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What is the ATS panel of the diesel generator?

In the modern world, dependent on electricity, the availability of reliable backup power is essential. This applies to both domestic consumers and industrial enterprises, hospitals, data centers and other critical infrastructures. One of the most common sources of backup power is the diesel generator. But in order for this generator to automatically come into operation when the main power supply is interrupted, a device is needed to control the process – this is the role of the ATS panel (Automatic Backup Switching).

What is an ATS panel?

An ATS panel is an automated system that monitors the main power supply (grid) and, when a problem is detected (a drop or a complete outage), automatically triggers the start of the diesel generator. It then transfers power from the grid to the generator, thus ensuring uninterrupted power supply to the connected consumers.

Once the main power supply is restored, the ATS panel returns power back to the grid and stops the generator. All this happens without human intervention.

Principle of operation

1. Normal state – power supply from the grid

While the power grid is operating normally, the ATS panel simply monitors the voltage, frequency and phase parameters. The generator is in the off state and is not used.

2. Fault detection

When the grid power is interrupted or a critical voltage deviation is registered (for example, a drop below 180V in a 230V system), the panel triggers a timer to confirm the interruption (usually 2–5 seconds to avoid false signals).

3. Generator start

The ATS commands the diesel generator to start. The generator controller sends a signal to start. Once the generator reaches stable operating parameters (voltage, frequency), which may take 5–10 seconds, the panel switches the power supply from the grid to the generator.

4. Generator operation

During the interruption time, all connected loads are powered by the generator. The ATS continues to monitor the restoration of the main grid.

5. Grid restoration

After the grid power is restored and stabilized for a certain time (usually 30–60 seconds), the ATS panel performs the reverse switchover – transfers the load back to the grid.

6. Generator shutdown

After the grid power is restored, the generator remains on for a short time (“cooling” mode) and then automatically shuts down.

Main components of an ATS panel

An ATS panel contains various electrical and electronic elements that together ensure the accurate and safe operation of the system. The most common components include:

1. Controller (logic unit)

The central “brain” of the ATS panel. It monitors the grid voltage, controls the generator start and stop, performs switching between sources and protects the system.

2. Contactors or circuit breakers

They are used for physical switching between the grid and the generator. These elements must be coordinated with the load power.

3. Voltage and phase relays

Measure the input voltage parameters and detect anomalies such as phase shifts, low or high voltage, phase loss, etc.

4. Delay systems and timers

Used to introduce a delay in switching (to avoid momentary drops and fluctuations).

5. Signal indicators and alarms

Light or sound signals that indicate the current state of the system – network active, generator on, failure, shutdown, etc.

6. Manual/automatic modes

Most ATS panels have the ability to choose between automatic and manual operating modes, which is useful for servicing or testing.

The ATS panel is an indispensable component in diesel generator backup power supply systems. It provides automatic, reliable and safe switching between the network and the generator, protecting the equipment and providing comfort and security to users.