The core function of an ATS is to automatically switch the power supply from the main source to a backup source when the main power fails, and then switch back to the main power once it is restored. The typical working process of an ATS is as follows:

1. Normal Condition

When the main power supply (usually utility power) is operating normally, the intelligent controller detects that the power is stable. The main power switch remains closed and continuously supplies electricity to the load.

2. Fault Detection

The controller continuously monitors parameters such as voltage and frequency of the main power supply. Once an abnormal condition or failure is detected, the system immediately enters the transfer process.

3. Delay Confirmation

To prevent false switching caused by temporary fluctuations, the system applies an adjustable short delay (typically 0–6 seconds, with 1 second being the most common) to confirm that the fault is real.

4. Backup Power Source Start

If the backup power source is a generator, the controller sends a start signal. After the generator successfully starts and its voltage and frequency reach the rated values, the backup power switch is ready to close.

5. Power Transfer

The main power switch opens first, and then the backup power switch closes. This sequence ensures that the two power sources are never connected simultaneously, allowing the load to be safely transferred to the backup power supply.

6. Power Restoration

Once the main power supply returns to normal and remains stable after an adjustable long delay (usually 0–30 minutes), the system automatically transfers the load back from the backup power source to the main supply. The generator then runs for a short no-load cooling period before shutting down.

This entire automatic switching process typically takes only a few seconds—or even less—minimizing the impact of power outages so effectively that users may not even notice any interruption in power supply.

FAQs

1. What is the basic working principle of an automatic transfer switch (ATS)?

It continuously monitors the main power and automatically switches to a backup source when failure occurs. In Wondon projects, it acts as an “automatic power switcher” between two power supplies.

2. How does an ATS detect a power failure?

It monitors voltage, frequency, and circuit stability in real time. Wondon systems rely on this monitoring to trigger instant switching when abnormal conditions appear.

3. What happens when the main power is restored?

The ATS automatically switches the load back to the main supply. Wondon designs ensure this transfer is smooth and does not disrupt connected equipment.

4. Is there any interruption during switching?

In most cases, switching happens within milliseconds to seconds, depending on the type. Wondon usually selects the ATS type based on how sensitive the customer’s load is.

5. What makes ATS reliable in continuous operation?

It has automatic detection, a fast switching mechanism, and a dual-source configuration. Wondon integrates these features to ensure a stable and uninterrupted power supply for critical systems.

dual power ATS automatic transfer switch