What Is A Circuit Breaker

Are you facing an electricity surge issue and wonder what you can do to solve the problem? Well, I have got you covered. This article on what is a circuit breaker will be helpful for such an issue.

Many times, there can be either high current or low current in our residence, which affects the appliances in the house. This can damage these appliances and lead to a fire outbreak if one is not careful.

Take a look at my article on What is a circuit breaker which you will find helpful. First, however, this article will discuss what a circuit breaker is and its benefits.

I will also give a guide on how it works. Now let’s dive into What is a circuit breaker.

Circuit Breaker Explained.

What Is A Circuit Breaker

A circuit breaker also called a trip switch – is an electrical switch protecting an electrical circuit from overcurrent/overload or short circuits. Looking at this definition, what now comes to mind is what is an electrical circuit, overcurrent, and short circuits.

An electrical circuit is simply a closed path for the flow of electrical current. At the same time, an overcurrent in an electrical circuit is when the current load exceeds the average level.

Also, an overload is when one draws a high amount of electricity more than a circuit can handle. Finally, a short circuit happens when an electrical current flows on the wrong path without electrical resistance.

Hence, the trip switch obstructs the electric current flow to protect the electrical system from damage. Its function is to protect the electrical circuit from damage.

The circuit breaker interrupts the flow of current when the protective relay detects a fault. It also trips automatically when it detects a fault.

By trip, I mean it shuts off the electricity flow in the electrical circuit. Hence, the circuit breaker serves as a regulatory device.

Also, there are different types of circuit breakers. Thus, these types are based on classifications.

These classifications include voltage, installation process, exterior design, and interrupting mechanism. However, people confuse circuit breakers with fuses.

Although, both circuit breaker and fuse perform the same function of preventing the high flow of electrical current from damaging the electrical circuit. Nevertheless, they perform these functions in different ways.

A circuit breaker consists of various parts that make it up, and they are five in number. They include frame, operating mechanism, contacts, air extinguisher, and trip unit.

The frame protects the inner parts of the circuit breaker from the outer parts. At the same time, the operating mechanism allows the means of opening and closing the circuit breaker.

Also, contacts let the current flow through the circuit breaker while it is closed. For arc extinguisher, it helps to disrupt an arch when the circuit breaker obstructs a fault.

Lastly, trip units open the operating mechanism when an overload or short circuit incident continues.

Benefits Of A Trip Switch

Benefits Of A Trip Switch

One thing that people bear in mind is what do I stand to gain from using a trip switch? So here, I will be highlighting the benefit of these trip switches.

1. Circuit breakers are reliable. It protects the electrical system and the entire house from damage, making it authentic.

2. A trip switch is very sensitive, making it quick to detect faults in the electrical circuit.

3. The trip switch also automatically retains its connections, making the circuit start operating again.

4. The trip switch is easy to operate and proves to be safe for the operation of an electrical circuit.

5. Circuit breakers have a switch that can reset as it operates.

6. A trip switch is convenient and economical, and thus makes it a beneficial device that protects our electrical equipment or appliances and even the entire house.

How Does A Circuit Breaker Works?

HoDoes A Circuit Breaker Works_

First, the circuit breaker must discover a fault in the electrical circuit. After this, the circuit breaker contacts will open to obstruct the circuit.

These metallic contacts are made of highly conductive materials like copper or copper alloy. It has both fixed and moving contacts with an operating coil. In a closed circuit, these contacts touch themselves, allowing electricity flow.

Though, the contacts opening is possible due to the mechanical pressure applied by a spring or compressed air to disconnect the contacts. Also, it can use high currents such as thermal expansion or a magnetic field created by the fault to separate the contacts.

However, small circuit breakers have a manual control lever to switch off the load or reset a tripped switch. In the case of a large trip switch, it uses solenoids to trip the mechanism and electric motors to restore energy to the springs.

Solenoids are cylindrical coils of wire that act like a magnet when it carries electric current. After that, the contacts will carry the load current without extreme heat.

The contacts would also withstand the arc’s heat produced while opening the circuit.

However, to understand how a circuit breaker works, you can read more on “how a circuit breaker works.” 

Arc Explained

When there is an obstruction in a high voltage or current, it produces something we refer to as an arc. Thus, an arc length is proportional to the voltage, while the heat is proportional to the current.

It is essential for the arc to be kept under control by cooling and quenching it. The result is that the gap between the trip switch contact can resist the voltage in the circuit again.

Lastly, once the fault condition restores, the contacts will close again to restore power to the interrupted circuit.

Circuit Breaker Vs Fuse

Circuit Breaker Vs Fuse

As I said earlier, the circuit breaker and fuse perform the same functions but differently. A fuse melts when it overheats to stop the flow of electrical current, whereas a circuit breaker has a switch inside that stops the current when there is a surge in electricity.

However, a circuit breaker automatically disconnects the connection of the power load whenever it exceeds supply, which prevents fire and other problems on the device connected. In comparison, a fuse prevents the device from damage if the current exceeds the required amount.

Since the circuit breaker trips and disconnects from the device connected automatically, it makes it reusable, unlike a fuse that melts when the current exceeds the required amount.

The trip switch uses an electromagnetic mechanism to switch off the connection based on its operation principle. At the same time, a fuse uses conductive materials that have electrical and thermal properties that can damage easily.

A trip switch can operate automatically and manually in its operation mode. The fuse, however, works automatically though you need to re-fix it.

Circuit breakers protect the entire apartment than the electronic devices separately. At the same time, fuses protect the devices in the house than the whole apartment.

In the same vein, a trip switch protects homes and devices from overload and short-circuiting. In contrast, a fuse protects the home appliances from excesses alone.

Types Of Circuit breaker/ Trip Switch

There are various types of circuit breakers, and these types are based on different classifications. However, these classifications include voltage, installation location, external design, and interrupting mechanism.

Voltage Explained

There are two types of circuit breakers based on voltage: low voltage and high voltage circuit breakers.

The low voltage trip switch measures low voltage up to 2kV. Small-scale industries mostly use this type of circuit breaker.

On the other hand, the high voltage measures the use of voltages more than 2kV. So we can further divide it into transmission breakers which rate 123kV and above, and a medium voltage lesser than 72 kV.

Installation Location Explained

There are two types under this: indoor and outdoor circuit breakers.

The indoor circuit breaker is used inside buildings or weather-resistant areas. It operates at a medium voltage with a metal cover switchgear enclosure.

The outdoor circuit breaker is used outside without any roof. Instead, it has an external enclosure that makes it strong and can endure wear and tear.

External Design Explained

However, based on the external design, there are two types: dead tank and live tank circuit breaker.

The dead tank circuit breaker is a switch with a tank at a potential on the ground. This tank encloses all the insulating and interrupting mediums.

On the other hand, the live tank circuit breaker is a switch with a tank that houses the interrupter at a potential above the ground. This tank is above the ground with the insulator medium in between.

Interrupting Mechanism Explained

Various types will be explained under the classification based on the interrupting mechanism.

Air Circuit Breaker explained

First, the Air circuit breaker uses air to insulate and interrupt. Then, this breaker is further divided into low voltage below 1000V and a high voltage whose rate is 1000V and above.

The air circuit breaker is divided into two; plain and airblast circuit breaker.

The plain circuit breaker is preferable for low voltage use. This breaker is fixed with an arch chute that surrounds the contacts. This arc chute is simply a chamber in which an arc is in it.

The arc chute helps in the cooling of the air circuit breaker. The walls inside the arc chute have a shape that is not forced to close.

The air blast circuit breaker is preferable for 245kV, 420kV and more system voltages. It has two types; axial blast breaker, where moving contact will be in contact, and axial blast with sliding moving contact.

Oil Circuit Breaker Explained

The oil circuit breaker is the oldest type of circuit breaker. This breaker uses oil, preferably mineral oil, as a medium for insulating and interrupting.

When the current separation happens, the carrier then contacts the oil. Therefore, the arc in the circuit breaker simultaneously activates the separation of contacts.

This is because the arc in the oil vaporizes and decomposes in hydrogen gas, creating a bubble around the arc.

This is because it prevents re-striking of the arc after the current reaches zero crossings of the cycle. However, it has two types; bulk oil and minimum oil circuit breaker.

Bulk oil circuit breaker uses oil as a medium for quenching and insulating the arc in-between the earth parts of the circuit breaker and current-carrying contacts. This breaker uses the same oil for insulating a transformer.

Minimum oil circuit breaker uses oil as an interrupting medium. This breaker places the interrupting unit in an insulating chamber at the live potential.

However, the insulating material is found in the interrupting chamber. Thus it needs less amount of oil.

Vacuum Circuit Breaker Explained

The vacuum Circuit Breaker uses the vacuum as an interrupting medium because it has high dielectric and diffusive properties. This breaker uses the vacuum to extinguish the arc.

This breaker interrupts high-frequency currents caused by arc instability underlying the line frequency current.

Miniature Circuit Breaker

Miniature circuit breaker uses an electromechanical device. That is, it makes use of an automatic switch. This breaker has a current rating of less than 100A and has only one over-current protection built inside it.

Meanwhile, the trip settings in this breaker are not adjustable.

Molded Case Circuit Breaker

Molded case circuit breaker uses also uses an electromechanical or thermal-magnetic device; that is, it uses an automatic switch. This breaker has a current rating higher than 1000A and has fault protection with current protection.

Also, the trip setting in this breaker is easily adjustable.

Standard Circuit Breaker

The standard circuit breaker has two types: single pole and double pole circuit breaker.

The single-pole circuit breaker is a type that has one hot wire and one neutral wire which operates at 120V. Hence, the circuit breaker interrupts only the hot wire when a fault occurs.

The double pole circuit breaker has two hot wires, which operate at 220V. However, the two poles need to be interrupted when there is a fault.

How To Install A Circuit Breaker/Trip Switch.

How To Install A Circuit Breaker_Trip Switch.

To install a trip switch, one needs to understand the layout of the electrical panel and take adequate precautions during the installation process. Here are the steps to install a trip switch.

 Where to Install the Circuit Breaker/ Trip Switch .

The first step here is turning off the electrical panel’s power supply. However, on the panel, you will see either the Service Disconnect or Main breaker, locate it, and place it to the “off” position.

This is located at either the top or the bottom of the panel.

The next step is to carefully inspect the breaker arrangement for places that have not been used. To do this, you need to look for blank spaces on the panel that can house the trip switch.

Thus, you can focus on the spaces at the top or bottom of the panel. Sometimes, these panels usually have a removable knockout plate.

You need to remove the knockout plate on the used space before proceeding with the installation process. After this, you need to identify the space to install the trip switch.

The next thing is to carefully remove the panel cover. To do this, you will use a screwdriver to unscrew three of the screw holding the cover.

However, to remove the last screw, you need to use one of your arms to hold the panel cover while removing the screw. Then you can remove the cover away from the panel.

After this, you need to test the panel to ensure the power is off. To do this, you will need a testing light or meter set to check if there is still current in the panel.

Testing is important because it is unsafe to continue the installation process if electricity flows. So you need to make sure you disconnect from the main power source.

Next is to place the new circuit breaker next to the circuit breaker still in use. You need to compare the new location to that of the earlier removal cover to ensure it aligns properly.

Placing the Circuit Breaker on the panel

The first thing here is to make sure you have the correct circuit breaker. Then, you’ll find a label that lists the types of panels that you can install on the panel.

To avoid damages, you need to use the same configuration as the old circuit breaker. Also, the trip switch should have an ampacity that does not surpass the circuit conductor’s rating.

The next thing to do is set the breaker to the off position before installing it for your safety. After this, you need to align the circuit breaker with the bar in the panel.

However, you need to tilt the breaker so that the clip at the bottom will attach the plastic grab bar to the panel. In addition, you may need to apply pressure for it to attach the bar.

Next, is to use your thumb to press the breaker firmly but gently to sit on the bus bar. You need to press it until it snaps into place on the bus bar.

The last thing here is to connect the circuit wiring to the panel. This is done by connecting the white neutral wire and the black hot wire to the breaker.

The connection should only be made after ensuring that the breaker is in the off position.

Finishing and Testing the Installation

The first thing here is that you need to remove the knockout plate from the cover. To do this, you need a plier to remove the knockout plate from the cover after locating the trip switch.

After this, you need to remove any tools, wire scraps, or anything that can cause a short circuit from the inside of the panel. You can now place the cover on the panel to check if the trip switch sits well and fits through the cover.

Then you can now screw back the cover to the panel.

The next step is to activate the main switch and test the new circuit breaker. To do this, stand to one side of the panel and turn the service disconnect or main switch to On to restore power.

Also, you need to set the new circuit breaker to On. Eventually, you need a test light or a meter to check if the new circuit breaker is working correctly.

Lastly, you need to label the trip switch. To do this, you need to look for the panel’s circuit directory inside the panel’s door.

After that, you will determine the circuit breaker location or circuit number and then write the description of the circuit in the space provided

Furthermore, you can get a more vivid explanation of the installation process on How to Install a Circuit Breaker. 

What To Consider When Choosing A Circuit Breaker/ Trip Switch

Indeed, when you want to purchase a trip switch, there is a number of factors to consider. Whether you are purchasing a commercial or a residential trip switch, these factors are applicable.

Here are the factors to consider.

The first thing to consider is the voltage load. The voltage load depends on where the trip switch is to be used, either a commercial or industrial area or a residential area.

Moreover, this is because of the amount of electricity that flows through the circuit. Therefore, a large piece of equipment requires a high voltage trip switch because it uses a large amount of power or electricity.

It is also important to know the purpose of the trip switch you purchase.

A low Voltage trip switch takes loads of up to 1000 volts without any issue. This type should be considered for residential use.

A Medium Voltage trip switch takes loads between 1000 volts to 72000 volts. This type is suitable for a commercial office building, and a residence that uses a high voltage tool can also use it.

A high voltage trip switch takes loads of 72000volts and above. This type is suitable for industrial and commercial use because they make use of large equipment.

The next thing to consider is the amperage of the trip switch. Again, the trip switch operates at 100% of the load it requires.

However, you should choose a trip switch that operates approximately 120% of the load it requires. This is because a higher amperage helps to reduce the heat generation in the power system.

Another thing to consider is the type of trip unit. There are several types: magnetic, thermal, thermal-magnetic, and magnetic hydraulic trip units. 

Also, another thing to consider is the temperature operating range of the trip switch. Hence, circuit breakers operate at different temperatures, and this should be a consideration.

Pros And Cons

Here, I will give the advantages as well as the disadvantages of a circuit breaker.


  1. A circuit breaker protects the electrical system from damage that by the excessive flow of current.
  2. It is easy for a user to reset. This is because it operates through a switch; unlike the fuse that needs a spare
  3. circuit, breakers are quite sensitive because they detect faults quickly.
  4. The circuit breaker is very reliable because it adequately protects the electrical system from damage
  5. it is very portable and small in size, unlike the fuse.
  6. You can adjust the trip curve to suit the circuit design with electronic trips.
  7. Circuit breakers are reusable.


  1. Circuit breakers are more expensive in terms of installation and repair, unlike fuses.
  2. Fuse reacts faster when it detects a fault, unlike circuit breaker. It is hard to coordinate fault selectivity.
  3. When trips occur, it affects all the power, unlike a fuse where it affects only that phase.
  4. When there is a problem with the switch system, the circuit breaker will not be able to trip.

Recommendation; What Is a Circuit Breaker?

Recommendation; What Is a Circuit Breaker_

Here is my recommendation on the best circuit breaker in the market.

Siemens Q220_3PK 20 Amp Double Pole Type QP Circuit Breaker (Pack of 3)

The Siemens type QP circuit breaker has a size of 20 amps with a plug-in mounting style. This circuit breaker makes use of two poles.

This switch protects your electrical system from overload and short circuits. This breaker also provides easy plug connections in Siemens enclosures.

The Siemens-type QP circuit breaker also features a time-saving insta-wire. However, it is compatible with Siemens PL and ES series load centers.

Also, this breaker is intended for 220/240-volt usage.

T Tocas 32v DC Circuit Breaker Fuse Inverter with Manual Reset Button Switch Fuses 12V 15A.

The T Tocas DC circuit breaker has a current rating of 15 amps with 32 volts. This breaker is a single pole with a panel mount style.

This switch combines both switching and circuit protection into a single device. It also has a manual reset which makes it switchable.

The T Tocas DC circuit breaker has BAT LINE SHI for input wire and AUX LOAD for output wire. Also, it is easy to install.

This breaker has ignition protection. This means it will not normally spark that, which will lead to a possible explosion of flammable vapors.

Also, it has an interrupting capacity of 2500A @ 14Vdc.

Q115 15-Amp Single Pole Type QP Circuit Breaker

This circuit breaker is a brand of Siemens with a circuit breaker type QP. This breaker has a current rating of 15 amps with 120 volts.

It is a single-pole with a plug-in mount style. This switch also protects electrical systems from overload and short circuits.

This breaker is also compatible with Siemens PL and ES series load centers. It has an interrupting rating of 10,000 AIC.

Square D Homeline HOM250 Miniature Circuit Breaker, 120/240 VAC, 50 A, 10 kA, 2 Poles, Thermal Magnetic Trip

The Square D miniature homeline circuit breaker is a product of Schneider Electric with a Square D brand. It has a current rating of 50 amps with 120/240 volts.

This breaker is a two-pole with a plug-in mount type. It also has an interrupter of 10kA.

The Square D miniature homeline circuit breaker also has a thermal-magnetic trip and is wired electrically.

Nilight 90101E 5Gang Multi-Function 5 Gang Rocker Dual USB Charger + Digital Voltmeter +12V Outlet Pre-Wired Switch Panel with Circuit Breakers for RV Car Boat Truck Trailer,2 Years Warranty

The Nilight Multi-Functional 5 Gang Switch Panel circuit breaker is a panel-mount style with a push on a terminal. This circuit breaker is integrated with a dual USB port with a digital voltmeter.

It has a waterproof board and 5 on/off switches. It also has a 12/24V electrical panel that can suit various needs.

This switch has prewired design with a 15A fuse that provides an overload, over-current, and short circuit protection. It also has a real-time LED voltmeter that shows the status of the voltage.

The Nilight Multi-functional 5 gang switch panel circuit breaker has a switch suitable for 12V-24V systems. It is convenient to install with prewired and four assembled screws.

My Conclusion; What Is A Circuit Breaker?

My Conclusion; What Is A Circuit Breaker_

Many times, electric voltage and current have become unpredictable and can lead to damage to our electrical equipment. Also, this can eventually lead to a fire if one is not careful.

The invention of circuit breakers helps to solve this issue. Circuit breakers protect our homes, offices, and even industries from any sudden electrical surge.

The circuit breaker is the most common device used for overcurrent protection in high-current circuits today.

Even though the installation and repair seem expensive, circuit breakers have proved to be very efficient and have excellent performance.

However, I have recommended a series of circuit breakers above. A buyer can choose the one that can best suit their needs.

I hope you found this PowerVersity pick helpful?

If you found it helpful, kindly share your thoughts with the “Leave a Reply” form found towards the end of this page.

Finally, you may want to read other articles like this. Visit our below pages.

5 Best Circuit Breaker

How Does a Circuit Breaker Work?

Oreoluwa Falujo
Oreoluwa Falujo
Oreoluwa Falujo is a Lead Content Editor at PowerVersity.com. She has a bachelor's degree in political science. She likes to watch movies, play games, and listen to music. At PowerVersity.com, Oreoluwa writes buyer guide articles, best picks, and technology-explained articles. She also leads a content writing team.


What is an Electric Hot Plate

What Is An Electric Hot Plate?

Are you looking for a fast and convenient way to cook and probably thinking of how to get the best electric cooking plate? Then,...
5 Best 43-Inch TVs

5 Best 43-Inch TVs

Do you want the best budget TVs that offer great value for their price? Then, continue reading this article on the 5 Best 43-Inch...
5 Best 13x19 Photo Printer

5 Best 13×19 Photo Printer

Are you a photographer looking for a high-quality photo printer? Then, take your time to read through this article on the "5 Best 13x19...
What Is Solar Power Solar Energy Systems

What Is Solar Power: Solar Energy Systems

Are you willing to broaden your knowledge of what solar power is? Then, explore this Powerversity article to clear your curiosity and increase your...

By using this website you agree to accept our Privacy Policy