Understanding the Transfer Time of Automatic Transfer Switches During a Power Outage

When the power goes out at your home or business, every second counts. That’s why it’s essential to have a reliable automatic transfer switch (ATS) paired with your emergency backup generator. But how long does it take for the ATS to transfer power from the utility to your generator? Let’s break down the process to help you understand what to expect and how to ensure minimal downtime during an outage.

What is an Automatic Transfer Switch (ATS)?

An Automatic Transfer Switch is a device that automatically transfers the load from the utility power to the generator power during a power outage. It ensures a seamless transition to backup power without manual intervention, which is crucial for businesses that rely on continuous power to operate.

The Transfer Process

1. Detection of Power Loss: The ATS constantly monitors the voltage and frequency of the utility power. When it detects a significant drop or complete loss of power, it initiates the transfer process. This detection usually happens within a fraction of a second (milliseconds).
2. Generator Start-Up: Once the ATS detects a power loss, it sends a signal to the generator to start. Modern generators are designed to start up quickly, typically within 2-10 seconds. The exact time can vary based on the generator’s make and model.
3. Warm-Up Period: Some generators might require a brief warm-up period before they can take on the full electrical load. This period ensures that the generator is running smoothly and can handle the demands of your business. The warm-up time is usually very short, around 5-10 seconds.
4. Transfer of Power: After the generator is up and running, the ATS transfers the electrical load from the utility to the generator. This transfer is swift, often taking just a few milliseconds.
5. Continuous Power Supply: Once the transfer is complete, your generator will supply power to your business until the utility power is restored. The ATS will continuously monitor the utility power and automatically transfer back once stable power is detected.

Total Time to Transfer Power from the Utility to a Generator

Duthie Power Services Head of Service, Dewey Brunson, sums it up, “In total, the entire transfer process from the detection of a power outage to the generator supplying power can take anywhere from 10 to 20 seconds.” This duration includes the detection of the outage, the generator’s start-up time, and the transfer of power. While it might seem like a short duration, every second is crucial for businesses that rely on continuous power.

Factors Influencing Transfer Time

Several factors can influence the total transfer time:

1. Generator Type and Model: Different generators have varying start-up times. Modern generators designed for commercial use typically have faster start-up times.
2. Load Requirements: The size and type of load that the generator needs to handle can affect the warm-up period and transfer time.
3. ATS Quality: High-quality ATS units are designed for faster and more reliable performance.
4. Maintenance and Testing: Regular maintenance and testing of both the generator and ATS ensure that they perform optimally during an actual power outage.

Understanding the transfer time of an ATS is crucial for prospective commercial generator owners. While the process is designed to be quick and efficient, knowing the steps involved can help you manage expectations and ensure your business remains operational during power outages. Investing in a high-quality generator and ATS, and maintaining them properly, will minimize downtime and keep your operations running smoothly.

For more information on emergency generator start times, request a quote or give us a call at 1-800-899-3931