A Comprehensive Guide To Understanding Your Automatic Transfer Switch A Four-Part Series

A Comprehensive Guide To Understanding Your Automatic Transfer Switch
A Four-Part Series

As part of our ongoing effort to inform and educate our clients, Electro-Motion has created a four-part series on one of the most critical parts of your emergency backup power system: the Automatic Transfer Switch.

So, why is this such an important part of your EPS that it deserves its own four-part series? Imagine having a car but no key for the ignition. Without a functioning automatic transfer switch, your generator is a worthless hunk of metal.

This series is designed to simply but effectively walk you through every aspect of this vital EPS component. From an explanation of the mechanism to the types of preventive maintenance that can extend the life of your unit, you’ll get a comprehensive understanding of how the ATS works and what you can do to ensure its reliability.

Sounds dry and technical? We’ll make sure it isn’t!

In Part 1, we look at the role of an Automatic Transfer Switch in an emergency backup power system to give you a better understanding of why this component is considered the lynchpin of your EPS.

Part 1

In the event of a power outage, especially during critical situations, having a reliable backup power system is essential. Whether it’s in hospitals, financial companies, data centers, or any industry, the seamless transition from the main power source to the backup generator is crucial to maintaining continuity of operations.

At the heart of this transition lies the Automatic Transfer Switch (ATS), a device that plays a pivotal role in ensuring uninterrupted power supply. In this first part of our four-part series, we’ll delve into what an ATS is and why it’s indispensable in emergency backup power systems.

What is an Automatic Transfer Switch (ATS)?

Simply put, an Automatic Transfer Switch is an intelligent device designed to monitor the presence and quality of power from the main utility source and the backup generator. It automatically transfers the electrical load from the main power source to the backup generator during a power outage, and vice versa when the main power is restored. This transition happens seamlessly and swiftly, ensuring uninterrupted power supply to critical systems.

How Does an ATS Work?

The operation of an ATS is driven by sensors that constantly monitor the status of the power sources. When the ATS detects a disruption or loss of power from the main utility grid, it signals the backup generator to start up. Once the generator is up and running and stable, the ATS safely transfers the load from the utility power to the generator power.

Conversely, when the utility power is restored, the ATS senses the return of power and ensures that it’s stable and within acceptable parameters before transferring the load back to the main power source. This automated process eliminates the need for manual intervention, making it a reliable and efficient solution for backup power systems.

Importance of ATS in Emergency Backup Power Systems

Seamless Transition: The primary function of an ATS is to facilitate a seamless transition from the main power grid to the backup generator and back again. This swift transfer ensures that critical systems such as medical equipment, data centers, and security systems remain operational without any interruption.
Protection of Equipment: During a power outage, sudden fluctuations or surges in voltage can damage sensitive electronic equipment. By swiftly transferring the load to a backup generator, the ATS protects equipment from potential damage caused by power fluctuations.

Safety: Manual switching between power sources can be dangerous, especially in hazardous environments or during adverse weather conditions. An ATS eliminates the need for manual intervention, reducing the risk of accidents and ensuring the safety of personnel.

Optimized Energy Management: In situations where backup power is limited, an ATS can prioritize the distribution of power to essential systems, ensuring that critical operations continue to function while non-essential loads are temporarily powered down.

Remote Monitoring and Control: Many modern ATS units are equipped with remote monitoring and control capabilities, allowing operators to monitor the status of the power system and perform diagnostics from a centralized location. This remote accessibility enhances the efficiency of maintenance and troubleshooting tasks.


In emergency backup power systems, the Automatic Transfer Switch serves as a critical link between the main power grid and backup generator, ensuring uninterrupted power supply during outages. Its automated operation and seamless transition capabilities make it an indispensable component of any reliable backup power solution.

So indispensable that your generator will not operate without it.

In Part Two, we’ll discuss the types of Automatic Transfer Switches available and the pros and cons of each type. We’ll also look at the cost of each type, and the impact these switches can have on your business continuity.

In the meantime, if you have any questions, call Electro-Motion at (650) 321-6169, or click here to arrange for a free consultation.

Comments are closed.