Product Overview

The Schneider ATS22C21Q is an industrial soft starter from the Schneider Altistart 22 family, designed to provide controlled starting and stopping for three-phase asynchronous motors. It is intended for motor-driven equipment where direct-on-line starting may create excessive electrical current, mechanical shock, or unnecessary stress on connected machinery.

In industrial facilities, motors are frequently connected to pumps, fans, compressors, conveyors, mixers, and other mechanical loads. When a motor is started directly across the line, the sudden application of full voltage can result in a high inrush current and rapid torque development. For large or mechanically sensitive equipment, this starting behavior can affect the motor, transmission components, belts, couplings, pipes, and driven machinery.

The ATS22C21Q addresses this requirement by providing a controlled motor-starting process. Instead of allowing the motor to accelerate instantaneously from a stopped condition, the soft starter manages the electrical conditions during acceleration so that the motor can reach operating speed in a more controlled manner.

The device can also be used where controlled stopping is desirable. For example, certain pumping systems may benefit from a more gradual stopping process, while conveyors and mechanical systems can use controlled deceleration to reduce sudden loading or movement.

The supplied dimensions of the ATS22C21Q are approximately 425 × 206 × 299 mm, and the supplied weight is approximately 33 kg. These physical characteristics should be considered carefully when designing the electrical cabinet, mounting structure, ventilation system, and maintenance access.

Technical Specifications

What Is the Schneider ATS22C21Q?

The Schneider ATS22C21Q is a motor soft starter used to control the starting and stopping behavior of compatible three-phase motors. It belongs to the Altistart 22 product family and is designed for industrial motor-control applications.

The primary purpose of a soft starter is to provide a more controlled transition between the motor’s stopped state and its normal operating condition. During direct-on-line starting, a motor can draw a substantial current from the electrical supply while simultaneously producing a rapid increase in torque.

For a small motor connected to a lightly loaded machine, this may not present a significant problem. However, large industrial motors can impose considerable demands on electrical infrastructure and mechanical transmission systems during startup.

A soft starter changes this starting behavior by controlling the voltage applied to the motor during acceleration. The motor is allowed to build up speed progressively instead of receiving the full electrical supply instantaneously.

This makes the ATS22C21Q particularly useful in applications where the motor and mechanical load need a smoother starting sequence.

Function and Working Principle

The basic operating arrangement of the ATS22C21Q can be represented as:

Three-Phase Power Supply → Protection → ATS22C21Q → Motor → Mechanical Load

When the control system issues a start command, the soft starter initiates its configured starting sequence. The power-control circuitry regulates the motor’s applied voltage during acceleration.

As the motor accelerates, the electrical conditions are progressively changed until the motor reaches normal operating speed. The result is a smoother transition than conventional direct-on-line starting.

This controlled acceleration can provide several practical benefits. Mechanical components may experience less sudden torque, while the electrical system can experience a less abrupt starting event.

Depending on the application configuration, controlled stopping can also be used. Instead of immediately removing the motor from operation, the soft starter can provide a more gradual stopping sequence when this behavior is appropriate for the connected load.

It is important to understand that a soft starter is not designed to provide the same continuous speed-control capability as a variable frequency drive. The ATS22C21Q is primarily selected when controlled starting and stopping are required without the need for continuous variable-speed operation.

Why Use a Soft Starter for Industrial Motors?

Large motor systems can create significant electrical and mechanical stresses during startup. Direct-on-line starting is simple, but it may not be the best solution for every industrial application.

Typical problems associated with uncontrolled motor starting can include:

• High inrush current
• Voltage dips within the electrical system
• Sudden mechanical torque
• Stress on shafts and couplings
• Belt and gearbox shock
• Mechanical vibration
• Hydraulic shock in pump systems
• Increased stress on driven equipment

By controlling the motor starting process, a soft starter can help create a more predictable acceleration profile.

The actual benefit depends on the motor, load, starting conditions, electrical system, and configuration. Correct sizing and commissioning are therefore essential.

Role in Industrial Control Systems

The ATS22C21Q can operate as part of a larger motor-control and automation system. A PLC may provide the start and stop commands, while the soft starter manages the motor’s electrical starting characteristics.

A typical industrial installation may include:

• PLC controller
• HMI operator interface
• Motor protection equipment
• Incoming circuit breaker
• ATS22C21Q soft starter
• Motor contactor
• Three-phase motor
• Emergency stop circuit
• Control power supply
• Industrial communication network
• Process sensors

This architecture allows the motor to become part of an automated production sequence. For example, a PLC can start a conveyor after receiving a permissive signal, while the ATS22C21Q manages the acceleration of the conveyor motor.

Status and fault information can also be incorporated into the automation system where supported by the selected control and communication configuration.

Industrial Applications

Pump Stations

Pump motors are a common application for soft starters. Controlled acceleration and stopping can help reduce sudden mechanical and hydraulic effects, especially in larger pumping systems.

Industrial Fans

Large fans and blowers can contain significant rotating mass. A controlled start allows the rotating assembly to accelerate progressively and can reduce sudden mechanical loading.

Conveyor Systems

Heavy conveyor belts can experience substantial mechanical forces during direct starting. A soft starter can provide a smoother acceleration sequence, which may reduce stress on belts, shafts, couplings, and gearboxes.

Compressors

Industrial compressors often use high-power motors. Controlled motor starting can help manage the startup process and reduce unnecessary mechanical shock.

Mixers and Agitators

Mixing equipment can have significant starting resistance depending on the material being processed. A controlled start can provide a more gradual application of motor torque.

Material Handling Equipment

Industrial material-handling systems may use motors connected to gearboxes, belts, rollers, or other mechanical systems. Soft starting can help reduce abrupt loading during machine startup.

HVAC Equipment

Large air-handling systems and ventilation equipment can use soft starters when controlled motor acceleration is required but continuous variable-speed operation is not necessary.

Installation and System Integration

Correct installation of the ATS22C21Q requires coordination between electrical protection, motor characteristics, control wiring, mechanical installation, and cabinet thermal management.

Motor Verification

Before connecting the soft starter, verify the motor nameplate voltage, current, frequency, power rating, connection method, and operating duty.

The soft starter should be selected according to the motor’s actual operating requirements rather than simply matching the motor horsepower.

Power Supply Verification

Confirm that the incoming three-phase supply is appropriate for the selected ATS22 configuration. Supply conditions should be checked before energizing the system.

Protection and Isolation

The soft starter should be installed with suitable upstream protection and isolation equipment. Short-circuit protection, motor protection, and disconnecting arrangements should be designed for the complete installation.

Cabinet Installation

The ATS22C21Q has supplied dimensions of 425 × 206 × 299 mm and a supplied weight of approximately 33 kg. The mounting structure should be strong enough to support the device and associated wiring.

Because the equipment uses forced-air cooling, the cabinet should provide sufficient ventilation and appropriate airflow. Heat generated by the soft starter should be considered during cabinet thermal design.

Control Wiring

Start, stop, fault, and status signals should be connected according to the control architecture. When integrated with a PLC, the control sequence should include appropriate permissives and safety interlocks.

Motor Connections

Motor power connections must be carefully inspected before commissioning. Incorrect connections can lead to abnormal motor operation, excessive current, or failure to start.

Parameter Configuration

Motor current and starting parameters should be configured according to the motor and mechanical load. A pump, conveyor, fan, and compressor may require different starting characteristics.

Commissioning

During commissioning, verify motor rotation direction, starting current, acceleration time, stopping behavior, fault indications, and PLC control signals. Testing should be completed before the machine is placed into normal production.

Compatible System Components

Recommended Alternative Models

When selecting an alternative to the ATS22C21Q, engineers should compare the complete model number rather than selecting a device based only on physical dimensions. Motor current, supply voltage, control voltage, starting duty, application type, and communication requirements should all be evaluated.

Key Advantages

• Designed for industrial three-phase motor starting applications
• Provides controlled acceleration instead of abrupt direct starting
• Helps reduce mechanical shock during motor startup
• Can help reduce the impact of high starting current
• Suitable for pumps, fans, conveyors, compressors, and mixers
• Can be integrated with PLC-based control systems
• Suitable for industrial motor-control cabinets
• Supports controlled stopping for suitable applications
• Large industrial frame for higher-capacity motor applications
• Supplied dimensions of approximately 425 × 206 × 299 mm
• Supplied weight of approximately 33 kg

Technical FAQs

What is the Schneider ATS22C21Q?

The Schneider ATS22C21Q is an Altistart 22 industrial soft starter designed to control the starting and stopping of compatible three-phase asynchronous motors.

What is the main function of the ATS22C21Q?

Its main function is to provide controlled motor acceleration and stopping, helping reduce the electrical and mechanical stress that can occur during direct-on-line starting.

Is the ATS22C21Q suitable for pumps?

Yes. Pump systems are a common application for soft starters because controlled acceleration and stopping can help reduce mechanical and hydraulic disturbances.

Can the ATS22C21Q be used with a PLC?

Yes. The soft starter can be incorporated into a PLC-based motor-control architecture. The PLC can manage the machine sequence while the soft starter controls the motor-starting process.

Is the ATS22C21Q a variable frequency drive?

No. It is a soft starter rather than a variable frequency drive. It is intended primarily for controlled starting and stopping, while a variable frequency drive is normally used when continuous motor-speed regulation is required.

What is the difference between a soft starter and a contactor?

A conventional contactor primarily switches the motor supply on or off. A soft starter actively manages the motor starting process to provide a controlled acceleration profile.

What are the dimensions of the ATS22C21Q?

The supplied dimensions are approximately 425 × 206 × 299 mm.

What is the weight of the ATS22C21Q?

The supplied product weight is approximately 33 kg.

What should be checked before replacing an ATS22C21Q?

Check the motor rated current, supply voltage, control voltage, starting duty, load characteristics, cabinet dimensions, cooling requirements, control wiring, and communication requirements. The complete model number should be compared before selecting a replacement.

What can cause an ATS22C21Q motor to fail to start?

Possible causes include missing incoming power, an incorrect control signal, protection-device operation, incorrect motor wiring, unsuitable motor parameters, excessive mechanical load, or a soft-starter fault. Troubleshooting should begin with power and control verification before replacing hardware.

Conclusion

The Schneider ATS22C21Q Soft Starter is an industrial motor-control solution designed to provide a more controlled starting and stopping process for three-phase asynchronous motors. By gradually managing motor acceleration, it can help reduce sudden torque and mechanical stress compared with conventional direct-on-line starting.

With supplied dimensions of approximately 425 × 206 × 299 mm and a supplied weight of approximately 33 kg, the ATS22C21Q is intended for substantial industrial control installations where appropriate cabinet space, mechanical support, and thermal management are required.

The device can be integrated with PLCs, HMIs, protection equipment, contactors, motors, sensors, and other industrial control components. Its application range includes pumps, fans, conveyors, compressors, mixers, material-handling systems, and other motor-driven machinery.

For electrical engineers, system integrators, OEM machine builders, and maintenance professionals, correct selection is essential. Motor current, supply conditions, starting duty, mechanical load, protection requirements, and control architecture should all be evaluated before commissioning. When properly matched to the application, the Schneider ATS22C21Q can provide reliable and controlled motor starting for demanding industrial automation systems.