Product Overview

The Schneider Electric ATS48M12Q Altistart 48 Soft Starter is a high-capacity motor starting and stopping device designed for large three-phase asynchronous motors. It belongs to the Altistart 48 product family and is intended for demanding industrial applications where controlled acceleration, torque management, and motor protection are important.

Unlike a conventional direct-on-line starter, which applies full supply voltage to the motor immediately, a soft starter gradually controls the voltage and torque during motor startup. This helps reduce electrical and mechanical stress associated with starting large motors. It can also provide controlled deceleration for applications where abrupt stopping may cause pressure fluctuations, mechanical shock, or process instability.

The ATS48M12Q supports a rated supply voltage range of 230–415 V AC and operates with 50/60 Hz power systems. Its product documentation identifies a factory-setting current of 1045 A. Motor power capability depends on the supply voltage, connection method, and application duty. At 400 V, the documented ratings include up to 630 kW for standard applications with line connection and up to 710 kW for severe applications with connection to the motor delta terminals.

The device uses torque-controlled starting and supports current limitation. Its functions are intended for large motors in heavy-duty industrial installations, pumping systems, ventilation equipment, and other applications where controlled motor acceleration is required.

The ATS48M12Q also provides motor and starter thermal protection, phase-failure monitoring, configurable logic inputs and outputs, relay status outputs, and Modbus serial communication through an RS485 interface.

The product has been discontinued, and Schneider Electric identifies the ATS480M12Y from the Altistart 480 range as a recommended replacement. Existing installations may continue to use the ATS48M12Q, but maintenance teams should verify its exact electrical configuration and plan replacement compatibility carefully.

Technical Specifications

Motor power ratings depend on supply voltage, line or delta connection, and standard-duty or severe-duty application conditions. Always use the manufacturer’s motor-starter selection tables for final sizing.

Function and Working Principle

The ATS48M12Q controls the voltage and torque supplied to a three-phase asynchronous motor during startup and stopping. Its primary purpose is to manage motor acceleration and deceleration while limiting the electrical and mechanical stresses associated with large motor operations.

1. Controlled Motor Starting

When a large motor starts directly across the supply, it can draw a high inrush current. This sudden current demand may affect the electrical distribution system and create mechanical stress in the driven equipment.

The ATS48M12Q gradually controls the motor-starting process. Instead of applying full voltage immediately, it regulates the starting conditions to achieve a smoother acceleration profile.

This is particularly important for large pumps, fans, compressors, and industrial machinery with substantial inertia or demanding starting conditions.

2. Torque Control

The Altistart 48 uses torque-controlled starting. This approach manages the motor’s torque response during acceleration rather than relying only on a simple voltage ramp.

Controlled torque can help reduce mechanical shock in equipment connected to the motor shaft. In pumping applications, for example, smoother acceleration can help reduce sudden pressure changes in the pipeline.

The actual starting performance depends on the motor characteristics, load torque, parameter settings, and application requirements.

3. Current Limitation

The ATS48M12Q supports adjustable starting-current limitation. Its product documentation identifies a starting-current limit of up to five times the rated current reference.

Current limitation is useful where the power supply has restrictions on starting current or where several large motors operate on the same electrical distribution network.

The current limit must be selected carefully. Setting it too low may prevent the motor from developing sufficient torque to accelerate the load, potentially resulting in extended starting time or a failed start.

4. Controlled Deceleration

The soft starter can also manage motor stopping. Controlled deceleration is useful when a machine must reduce speed gradually rather than stop abruptly.

For pump installations, controlled stopping can help reduce water hammer and pressure fluctuations. In material-handling systems, a more gradual stopping profile can reduce sudden mechanical movement.

The appropriate stopping method depends on the process and the motor-load characteristics.

5. Thermal Protection

The ATS48M12Q includes thermal protection functions for both the motor and the starter.

Motor thermal protection helps monitor conditions associated with motor heating and overload. Starter thermal protection helps protect the soft starter’s power components against excessive thermal stress.

These functions should be configured according to the motor’s nameplate information and operating conditions. They do not replace correctly selected upstream circuit protection or other required electrical safety devices.

6. Phase-Failure Monitoring

The device includes line phase-failure protection. This function helps identify abnormal supply conditions that could affect motor operation.

Phase-related faults can cause excessive motor heating, torque reduction, and abnormal current distribution. Monitoring these conditions is particularly important for large industrial motors.

Role in Industrial Control Systems

The ATS48M12Q is typically installed in a motor-control cabinet as part of a larger electrical and automation system. It provides controlled motor starting and stopping while interacting with upstream protection, PLC control logic, operator interfaces, and field equipment.

PLC Integration

A programmable logic controller can coordinate the soft starter with the rest of the production process.

The PLC may issue run and stop commands, monitor starter status, and respond to fault signals. For example, a water-treatment PLC can sequence several pumps according to tank level and pressure conditions.

The ATS48M12Q provides discrete control interfaces and Modbus serial communication over RS485. Engineers should select the appropriate interface according to the PLC hardware and system architecture.

HMI and Operator Monitoring

A human-machine interface can provide operators with information about motor status, startup progress, alarms, and operating conditions.

Through the PLC or a suitable Modbus connection, the HMI may display relevant starter information and allow authorized personnel to manage operating commands.

This arrangement helps operators monitor large motors without needing to access the motor-control cabinet directly.

Electrical Protection Coordination

A complete motor-control system requires suitable upstream circuit protection and isolation equipment. The soft starter manages motor starting, but it does not eliminate the need for properly coordinated protective devices.

Engineers should evaluate short-circuit protection, motor overload requirements, cable ratings, grounding, and the starter’s installation instructions when designing the electrical system.

Industrial Process Coordination

In a production facility, the ATS48M12Q can be used as part of a coordinated process sequence. A PLC may start a pump after checking valve positions, initiate a fan after confirming ventilation requirements, or stop equipment when a process interlock is activated.

The soft starter handles the controlled motor-starting function, while the PLC manages the broader automation sequence.

Industrial Applications

The ATS48M12Q is designed for large motor applications. Its high power ratings make it relevant to heavy industrial installations where motor startup, stopping, and protection require careful management.

1. Industrial Pumping Systems

Large pumps are commonly used in water treatment, wastewater processing, industrial cooling, and fluid-transfer installations.

When a pump starts or stops abruptly, pressure changes can affect pipelines, valves, and connected equipment. The ATS48M12Q can provide controlled motor acceleration and deceleration to help reduce these mechanical effects.

It is particularly relevant to pumping applications where the motor has a high power rating and the process requires a managed starting sequence.

2. Industrial Ventilation Systems

Large ventilation fans are used in factories, power stations, tunnels, and industrial processing facilities.

A high-capacity motor may create substantial starting current and mechanical stress when started directly. A soft starter can provide a more controlled acceleration process.

The ATS48M12Q can be integrated into ventilation control systems where the fan motor and electrical supply are compatible with its ratings.

3. Industrial Compressors

Large compressors are used in manufacturing plants, process facilities, and utility systems.

Compressor motors may experience demanding startup conditions depending on the compressor design and pressure state. A soft starter can help manage the electrical and mechanical conditions during startup.

The compressor manufacturer’s unloading and starting requirements must be considered when configuring the starter.

4. Water and Wastewater Treatment

Water treatment facilities often operate large pumps, blowers, and other motor-driven equipment.

The ATS48M12Q can be used in motor-control systems where controlled starting helps coordinate equipment operation with the treatment process.

PLC integration can support automatic pump sequencing, equipment interlocking, and fault monitoring.

5. Heavy Industrial Machinery

Large industrial machines may use high-power motors to drive mechanical equipment, conveyors, mixers, and process machinery.

Controlled starting can help reduce the mechanical shock associated with motor acceleration. The ATS48M12Q may be suitable where the motor’s electrical ratings and load requirements fall within the device’s documented application limits.

6. Power and Utility Infrastructure

Utility facilities often contain large pumps, ventilation equipment, and auxiliary motor-driven systems.

Soft starters can support controlled motor operation in these installations, particularly where starting-current management and mechanical protection are important.

The final selection should consider supply capacity, environmental conditions, operating duty, and the required protection architecture.

Installation and System Integration

The ATS48M12Q is a large, high-current motor-control device. Its installation requires appropriate electrical engineering, mechanical support, cooling arrangements, and commissioning procedures.

1. Verify Supply Voltage and Motor Ratings

The starter supports a rated supply voltage range of 230–415 V AC.

Before installation, verify:

• Incoming supply voltage and frequency.
• Motor rated voltage and current.
• Motor power and duty classification.
• Line or inside-delta connection method.
• Starting torque requirements.
• Expected starting frequency and operating cycle.

Do not select the starter based on motor kilowatt rating alone. The connection method and application duty have a direct effect on the applicable motor power rating.

2. Confirm Line and Delta Connection

The ATS48M12Q supports installation in the motor supply line or connection to the motor delta terminals, subject to the manufacturer’s wiring requirements.

These arrangements have different current and motor-power selection characteristics. The starter must be sized using the correct connection configuration.

Incorrect wiring can result in abnormal operation or damage to the motor and starter. Installation should be completed by qualified personnel using the applicable Schneider Electric diagrams.

3. Provide Suitable Cabinet and Mechanical Support

The supplied dimensions are 890 × 770 × 315 mm, and the listed weight is 115 kg.

Because of its size and weight, the device requires a suitable mounting structure and adequate mechanical support. The cabinet or installation frame must accommodate the equipment’s dimensions, cable connections, maintenance access, and ventilation requirements.

The specified IP00 protection degree means the starter requires an appropriate protective enclosure. It should not be installed where personnel can contact exposed live components.

4. Cooling and Ventilation

The ATS48M12Q uses forced-convection cooling. Its installation must provide sufficient airflow to remove heat generated during operation.

Maintain the clearances specified in the manufacturer’s documentation. Avoid obstructing air inlets and outlets, and consider the cabinet’s internal temperature when selecting ventilation equipment.

Operating temperature and derating requirements should be evaluated for installations exposed to elevated ambient temperatures.

5. Control Wiring and Communication

The starter provides discrete inputs, configurable logic outputs, relay outputs, and Modbus communication through an RS485 interface.

Control wiring should be routed and grounded according to the manufacturer’s recommendations. Communication wiring should be installed with suitable cable and termination practices for the RS485 network.

Before commissioning, verify the PLC communication settings, device address, baud rate, and control logic.

6. Configure Motor Protection

Enter the motor information and configure the starter’s protection and operating parameters according to the application.

Important considerations include:

• Motor rated current.
• Starting-current limitation.
• Starting torque requirements.
• Acceleration time.
• Deceleration settings.
• Motor thermal protection.
• Starter thermal protection.
• Phase-failure monitoring.

Incorrect settings can result in nuisance trips, excessive heating, or unsuccessful motor starts.

7. Commissioning and Functional Testing

Before energizing the system, inspect the power connections, control wiring, grounding, mechanical mounting, and ventilation arrangement.

During commissioning, verify the motor’s rotation direction, starting behavior, current profile, stopping behavior, fault indications, and PLC communication.

Record the final parameter configuration and retain it with the equipment maintenance documentation.

Compatible System Components

The ATS48M12Q is generally integrated with other electrical and automation components in a complete motor-control installation.

These components are examples of equipment used in a complete installation. They are not necessarily supplied with the ATS48M12Q.

Alternative Models and Replacement Considerations

The ATS48M12Q has been discontinued. Schneider Electric identifies the ATS480M12Y from the Altistart 480 series as a recommended replacement.

The ATS480M12Y is not automatically a direct electrical or mechanical replacement. Before substitution, engineers should compare:

• Rated supply voltage and control supply voltage.
• Motor power and current ratings.
• Line and inside-delta connection requirements.
• Standard-duty and severe-duty application requirements.
• Control terminals and signal assignments.
• Modbus communication configuration.
• Protection and monitoring functions.
• Cabinet dimensions and mounting arrangements.
• Cooling and ventilation requirements.
• PLC program and commissioning procedures.

A replacement project may require wiring changes, parameter conversion, control-system updates, and new commissioning tests.

Key Advantages

Controlled Starting for Large Motors

The ATS48M12Q is designed for large asynchronous motors and provides controlled acceleration to help reduce the impact of starting current and mechanical stress.

Torque-Controlled Operation

Its torque-control capability supports applications where smoother motor acceleration is important for the driven equipment and process.

High-Power Application Capability

The device supports large motor ratings, including applications up to 630 kW at 400 V with line connection and up to 710 kW at 400 V with connection to motor delta terminals under the specified application conditions.

Adjustable Current Limitation

Current limitation allows engineers to configure starting conditions according to motor requirements and available electrical supply capacity.

Motor and Starter Thermal Protection

Integrated thermal protection functions help monitor motor and starter operating conditions.

Modbus Communication

The RS485 Modbus interface supports communication with compatible PLCs and industrial control systems.

Industrial Application Flexibility

The Altistart 48 range is designed for pumping, ventilation, and other demanding industrial motor applications.

Technical FAQs

1. What is the Schneider Electric ATS48M12Q?

The ATS48M12Q is a high-capacity Altistart 48 soft starter designed for three-phase asynchronous motors. It provides controlled motor starting and stopping for demanding industrial applications.

2. What is the rated voltage range?

The documented rated supply voltage range is 230–415 V AC. The device supports 50/60 Hz power systems, with a frequency operating range of 47.5–63 Hz.

3. What is the current rating of the ATS48M12Q?

The product documentation identifies a factory-setting current of 1045 A. Other current figures depend on the connection method and application category. Always use the manufacturer’s selection tables when sizing the starter.

4. What motor power can it support?

At 400 V, the documented motor power is up to 630 kW for standard applications with line connection and up to 710 kW for severe applications with connection to the motor delta terminals.

The applicable rating must be determined from the actual motor current, connection arrangement, and operating duty.

5. Does the ATS48M12Q support Modbus?

Yes. It provides a serial Modbus communication interface using RS485. The communication settings must be configured to match the connected PLC or supervisory control system.

6. Does this soft starter provide motor protection?

Yes. It includes motor thermal protection, starter thermal protection, and line phase-failure protection. Correct configuration is required for the protection functions to operate as intended.

7. Can it be used for large pumps?

Yes. Pumping applications are among the intended uses of the Altistart 48 range. Controlled acceleration and deceleration can help manage mechanical and hydraulic stress in suitable installations.

8. Is the ATS48M12Q still available as a current-production model?

No. Schneider Electric has discontinued the ATS48M12Q. Existing units may still be available through industrial spare-parts suppliers, surplus inventories, or refurbished-equipment channels.

9. What is the recommended replacement?

Schneider Electric identifies the ATS480M12Y from the Altistart 480 series as a recommended replacement. The replacement must still be checked for electrical, mechanical, and control-system compatibility.

10. What should be checked before purchasing a used ATS48M12Q?

Verify the complete model number, nameplate information, physical condition, power terminals, control terminals, cooling components, and available test records. For critical applications, request functional testing and confirm the supplier’s warranty and return conditions.

Procurement and Maintenance Recommendations

The ATS48M12Q is a discontinued high-capacity soft starter, so accurate product identification is important when purchasing a replacement or spare unit.

Before ordering, confirm the model number and compare the nameplate ratings with the installed motor-control system. Pay particular attention to the rated supply voltage, current reference, motor power, connection method, and application duty.

For used or refurbished equipment, request photographs of the nameplate, power terminals, control terminals, and cooling components. Confirm whether the unit has been tested and whether accessories or external bypass equipment are included.

During maintenance, inspect electrical connections, cooling airflow, cabinet ventilation, grounding, and signs of overheating. Check the motor and starter protection settings against the actual motor data and application conditions.

For replacement planning, consider the ATS480M12Y but do not assume it is a plug-in substitute. Review the wiring diagrams, control interfaces, communication settings, cabinet dimensions, and commissioning requirements before changing the installed equipment.

Conclusion

The Schneider Electric ATS48M12Q Altistart 48 Soft Starter is a high-capacity motor-control device designed for large three-phase asynchronous motors. With a 230–415 V AC supply range, torque-controlled starting, adjustable current limitation, thermal protection, and Modbus RS485 communication, it is suited to demanding applications such as industrial pumping, ventilation, and heavy machinery.

The model has been discontinued, with the ATS480M12Y identified as its recommended successor. For maintenance and replacement projects, engineers should verify motor ratings, connection arrangements, protection requirements, and control-system compatibility before selecting a replacement.