This function is particularly useful in applications where abrupt stopping may cause hydraulic shock, mechanical vibration, or product displacement. A controlled stopping profile can help reduce these effects.

Soft stopping does not replace a mechanical braking system or a safety-rated stopping function where those are required by the machine design.

4. Motor Thermal Protection

Motor thermal protection helps monitor operating conditions and protect the motor against excessive thermal loading.

The starter also provides thermal protection for its own power components. Correct motor data and protection settings are important for reliable operation.

External protective devices may still be required depending on the installation, applicable electrical standards, and the machine’s safety design.

5. Communication and Monitoring

The ATS48C25Y supports Modbus serial communication through an RS-485 interface. Compatible control equipment can use this connection to exchange supported operating data and control information.

This can help integrate the soft starter into a PLC-based automation system, allowing operators and maintenance personnel to monitor motor operation and relevant status information.

Role in Industrial Automation Systems

The ATS48C25Y is commonly used as part of a motor-control circuit. It works alongside protective devices, contactors, PLCs, motors, and operator interfaces.

PLC Integration

A programmable logic controller can coordinate the soft starter with other machine components. Depending on the system design, the PLC may issue start and stop commands, monitor operating states, and respond to fault conditions.

The ATS48C25Y’s Modbus RS-485 interface provides an additional communication option for compatible PLC systems. Engineers should verify communication settings, register assignments, and network wiring before commissioning.

HMI Monitoring

An HMI can display motor operating status, alarms, and relevant process information. In a typical automation architecture, the HMI communicates with the PLC, which exchanges information with the soft starter.

This arrangement allows operators to supervise motor operation from a central interface rather than relying entirely on local electrical controls.

Motor Protection Coordination

The soft starter must be coordinated with the motor, upstream circuit protection, isolation devices, and any external bypass arrangement.

Correct coordination is important for preventing equipment damage and ensuring that faults can be detected and isolated appropriately.

Integration with Plant Control Systems

In larger industrial installations, multiple motor starters may be coordinated by a PLC or distributed control system. The ATS48C25Y can participate in such an arrangement through its available control inputs, outputs, and Modbus communication interface.

The communication and control design should be based on the actual hardware configuration and the requirements of the plant automation system.

Industrial Applications

The ATS48C25Y is designed for demanding industrial motor-starting applications. Its 240 A rating makes it relevant to larger motor installations, subject to the motor voltage, power, duty classification, and application requirements.

1. Industrial Pump Systems

Pumps are widely used in water treatment, chemical processing, cooling systems, and general manufacturing.

Sudden motor starting and stopping can create pressure changes in connected pipework. A soft starter can help manage acceleration and deceleration, reducing the mechanical disturbance associated with abrupt operation.

The ATS48C25Y’s torque-control and soft-stop functions are relevant to pump installations where controlled motor operation is required.

2. Industrial Compressors

Large compressors often require substantial starting current and torque. Controlled starting can help manage the electrical demand during motor acceleration.

The soft starter can be used in suitable compressor systems where the motor and mechanical arrangement are compatible with reduced-voltage starting.

Engineers should evaluate compressor unloading arrangements, starting torque, restart frequency, and motor thermal limits before selecting the starter.

3. Conveyor Systems

Conveyors transport materials through manufacturing, mining, packaging, and logistics facilities.

A controlled starting profile can help reduce sudden mechanical loading on belts, gearboxes, couplings, and conveyor structures. Soft stopping may also help reduce unwanted material movement.

For long or heavily loaded conveyors, the complete mechanical and electrical design must be assessed to ensure that the starter provides the required starting torque.

4. Industrial Fans and Blowers

Large ventilation fans and blowers are used in manufacturing plants, industrial buildings, and process facilities.

A soft starter can help manage motor acceleration and reduce sudden mechanical stress on fan assemblies. The starting profile should be selected according to fan inertia, motor characteristics, and operating conditions.

5. Water Treatment Facilities

Water treatment plants use pumps, mixers, blowers, and other motor-driven equipment. Controlled motor starting can help reduce electrical disturbances and improve the operation of equipment connected to process pipelines.

The ATS48C25Y may be considered for compatible motor installations where its electrical ratings and control functions meet the application requirements.

6. Heavy Industrial Machinery

Industrial production equipment may include large motors driving mixers, processing machinery, and material-handling systems.

The soft starter’s controlled acceleration and stopping functions can help manage mechanical loading during normal machine operation. Application suitability must be confirmed through motor and load calculations.

Installation and System Integration

Correct installation is essential for reliable soft-starter operation, effective cooling, and electrical safety.

1. Verify Supply Voltage and Motor Ratings

The ATS48C25Y supports motor supply voltages from 208 to 690 V AC. Before installation, confirm the incoming supply voltage, phase configuration, frequency, motor nameplate current, and motor power.

The 240 A rated operating current should be considered alongside the actual application duty. Motor power alone is not sufficient for selecting a soft starter.

2. Select the Correct Enclosure

The ATS48C25Y has an IP00 protection rating. It must be installed inside a suitable electrical enclosure that protects against accidental contact and environmental contamination.

The enclosure should provide sufficient space for wiring, inspection, ventilation, and maintenance access.

3. Provide Adequate Cooling

The unit uses forced-convection cooling. Proper airflow is essential to prevent excessive internal temperature during operation.

Keep ventilation openings unobstructed and follow the manufacturer’s clearance requirements. The cabinet design must account for heat generated by the starter and other installed electrical equipment.

4. Connect Power and Motor Wiring

The soft starter is designed for connection in the motor supply line.

Power conductors, motor cables, control wiring, and protective grounding must be installed according to the manufacturer’s documentation and applicable electrical regulations.

Use appropriately rated cables and upstream protective devices. Isolate the electrical supply and follow lockout procedures before installation or maintenance.

5. Configure Starting and Stopping Parameters

Configure the starting current, acceleration profile, stopping method, and relevant motor-protection parameters according to the application.

Settings that are too restrictive may prevent the motor from accelerating properly. Excessively aggressive settings may increase electrical or mechanical stress.

Commissioning should include testing under representative operating conditions.

6. Configure Modbus Communication

When the soft starter is integrated into a PLC network, configure the Modbus communication parameters according to the control-system design.

Check the RS-485 wiring, communication speed, addressing, and data format. The communication connection should be tested before the system is returned to normal operation.

7. Commission and Test the Installation

After wiring and configuration, verify the motor’s direction of rotation, starting performance, stopping behavior, fault response, and communication status.

Record the final parameter settings and wiring arrangement. This documentation helps maintenance personnel troubleshoot the installation and restore the correct configuration after equipment replacement.

Compatible System Components

The ATS48C25Y is normally installed as part of a complete motor-control system. The following components may be used alongside it, depending on the application design.

The components listed above are examples of a complete installation. They are not necessarily supplied with the ATS48C25Y.

Alternative Models and Replacement Considerations

The ATS48C25Y has been discontinued. Schneider Electric identifies the ATS480C25Y from the Altivar Soft Starter range as its recommended replacement candidate.

Before selecting a replacement, compare the following parameters:

• Rated operating current and motor power.
• Supply voltage and frequency.
• Normal-duty and heavy-duty operating requirements.
• Starting torque and acceleration time.
• Soft-stop requirements.
• Control circuit voltage.
• Digital and relay I/O arrangements.
• Modbus communication settings and interface.
• Enclosure dimensions and cooling requirements.
• Wiring, mounting, and protection coordination.

Although the ATS480C25Y is the manufacturer’s recommended replacement, it should not automatically be treated as a plug-and-play substitute. Differences in terminals, communication configuration, parameters, and installation requirements may require engineering changes and recommissioning.

Key Advantages

Controlled Motor Acceleration

The ATS48C25Y provides controlled motor starting, helping manage starting current and mechanical torque in suitable applications.

Soft-Stop Functionality

Its controlled stopping capability can help reduce mechanical disturbance in applications where abrupt motor stopping is undesirable.

Torque-Control Technology

The Altistart 48 series supports torque-control functions that can be configured according to motor and load requirements.

Integrated Thermal Protection

Motor and starter thermal protection functions help monitor operating conditions and reduce the risk of damage from excessive thermal loading.

Modbus Communication

The RS-485 Modbus interface allows the soft starter to exchange supported information with compatible PLCs and industrial control systems.

Industrial Current Rating

With a 240 A rated operating current, the ATS48C25Y is intended for larger industrial motor applications when correctly matched to the supply voltage and duty requirements.

Established Industrial Installation Base

The Altistart 48 series has been used in industrial motor-control systems. Its established installation base makes accurate identification and spare-parts sourcing important for maintenance operations.

Technical FAQs

1. What is the Schneider Electric ATS48C25Y?

The ATS48C25Y is an Altistart 48 soft starter designed for controlled starting and stopping of three-phase asynchronous motors.

2. What is the rated current of the ATS48C25Y?

Its rated operating current is 240 A. The motor selection must also account for supply voltage, motor power, and operating duty.

3. What voltage range does this soft starter support?

The ATS48C25Y supports motor supply voltages from 208 to 690 V AC.

4. What is the control supply voltage?

The control circuit voltage range is 110–230 V AC. Confirm the actual control supply requirements before wiring the unit.

5. Does the ATS48C25Y support Modbus?

Yes. It supports Modbus serial communication through an RS-485 physical interface, using an RJ45 connector.

6. Does it provide motor thermal protection?

Yes. The Altistart 48 provides motor and starter thermal protection functions. Correct configuration and coordination with other protective devices remain necessary.

7. What is the protection rating?

The ATS48C25Y has an IP00 rating. It must be installed inside a suitable electrical enclosure.

8. What are the dimensions and weight?

The published dimensions are 380 × 320 × 265 mm, and the product weight is 18.2 kg.

9. Is the ATS48C25Y still available as a current production model?

No. Schneider Electric lists the ATS48C25Y as discontinued, with standard service scheduled to end on December 31, 2030. Availability through spare-parts suppliers may vary.

10. What is the recommended replacement?

Schneider Electric recommends the ATS480C25Y as the replacement candidate. Before changing models, verify the motor ratings, control functions, communication requirements, wiring, and installation dimensions.

Procurement and Maintenance Recommendations

When purchasing the ATS48C25Y, verify the complete model number and inspect the product nameplate. Confirm that the rated current, operating voltage, control supply, and communication requirements match the original installation.

For used or refurbished equipment, request clear photographs of the product label, terminals, front panel, and cooling components. Ask for available testing information and clarify whether the unit is supplied with any accessories.

Because the model is discontinued, buyers should also consider the availability of replacement parts and long-term maintenance requirements. If the soft starter is used in a critical production process, evaluate whether a transition to the ATS480C25Y is appropriate.

During routine maintenance, inspect electrical connections, grounding, ventilation paths, and the condition of the enclosure. Keep the cooling system unobstructed and check for signs of overheating or abnormal operation.

Back up the parameter settings and document the PLC communication configuration. This information can reduce commissioning time if the original unit needs to be replaced.

Conclusion

The Schneider Electric ATS48C25Y Altistart 48 Soft Starter is an industrial motor starting and stopping controller with a 240 A rated operating current and a 208–690 V AC operating voltage range. Its torque-control functions, soft-start and soft-stop capabilities, integrated thermal protection, and Modbus RS-485 communication make it suitable for a range of industrial asynchronous motor applications.

Although the ATS48C25Y has been discontinued, it remains relevant to existing industrial installations and maintenance projects. Accurate model verification, electrical compatibility checks, and careful replacement planning are essential when sourcing or replacing this soft starter. Schneider Electric recommends the ATS480C25Y as the successor candidate, subject to application-specific engineering verification.