How does ATS work with generators

Understanding ATS

Purpose of ATS

The main function of an ATS is to automatically switch the electrical load from the utility to a generator during a fault, and switch back when utility power returns. This automated process avoids interruptions and safeguards sensitive equipment from outages.

Key Components of an ATS

Switches

The switches in an ATS transfer loads between power sources. They connect only one power source at a time to the load, preventing backfeed and maintaining safe operation.

Control Circuits

Control circuits are the brains of the ATS. They monitor the power status and control the switching process. These circuits detect voltage drops or faults and initiate the transfer process. Once normal power is restored, they manage the transfer back to utility power.

Types of ATS

Open Transfer

Open transfer switches briefly disconnect power when switching between power sources. While this causes a brief interruption, it is sufficient for most applications where a momentary power outage can be acceptable.

Enclosed Transfer

Enclosed transfer switches ensure seamless transfers without interrupting power. They temporarily connect the two power sources to ensure continuity, making them ideal for critical systems where even a brief power outage is unacceptable.

Static Transfer Switches

Static transfer switches use electronic components rather than mechanical components to transfer loads. This allows for extremely fast switching, suitable for applications where power needs to be transferred instantly without any delays.

These ATS types offer flexibility, allowing users to select the most appropriate option for their specific power reliability needs. Understanding these differences is critical when designing a backup power solution for unique operational requirements.

How an ATS Works with Generators

Power Failure Detection

The ATS continuously monitors the incoming utility power for abnormal conditions such as voltage drops or complete power outages. It uses specially designed sensors to detect these interruptions in a timely manner. When the ATS detects a power failure, it verifies that the utility power is indeed lost and a switchover is required. It immediately begins the transfer process.

Generator Activation

The ATS sends a start signal to the generator to initiate its operation.

It is also worth noting that a time delay is programmed into the ATS to prevent unnecessary generator starts during brief power failures. This delay also allows the generator to warm up and stabilize, ensuring optimal performance.

Load Transfer

Once the generator reaches appropriate operating parameters, ATS transfers the load from the utility power to generator. This requires disconnecting the utility power and connecting generator to the load. Before the actual load transfer, ATS ensures that voltage and frequency of generator are synchronized with the requirements of the load to maintain stability and prevent damage.

Monitoring Power Quality

During generator operation, the ATS continuously checks voltage, frequency and current parameters to ensure they are within acceptable ranges for safe operation. If any anomalies or faults are detected, ATS initiates an automatic shutdown to protect generator and connected equipment.

Switching Back to Primary Power

The ATS monitors the restoration of utility power. It detects when primary power is stable and within preset thresholds and switches back to primary power.

To ensure a safe return to utility power, the ATS checks that voltage, frequency, and any power conditions are stable before switching the load.

Reconnection Process

After confirming that utility power is stable, the ATS switches the load back to utility power and disconnects generator. Waiting for generator to cool down allows generator to run without load, dissipate excess heat, and ensure long life and ready availability. Once cooled down, the generator receives a signal to shut off.