History of the Circuit Breaker, by Civic Recycling: Part 2

History of the Circuit Breaker, by Civic Recycling: Part 2

We began Part 1 with the inception of the circuit breaker, in Thomas Edison's shop in the 1870s. The Boston Electric Company was the first to manufacture and install a circuit breaker, about 20 years later in 1898. But these early breakers wouldn’t be familiar to you – or to your parents, or even your grandparents.

The First Miniature Circuit Breaker

The miniature circuit breaker you would recognize was born in 1924. A Swiss company called Brown, Boveri & Cie (BBC) patented the design, which was based on an earlier patent by Hugo Stotz. Stotz was an engineer who had founded an electrical society in Mannheim, Germany in 1891. He sold his company and patents to BBC, and they developed and patented the miniature circuit breaker in Germany. Stotz is credited as the inventor, and thus the grandfather of the modern, thermal-magnetic breakers in every home, office, and industrial property today.

Meanwhile, BBC stayed in business under the same name for over 60 years. In 1988, it merged with the General Swedish Electrical Limited Company (ASEA), and became ASEA Brown & Boveri (ABB). ABB still manufactures Stotz circuit breakers, and in 2014 they celebrated the 90-year anniversary of the original patent.

Dangerous Times during the 1900's

During the 1920s, many more buildings became electrified, and more and more electric devices came to the market. In turn, this put an increasing demand on electrical grids. Many electrical lines began to hit amperage levels they weren't designed for. Could be a potential problem right?

In those days, electrifying your home or business wasn't for the faint of heart! Complete short circuits and dangerous fires were common. Even when you decided to cut the power (to avoid a fire), just doing that was a risky task. The only way to cut power was to manually flip an air-brake switch - but watch out for dangerous arcs. The current rarely gave up without a fight!

Something we do not typically think about nowadays. Electricity is pretty safe and those kinds of problems almost unheard of.

More Amperage, more problems?

In 1928, the electrical industry created the first circuit breakers with K characteristics. That means they would trip when the current was 10-14 times the circuit's amp rating. While safer, these early models were too expensive to make their way into most homes or businesses.

Throughout the early 20th century, Stotz's patent was still in force, and BBC remained the primary driving force behind circuit breaker development. But outside of Germany, other companies began developing their own circuit breakers. When BBC’s patent expired in the 1940’s, competition accelerated.

Still, BBC continued to lead the way, and by 1957, they developed a miniature circuit breaker with a full 10 kA rating. This model would trip at a short circuit up to 10,000 amps, protecting most buildings from damage, fire, or worse. By this time, circuit breakers were  starting to look as they do today. However, they remained in their own casing, because they were directly on an individual line, not in a panel.

Introducing Circuit Breaker Panels

At last, the circuit breaker panel came on to the scene in the 1960s. Along with it came the first modular miniature circuit breakers. During the 1960s, lots of North Americans renovated their homes, driving the production of many new circuit breakers. This period saw a wide variety of circuit breaker designs, not all of which proved to be safe.

Through the 1960s, 1970s, and 1980s, electrical service continued to evolve. Beginning in about 1980, many new or renovated homes featured circuit breakers we would consider modern, functional, and safe.


More about breaker manufacturers

Picking up from where the Boston Electric Light Company left off, the circuit breaker was improved then by an inventor by the name of Granville Woods. Around the time that the first commercial circuit breaker was in use, Granville improved the design and invented the automatic circuit breaker. Granville largely focused his efforts on improving and modernizing the railroad business, many of which you can still see in use today.

Post-Granville Woods, the next developments in circuit breaker technology were devised by the Cutter Manufacturing Company. Cutter was the first company to manufacture them on a larger scale, making wide-spread use significantly easier. This product they originally manufactured was known as the ITE Breaker (Inverse Time Element). You will still find versions of the ITE breaker in today’s catalogs, slightly upgraded of course, but the essence of the original is still very much intact.

ITE Breakers & technological advancements

Following Cutter Manufacturing’s advancement of the ITE breaker, there was something of a lull in development. It wasn’t until about the 1920s that specifications for breakers were brought to the fore. What this meant was from that point on those interested in tweaking and making changes to breakers were able to do so with ease. This led to quite a bit of invention and various types of breakers coming and going over the years.


As you probably know, from here, technology flourished and offered us a great many more powerful uses, like the development from the fuse-panel to the circuit breaker panel in homes and buildings. Something that we now take for granted, this was quite the improvement from the ‘60s onward. This change made things significantly easier, as circuit breaker boards could be reset as opposed to fuses that needed to be replaced every time they blew.


Advancements like these, from companies small and large and from people like Granville Woods, have taken us to where we are today. In the final piece, we’ll discuss the future of circuit breakers and their potential uses, as technology becomes a larger and more powerful force in our society. The world is changing quickly and it’s always a fascinating case study on why that is and how business and manufacturers will evolve with it.

Visit us in store or online

We have made some serious improvements as a human species, and we hope to continue the trend! At Civic Recycling, Canada’s number one circuit breaker specialist, we provide open lines of communication at all times. If you have any questions that need to be answered we can always be reached via email at sales@civicrecycling.com, or by phone. Should the purchasing of a new or reconditioned product require our expertise, we’re always happy to answer any questions and to assist in the process.

That’s it for this installment of the history of circuit breakers! Next time we’ll move into the 21st century: a time when our demand for electricity, and the complexity of electrical devices, has reached heights Hugo Stotz could never have imagined.