Thomas Edison filed a patent application in 1879 depicting the earliest form of the circuit breaker. Edison realized that a surge in current induced by a short circuit could permanently damage electrical equipment , impeding the safe, widespread adoption of electrification.
Short circuits occur because electricity takes the path of least resistance. Even though the power grid delivers electricity at a consistent voltage, the current varies because all powered devices have different loads — how resistant they are to the flowing charge.
Sometimes, a bad connection or faulty wiring allows the current to flow in the wrong direction down an unintended, unsafe route with little to no electrical resistance. This exponentially increases the current flowing through the wire, creating excessive heat. As a result, components may melt, spark or catch fire.
Hugo Stotz, the founder of Stotz and Company, sold his business in 1918 to the Swiss-based Brown, Boveri & Cie (BBC) but remained on board to devote himself to developing electrical products. At the time, expensive, single-use fuses were widely used for circuit protection. Stotz was determined to find a solution to this costly inconvenience.
Stotz and his team created an automatic tripping device using magnetic trip and bimetallic thermal overload functions — the first of its kind. This MCB would switch off when the electrical current became too much. Since it was resettable, users wouldn't have to replace it repeatedly. I patented this design just over 100 years ago, in November 1924.
Decades later, BCC and ASEA of Sweden merged, creating ASEA Brown Boveri (ABB) — a multinational electrical engineering corporation. The company recently celebrated the MCB's milestone 100th anniversary.
MCBs make powering homes and businesses with electricity safer and more convenient. These devices are essential for electrification, making them fundamental to the renewable energy transition.
The world is already transitioning toward clean power. In the United States, renewable generation surpassed nuclear and coal for the first time in 2022. Combined, solar, hydro, biomass and geothermal accounted for about 21% of electric power , outpacing the 20% from coal and the 19% from nuclear.
The closer countries get to a net-zero future, the more important it becomes to make electrification safe and effective. Take solar panels, for instance. Modern models have an energy efficiency rating — the percentage of solar being converted to usable electricity — ranging from 11% to 15%, which is enough to cover the requirements of most commercial or residential buildings.
For solar to replace fossil fuels, it must have a higher energy efficiency rating. The larger the electrical, the more energy management and protection components are needed. This concept extends to renewables like hydro, geothermal and wind energy because variations in supply and demand are common.
While engineers could develop a new technology, MCBs are often the perfect solution. Their versatility, small size, reliability and relatively low production cost make them the ideal protector of electrical circuits.
MCBs are fundamental to the renewable energy transition for several reasons. For one, everything from cars to locks is becoming reliant on electrification. In the past, utility companies, homeowners and business owners were the only ones who needed to worry about safe energy management.
Now, the MCB is an essential part of electric vehicle charging stations, power distribution grids and rooftop solar panels. Low-voltage circuit protection is rapidly becoming an integral part of everyday life, whether people realize it or not.
This adoption surge has been compounded by rapid population growth. Experts predict the number of people on Earth will reach 9.7 billion by 2050. Simply put, the more people there are, the greater the strain on power generation and distribution systems. Circuit breakers must evolve to meet future generations’ power demands and sustainability needs.
Modern circuit breakers will play a central role in safeguarding renewable power sources from electrical overloads and short circuits, ensuring the safety and reliability of clean energy. They may help foster trust in solar, wind and geothermal, streamlining adoption.
MCBs automatically break the internal connection between two wires when voltage levels exceed safe limits, forcing electricity to dissipate safely into the environment instead of damaging hardware. These devices can disconnect the circuit within milliseconds when they detect short circuits or overcurrents.
Resetting a circuit breaker is as easy as flipping a switch — literally. There is no need to replace a fuse or call in a professional.
As demand for renewable electricity grows, engineers must consolidate multiple circuit breakers in a single compartment. Prioritizing organization and efficient electrical distribution is essential.
Since MCBs do not occupy much space, they easily fit into standard electrical panels. Modern versions are even more compact, enabling retrofitting even in decades-old buildings with limited space. This helps keep costs down, facilitating a smoother transition.
The beauty of MCBs is that they are versatile enough for residential, commercial or industrial use. They can protect against electrical damage in almost any low-voltage system. Since this device is standardized, any technological advancements would benefit countless industries.
The MCB is the source of energy management and protection for electric systems. Despite contributing so much to safeguards and technological advancements, it still has room for growth. Further research and development will likely help MCBs become smaller and more efficient, accelerating the transition to clean energy.
