how to change a circuit breaker fuse


Why Should You Learn How to Change a Circuit Breaker Fuse?

If you are a homeowner or a renter, understanding the basics of your home's electrical system is essential. Knowing how to properly change a circuit breaker fuse is not only a useful skill but also a crucial one. Fuses are designed to protect electrical circuits from overloading, and when a fuse blows, it needs to be replaced promptly. Hiring an electrician to replace a fuse every time it blows can be costly and inconvenient, especially if it happens frequently. By learning to change a circuit breaker fuse on your own, you can save both time and money, and have the necessary knowledge to handle this common electrical issue.

How Does a Circuit Breaker Fuse Work?

Before diving into the process of changing a circuit breaker fuse, it is important to understand how it works. A circuit breaker fuse is essentially a switches that prevents excessive current flow in an electrical circuit. It serves as a safety measure to protect both the wiring and the electrical devices connected to the circuit. When the current exceeds a certain level, the fuse will blow and interrupt the circuit, preventing further damage or potential hazards.

Understanding the Different Types of Fuses

There are several types of circuit breaker fuses, and understanding their differences is essential before you attempt to change one. The most common types include:

1. Standard Fuses: These fuses are often found in older homes and have a screw-in design. They are typically made of glass or ceramic and come in different amperage ratings. Standard fuses can be more challenging to find and replace since they are becoming less common.

2. Cartridge Fuses: Cartridge fuses are cylindrical in shape and have metal end caps. They are commonly used in modern homes and are available in both time-delay and fast-acting versions. Cartridge fuses are usually easier to find and replace.

3. Plug Fuses: Plug fuses are commonly found in residential fuse boxes and have a screw-in design. They come in various amperage ratings, and some even feature a built-in indicator that shows whether the fuse has blown or not.

4. Miniature Circuit Breakers (MCBs): MCBs are similar to traditional circuit breakers but are often used as replacements for fuses. They have a switch-like appearance and offer better protection against short circuits and overloads. MCBs are commonly found in modern homes and can be easily reset after tripping.

Each type of fuse has its own characteristics and requires specific steps for replacement. Therefore, it is essential to identify the type of fuse you have before attempting to replace it.

Gathering the Necessary Tools and Materials

Before you begin changing a circuit breaker fuse, it is important to gather all the necessary tools and materials. Here are the items you will need:

1. Replacement Fuses or MCBs: Depending on the type of fuse you have, make sure to have an adequate supply of replacement fuses or MCBs on hand. It is recommended to have a few spares in case of future emergencies.

2. Screwdriver: A screwdriver will be used to remove the panel covering the fuse box and possibly to loosen the fuse itself. Depending on the fuse type, you may need either a flathead or a Phillips screwdriver.

3. Flashlight: Since fuse boxes are often located in dimly lit areas such as basements or utility rooms, a flashlight will help you see clearly and safely during the replacement process.

4. Rubber Gloves and Safety Glasses: Electrical safety should always be a priority. Wearing rubber gloves and safety glasses will protect you from any potential electric shock or debris while working with the fuse box.

5. Circuit Tester: A circuit tester is a handy tool to determine whether the circuit is live or not. It will help ensure your safety by indicating whether the power has been successfully cut off before starting the replacement process.

Now that you have gathered all the necessary tools and materials, it's time to proceed with changing the circuit breaker fuse.

Changing a Circuit Breaker Fuse Step-by-Step

1. Identify the Faulty Circuit

Before you can change the circuit breaker fuse, it is crucial to identify the faulty circuit. In most cases, a blown fuse will cause a loss of power in specific areas of your home. Begin by checking which lights or outlets are no longer functioning. Once you have located the affected circuit, turn off all the electrical devices connected to it.

2. Locate the Fuse Box

The fuse box, also known as the electrical service panel, is usually located in a basement, utility room, or garage. It is a metal box that contains all the fuses or circuit breakers for your home's electrical system. Use your flashlight to ensure proper visibility in the area.

3. Turn Off the Main Power Supply

To ensure your safety, it is important to turn off the main power supply before working on the fuse box. Locate the main switch or breaker, usually positioned at the top or bottom of the electrical panel, and switch it off. This will cut off the power supply to the entire house, including the fuse box.

4. Remove the Fuse Box Cover

Once the power is completely cut off, you can safely remove the fuse box cover. Depending on the type of fuse box, you may need to unscrew some screws or use a latch to release the cover. Be cautious as the cover may be heavy or difficult to remove.

5. Identify the Blown Fuse

Using your flashlight, carefully inspect each fuse to identify the blown one. A blown fuse may have a visible break in the metal strip inside it or a blackened appearance. If you are unsure which fuse is blown, you can use a circuit tester to ensure accuracy. Touch the circuit tester's leads to the metal ends of each fuse. The fuse that does not produce a reading indicates a blown fuse.

6. Remove the Blown Fuse

With the blown fuse identified, use a screwdriver to carefully unscrew or loosen it. Grip the fuse firmly and pull it out of its socket. It is important to handle the fuse by its insulated portion to avoid electrical shocks.

7. Insert the Replacement Fuse

Take a new fuse of the same type and amperage rating as the blown one and insert it into the empty socket. Make sure the fuse is pushed all the way in until it is properly seated.

8. Replace the Fuse Box Cover

Once the replacement fuse is securely in place, it is time to put the fuse box cover back on. Align the cover with the box and fasten any screws or latches to secure it. Make sure the cover is properly closed.

9. Restore the Power Supply

Now that you have successfully changed the blown fuse, it's time to restore the power supply. Return to the main power supply switch or breaker and turn it back on. This will reactivate the electricity in the entire house, including the newly replaced fuse.


Changing a circuit breaker fuse is a necessary skill for any homeowner or renter. By understanding how fuses work, identifying the different types, and following a step-by-step process, you can confidently replace blown fuses without relying on expensive professional help. Remember to always prioritize safety by wearing protective gear, turning off the main power supply, and using the proper tools. With practice, changing a circuit breaker fuse will become second nature, allowing you to quickly restore power to your home.


Just tell us your requirements, we can do more than you can imagine.
Send your inquiry

Send your inquiry

Choose a different language
Current language:English