Product Overview

The Schneider ATS22C11S6U Soft Starter is an Altistart 22 motor starter used with three-phase asynchronous motors. It is intended for fixed-speed machinery where the motor needs a controlled transition during startup and, where required, during stopping.

In a conventional direct-on-line arrangement, a motor is connected to the supply with little control over the initial acceleration event. That can be acceptable for small or lightly loaded machines, but larger rotating loads may produce a sharp torque response and a noticeable mechanical impact.

The ATS22C11S6U is suited to situations such as pump stations, ventilation equipment, conveyors, compressors, and general process machinery. For example, when a conveyor starts with material already on the belt, the motor has to accelerate both the drive system and the load. A controlled starting sequence can reduce the abrupt transition through the gearbox, coupling, and belt.

The ATS22C11S6U belongs to the Altistart 22 family. It is intended for motor starting and stopping control rather than continuous speed regulation, so applications requiring variable running speed would normally call for a different type of motor controller.

Technical Specifications

Product Features

The ATS22C11S6U combines controlled acceleration and deceleration with the functions needed for fixed-speed asynchronous motor applications.

Key characteristics include:

• 11 A rated operational current
• 208–600 V AC supply range
• 110–230 V AC control supply
• Three-phase asynchronous motor operation
• 50–60 Hz operating frequency
• In-line or inside-the-delta connection
• AC-53A utilization category
• Controlled motor acceleration
• Controlled motor deceleration
• Suitable for fixed-speed motor systems
• Applicable to pumps, fans, conveyors, and compressors
• Suitable for industrial motor-control cabinets
• Dimensions of 356 × 150 × 229.5 mm
• Stated weight of 18 kg

The wide supply range makes this version useful where the motor system may operate on different industrial voltage levels. Even so, the motor nameplate, connection arrangement, starting duty, and actual application conditions should be checked before installation.

Working Principle

The ATS22C11S6U is installed within the motor feeder:

Three-Phase Supply → Motor Protection → ATS22C11S6U → Asynchronous Motor → Mechanical Load

When the motor receives a start command, the starter manages the acceleration process rather than applying the motor’s full starting condition abruptly.

Consider a pump with a relatively large rotating assembly. At startup, the motor has to accelerate the rotor and connected equipment from zero speed. A conveyor presents another example: the motor may need to accelerate the belt, rollers, gearbox, coupling, and material at the same time.

The soft starter manages this transition so the motor’s acceleration is controlled according to the application. It can also manage the stopping process when a gradual reduction in motor operation is preferable to an immediate interruption.

The key point is that the ATS22C11S6U is a soft starter, not a variable frequency drive. After the motor reaches its normal operating condition, the machine continues to operate as a fixed-speed motor system.

Industrial Applications

The ATS22C11S6U can be used on industrial machines where controlled motor starting and stopping are more important than continuous speed adjustment.

The motor’s current rating alone does not determine suitability. The driven load, starting frequency, acceleration time, mechanical inertia, and operating environment should also be considered.

Compatible System Components

The ATS22C11S6U normally works together with several electrical and mechanical components.

Correct coordination between the starter, motor protection, motor, and control system is important. A problem in any of these areas can appear as a starting fault even when the soft starter itself is operating normally.

Installation and Maintenance

The ATS22C11S6U should be installed in an appropriate control cabinet with sufficient ventilation and enough working space around the power and control terminals.

Before energizing the system, compare the motor nameplate with the starter ratings. Pay particular attention to motor current, supply voltage, control supply, connection arrangement, and expected starting frequency.

Recommended checks include:

• Confirm the complete ATS22C11S6U part number.
• Verify the motor nameplate current.
• Check the incoming three-phase voltage.
• Confirm the control supply voltage.
• Verify the selected in-line or inside-the-delta connection.
• Check upstream motor protection.
• Inspect motor power connections.
• Check control wiring.
• Verify start/stop commands.
• Inspect terminals for looseness or signs of overheating.
• Confirm adequate cabinet ventilation.
• Review the expected starting frequency.
• Consider the mechanical inertia of the driven equipment.
• Check diagnostic information after commissioning.
• Perform a controlled startup test before normal operation.

If the starter trips during acceleration, inspect the motor and mechanical load as well as the electrical circuit. Excessive load, incorrect motor wiring, inadequate supply conditions, unsuitable protection settings, or excessive starting frequency can all affect the startup sequence.

Recommended Related Models

For the ATS22C11S6U, related products should be selected according to supply requirements, motor current, and the complexity of the application.

The ATS22C11S6 and ATS22C11Q are useful comparison models within the same Altistart 22 family, but their electrical configurations should be checked carefully before substitution.

For simpler fixed-speed machines, an ATS130 model may be considered where the application requirements match that family. The ATS480 family is more appropriate when the machine requires a broader range of motor-control and commissioning capabilities.

A replacement decision should consider the motor’s current, supply voltage, control voltage, connection method, starting duty, and cabinet installation rather than relying only on the model’s physical dimensions.

Key Advantages

• 11 A rated operational current
• 208–600 V AC supply range
• 110–230 V AC control supply
• Three-phase asynchronous motor operation
• In-line or inside-the-delta connection
• AC-53A utilization category
• Controlled acceleration
• Controlled deceleration
• Suitable for fixed-speed industrial machinery
• Suitable for pumps, fans, conveyors, and compressors
• Dimensions of 356 × 150 × 229.5 mm
• Stated weight of 18 kg

Technical FAQs

What does the “S6U” designation indicate for this ATS22 model?

The ATS22C11S6U is a specific variant within the Altistart 22 family, and its electrical configuration differs from other 11 A models such as the ATS22C11Q. The complete model number should therefore be checked when replacing an existing unit rather than treating all ATS22 11 A versions as interchangeable.

Can the ATS22C11S6U handle a motor with frequent starts?

The motor’s rated current is only one part of the selection process. Frequent starts increase thermal and operating demands on the starter, so the required starting frequency, acceleration time, motor load, and application duty should be evaluated before installation.

When is an inside-the-delta connection useful?

An inside-the-delta connection places the soft starter within the motor’s delta circuit rather than directly in the incoming line. It can be used with compatible motor winding arrangements and can reduce the current handled by the starter compared with an equivalent in-line arrangement. The motor and starter connection requirements must be verified before use.

What symptoms suggest that the mechanical load should be checked rather than the soft starter replaced?

Slow acceleration, repeated startup trips, excessive motor current, or failure to reach operating speed can result from excessive load or mechanical resistance. The pump, fan, conveyor, gearbox, coupling, or other driven equipment should be inspected before concluding that the ATS22C11S6U has failed.