Différence entre un commutateur de transfert automatique et un commutateur de transfert

Alt-text: Technician using a control panel in an industrial facility with power switch interface

Power disruptions aren’t just inconvenient—they can be costly or dangerous in critical environments. 

That’s why many facilities use a backup power system with some kind of switch that shifts the load between power sources. But choosing the right device can be tricky if you’re unsure of the difference between an automatic transfer switch and a changeover switch.

While both tools serve a similar purpose—switching power between sources—their features, levels of automation, and use cases are different. This guide simplifies the comparison so you can decide what fits your system best.

grossiste en fournitures électriques

Découvrez une gamme complète de produits électriques auprès d'un grossiste en fournitures électriques de confiance. TOSUNlux propose des disjoncteurs, des contacteurs, des interrupteurs et bien plus encore pour les marchés mondiaux.

Voir le produit

Understanding the Basics: ATS vs. Changeover Switch

Let’s start with what they are.

Un automatic transfer switch (ATS) is a smart device. It continuously monitors your main power supply and, when an outage or drop is detected, it automatically switches to your backup source (usually a generator) and can even start the generator itself.

UN commutateur de commutation, on the other hand, simply shifts the power connection between two sources. It can be manual or automatic, but most basic models don’t start or stop a generator—they just switch the power lines once the alternate source is already running.

In short, an ATS offers automation and speed, while a changeover switch focuses on simple source switching without generator control.

How Each Device Works

Automatic Transfer Switch (ATS)

An ATS stays on alert 24/7. It’s wired into both your utility and backup power lines. An ATS automatic transfer switch changeover system instantly responds when it detects a power outage or voltage drop. It starts the generator, waits until stable, transfers the load, and switches back when utility power is restored.

• Signals the backup generator to start
• Waits for the generator to stabilize
• Transfers the load from utility to generator
• Switches back automatically when utility power is restored

This kind of ATS automatic transfer switch changeover is ideal for setups where even a few seconds of downtime could cause major disruption—like hospitals, data centers, or security systems. 

Commutateur automatique

Un automatic changeover switch also transfers load between two sources but doesn’t manage the generator itself. It typically activates once the generator is already up and running, or once a second power source (like an inverter or secondary utility feed) is available.

TOSUNlux offers industrial-grade Commutateurs automatiques with options for 2P, 3P, and 4P connections, handling up to 1000V and built with thermal overload protection, phase detection, and clear indicator lights. These are designed for commercial and industrial settings where simple but reliable switching is key.

Commutateur EP

Fiable et compact, le commutateur de commutation TOSUNlux EP permet une transition de source d'alimentation en douceur, idéal pour les systèmes de secours et les panneaux industriels.

Voir le produit

ATS vs. Changeover Switch: Clear Comparison

To make it easier to see how these devices differ, here’s a simple side-by-side view of their main features:

The automatic changeover switch vs automatic transfer switch decision really comes down to how critical your power continuity is—and whether you need the switch to control your generator directly.

When to Use Each One

Now that you understand how they work, let’s talk about when to use an ATS vs. a changeover switch. Choosing the right one depends on how critical your operations are and how much control you want from the system.

If you operate in an environment where any power interruption is unacceptable—like hospitals, data centers, telecom rooms, or manufacturing lines—an ATS is the clear choice. It handles everything automatically: detecting the outage, starting the generator, and transferring power without needing human input.

On the other hand, a changeover switch is better suited for setups where a brief pause is acceptable or a generator is already started manually or through another controller. These switches are common in:

• Warehouses and workshops
• Small businesses
• Backup systems for homes
• Agricultural sites with two power feeds

Changeover switches are also easier to install and more budget-friendly, especially when generator automation isn’t a priority.

Inside TOSUNlux’s Automatic Changeover Switch

TOSUNlux manufactures a line of Automatic Changeover Switches specifically built for industrial and commercial use. These switches make it easy to switch between power sources and include built-in protection and monitoring functions.

Commutateur CA10

Le commutateur de commutation TOSUNlux CA10 assure une commutation sûre et fiable entre les sources d'alimentation dans les applications industrielles et commerciales.

Voir le produit

Key features include:

• Wide voltage range: Supports up to 1000V systems
• Thermal overload protection: Prevents overcurrent damage
• Clear indicator lights: Show active power source and system status
• Phase detection and time delay: Ensures switching only happens under safe conditions
• DIN-rail or panel mounting: Fits cleanly into most setups

They are ideal for businesses that don’t need generator control but still want automated switchover between two power sources, such as utility and inverter or two supply lines.

By using a TOSUNlux switch, you’re getting industrial-grade durability and precision from a specialist manufacturer trusted in over 90 countries.

Choosing Between ATS and Changeover: Key Considerations

Making the right decision starts with identifying your priorities. Ask yourself:

Do I need generator automation?

If yes, go with an ATS.

Is downtime a critical risk to my operations?

For zero-delay transitions, an ATS is essential.

Am I switching between two live sources (like grid + inverter)?

UN commutateur de commutation works well in these cases.

Is cost a major factor?

Changeover switches usually cost less and demand minimal upkeep.

Both switches serve valuable roles, but they solve different problems. It’s not about which is “better,” but which is more appropriate for your setup.

Common Mistakes to Avoid

When setting up either system, make sure you avoid these:

• Underrating the switch: Never undersize your switch—make sure it meets or exceeds the system’s current and voltage requirements.
• No interlock protection: Never allow both sources to connect at the same time—your switch should have mechanical or electrical interlock.
• Skipping testing: Even with an ATS, test your switching cycle regularly under load.
• Mixing manual and auto systems without planning: If you have a manual generator but want auto switchover, you’ll need a hybrid control approach—not just a basic switch.

Difference Between Automatic Transfer Switch and Changeover Switch: Conclusion

The difference between automatic transfer switch and changeover switch isn’t complicated—but it’s critical to understand before installing any backup system.

• Choose an ATS automatic transfer switch changeover setup when you need hands-free backup switching, built-in generator control, and zero manual intervention. 
• Use a commutateur de commutation when switching between sources is still important, but you don’t need full automation or generator management.
  

If you’re looking for a reliable, cost-effective automatic changeover switch, TOSUNlux delivers. 

With industrial-grade protection, built-in delay, overload safety, and clean mounting options, it’s built for professionals who value performance and simplicity.

Atteindre to us to know more!