Product Overview

The Schneider ATS22C41S6U Soft Starter for Asynchronous Motor is an Altistart 22 soft starter intended for three-phase asynchronous motor applications where direct-on-line starting would produce excessive starting current or mechanical shock.

Instead of applying full motor voltage immediately, the soft starter manages the motor’s acceleration and stopping process. This makes it useful for fixed-speed machines where the main requirement is controlled starting and stopping rather than continuous speed regulation.

The ATS22C41S6U is suited to equipment such as pumps, fans, conveyors, compressors, and other industrial machinery with significant starting inertia or mechanical systems that benefit from reduced starting shock. It can be installed as part of a conventional motor feeder together with upstream protection, contactors, motor cabling, and the associated control system.

The ATS22C41S6U belongs to the Altistart 22 family. It should not be confused with a variable frequency drive: once the motor has completed its starting sequence, the soft starter is primarily used to support a fixed-speed motor application rather than continuously regulate motor speed.

Technical Specifications

The electrical configuration should be checked against the motor nameplate and the complete motor feeder before installation. Motor current, supply voltage, starting duty, connection method, and application load are particularly important when selecting an Altistart 22 soft starter.

Product Features

The ATS22C41S6U is intended for motor applications where the starting process needs to be controlled without introducing the continuous speed-control functions normally associated with a variable frequency drive.

Key characteristics include:

• Schneider Electric Altistart 22 soft starter
• Designed for three-phase asynchronous motors
• Controlled motor acceleration
• Controlled motor deceleration
• Suitable for fixed-speed motor applications
• Suitable for pumps, fans, conveyors, and compressors
• Helps reduce mechanical shock during motor starting
• Helps manage motor starting current
• Suitable for industrial motor-control cabinets
• Supports conventional motor feeder architectures
• Dimensions of 425 × 206 × 299 mm
• Stated weight of 33 kg

The actual starting performance depends on the motor, driven load, starting frequency, ramp settings, supply conditions, and mechanical characteristics of the machine.

Working Principle

The ATS22C41S6U controls the voltage applied to the motor during the starting process rather than switching the motor directly from zero to full supply conditions.

A simplified motor circuit is:

Three-Phase Supply → Protection → ATS22C41S6U → Motor → Mechanical Load

When a start command is issued, the soft starter gradually brings the motor toward normal operating conditions. This controlled transition reduces the abrupt torque response associated with direct-on-line starting.

The effect is particularly useful with machines that have substantial inertia. A large fan, loaded conveyor, or pump system can require considerable torque to move from standstill. Applying full voltage immediately can produce a sharp mechanical response through shafts, couplings, gearboxes, belts, and other transmission components.

During stopping, the soft starter can also provide controlled deceleration where the application requires a more gradual reduction in motor operation.

The ATS22C41S6U is therefore primarily concerned with the starting and stopping behavior of the motor. It does not provide the same continuous speed-control function as a variable frequency drive.

Role in a Motor Starting System

The ATS22C41S6U forms the controlled-starting stage of a conventional fixed-speed motor system.

A typical architecture is:

Incoming AC Supply → Circuit Protection → Switching / Isolation → ATS22C41S6U → Asynchronous Motor → Mechanical Load

The soft starter works together with the motor protection and switching components rather than replacing them.

For example, the upstream protection device handles feeder protection, while the soft starter manages the motor’s acceleration profile. The motor then operates the connected pump, fan, conveyor, compressor, or other machine.

This separation of functions is important when troubleshooting. A motor that fails to accelerate may have a problem with the starter, but it could also be affected by incorrect motor connections, inadequate supply conditions, excessive mechanical load, incorrect protection settings, or an unsuitable starting cycle.

Industrial Applications

The ATS22C41S6U is suitable for industrial machines using three-phase asynchronous motors where controlled starting or stopping is required.

The correct soft starter rating should be determined from the motor’s actual operating current and application duty rather than from motor power alone.

Installation and Maintenance

The ATS22C41S6U should be installed inside an appropriately sized control cabinet with adequate ventilation, electrical clearance, and access for inspection and maintenance.

Because a soft starter handles substantial motor power, the installation should be treated as part of the complete motor feeder. Upstream protection, switching devices, motor cabling, grounding, and the driven machine all need to be checked.

Recommended installation and maintenance checks include:

• Confirm the complete ATS22C41S6U part number.
• Check the motor nameplate current.
• Verify the incoming three-phase supply.
• Confirm the motor connection arrangement.
• Check upstream circuit protection.
• Verify the control wiring.
• Inspect power terminals for secure connections.
• Confirm appropriate cabinet ventilation.
• Check the expected number of motor starts per hour.
• Consider the motor’s mechanical load and inertia.
• Inspect power cables for overheating or damage.
• Check diagnostic information after commissioning.
• Perform a controlled startup test.
• Verify stopping behavior under normal load.
• Inspect terminals periodically for signs of overheating.

If the motor trips during acceleration, do not immediately replace the soft starter. First determine whether the motor is overloaded, the acceleration period is inappropriate, the incoming supply is unstable, or the mechanical load requires more starting torque than expected.

Related Components

The ATS22C41S6U normally operates as part of a complete motor-control assembly.

Correct coordination between the soft starter and motor protection is essential. The starter manages motor starting behavior, while the surrounding protection equipment provides the necessary feeder and fault protection.

Recommended Related Models

For an ATS22C41S6U installation, related Schneider motor-control products should be selected according to motor current, supply voltage, application duty, and required control functions.

The ATS130 family can be considered for simpler applications where its electrical ratings and functions match the motor requirements. The ATS480 family is more appropriate when the installation requires broader motor-management capabilities.

For a direct replacement, the motor’s rated current, supply voltage, connection method, starting duty, and cabinet arrangement should all be verified before selecting another model.

Key Advantages

• Schneider Electric Altistart 22 soft starter.
• Designed for three-phase asynchronous motor applications.
• Controls motor acceleration during startup.
• Supports controlled motor stopping.
• Helps reduce mechanical shock during starting.
• Helps manage demanding motor-starting conditions.
• Suitable for pumps, fans, conveyors, compressors, and fixed-speed machinery.
• Integrates with conventional motor protection and switching equipment.
• Suitable for industrial control cabinets.
• Dimensions of 425 × 206 × 299 mm.
• Stated weight of 33 kg.

Technical FAQs

What type of motor application is the ATS22C41S6U intended for?

The ATS22C41S6U is intended for fixed-speed applications using three-phase asynchronous motors where controlled acceleration and stopping are required. Typical examples include pumps, fans, conveyors, compressors, and other machinery with demanding starting characteristics.

What information should be checked before sizing the ATS22C41S6U for a motor?

The motor’s rated current should be treated as a primary selection parameter, followed by supply voltage, connection arrangement, starting frequency, load inertia, acceleration requirements, and operating conditions. Motor power alone is not sufficient for reliable soft-starter selection.

Why might a high-inertia load fail to accelerate even though the soft starter powers up normally?

The issue may be related to the available starting torque, acceleration settings, motor loading, supply conditions, or mechanical resistance. A fan, conveyor, or other high-inertia machine can require substantially different starting behavior from a lightly loaded motor, so the mechanical load should be evaluated together with the electrical parameters.

When should an Altistart 22 soft starter be replaced by a variable frequency drive instead?

A soft starter is appropriate when the motor normally runs at a fixed speed and the main requirement is controlled starting and stopping. If the process requires continuous speed adjustment, torque control over a wide speed range, or frequent speed changes during operation, a variable frequency drive is generally the more appropriate technology.