Key Differences Between Fuses and Circuit Breakers

Fuses and Circuit Breakers both serve the same purpose – which is to protect electrical circuits by preventing overloads that can cause fires. They both interrupt the flow of electricity, but in very different ways from each other. While a fuse is made of a piece of metal that melts when overheated, circuit breakers on the other hand, have internal switch mechanisms that can be tripped by an unsafe surge of electricity.

Fuses can be quicker for interrupting the flow of power, but when they melt they must be replaced; circuit breakers on the other hand just need to be reset. When comparing the two, we’ll take a look at some of the major advantages and disadvantages between fuses and circuit breakers to distinguish between them.


Fuses come in different types – for both residential and commercial use. The most common type is made from a metal wire or a filament that is enclosed in a glass or ceramic and metal casing. In residential homes, the fuse is usually plugged into a central fuse box, where the building’s wiring passes through. When electricity flows, the fuse will permit the power to pass unobstructed across the filament between circuits. If overloads occur, the filament melts and stops the flow of electricity.


It will take some time for the filament to melt, and therefore any power surge is stopped. When a fuse is blown, it is to be discarded and replaced with a new fuse. There are different voltage and ratings that are available which handle different capacities of electricity. The best fuse for a circuit is usually one that is rated for slightly higher than normal operating current.

Circuit Breakers

Circuit Breakers have two different ways of working – the first is through the use of an electromagnet and the other is through the use of a bi-metal strip. In both instances, when turned on, the breaker allows electrical current to pass from a bottom to an upper terminal across the strip. Once the current reaches any unsafe levels, the magnetic force of the solenoid or strip becomes strong enough to throw a metal lever in the switch mechanism, breaking the current. The other option that can happen is that the metal strip can bend, throwing the switch and breaking the connection.

S-A Q2100

In order to reset the flow of electricity, the switch can just be turned back on. This reconnects the circuit. Circuit breakers in many cases are found in a cabinet of individual switches known as the breaker box. This simple switch action allows for an easy turn-off for individual circuits in a house when needed for working on a wiring in the location.

Circuit breakers have other applications, such as using for ground fault circuit interrupter, or GFCI. The function of this is to prevent electric shock, rather than just overheating. It breaks the circuit in an outlet if the current gets unbalanced. It can be reset by the touch of a button, and is generally useful in kitchens or bathrooms, where electrocution is a risk from the use of electrical appliances near water sources such as sinks or faucets.

Advantages and Disadvantages

Fuses are more inexpensive, available at nearly any hardware store. They react quickly to overloading, offering more protection to sensitive electronic devices. The only problem in this is that if the circuit is prone to surges that regularly cause fuses to blow, then the quick reaction to the overloading can be a disadvantage.

When fuses are blown, they need to be replaced. This can be difficult, especially in a dark room, or if the replacement fuse is not available at the time of need. In many instances, too, people find themselves replacing a fuse with the replacement fuses that actually has a higher voltage or current rating that is too high for the application or need – which can then cause an overheated circuit.

Fuses are generally speaking, easy to see which switch has been tripped, and which would need to be reset. The average homeowner would find it safe since there is no doubt about choosing the right fuse rating and all of the electrical connections are in the breaker box.

The disadvantage to using a circuit breaker is that it can be more expensive to install, repair and replace. Circuit breakers won’t react as quickly as a fuse in power surges. This means it would be possible that electronics connected to the circuit could be damaged by energy that is just let through. It can be more sensitive to vibration and movement, which may allow for a switch to trip for reasons that are unrelated to electricity overloads.

fusebox vs circuit

Circuit breakers and fuses are not interchangeable for all power applications. For instance, a fuse should not be used in situations that require a GFCI. Electricians are best qualified to make decisions on whether a fuse or circuit breaker system is better for any particular instance or scenario or electrical installation. If you have any questions about a particular project and would like to know more, you can talk to an accomplished professional at 1-800-STEINER (783-4637).

18 thoughts on “Key Differences Between Fuses and Circuit Breakers”

  1. my circuit breaker has tripped 3times in the last month. I only have a clock hd box forthe tv inthere. Could the hd box causethat?

    1. Yes. So could a wiring fault or a faulty breaker. I’d recommend swapping breakers with another in your box that is the same rating (amp wise). This will help you indentify a breaker or appliance issue. Just as a warning I am not a electrician just a good trouble shooter/problem solver. If in doubt or if beyond your skill set I’d get an electrician to look at it…

  2. Under Advantages and Disadvantages, paragraph 3, the statements are incorrect! Apparently you interchanged “fuses” and “breakers”. Please check. Thanks

  3. This is a great post about The Differences Between Fuses and Circuit Breakers. We advise if possible to change from fuses to circuit breakers for the simple simplicity of resetting.

  4. While your safety switch will keep you safe by cutting the flow of electricity, it’s still a good idea to take other precautions regardless. When it comes to electricity, there’s no such thing as “too safe”.

  5. Fuses are superior protection. Sometimes fail to trip at their specified rating, becwuse they have a lot of parts. The more parts an electrical device has, the more chance the device will fail to function properly. Your home burns to the ground! The government doesn’t allow use of fuses in medical instruments. The only reason we have breakers in our homes is because idiots would put a penny into a fuse holder, rather than find and correct the overload that caused the fuse to blow.

  6. In some instances a breaker installed in a breaker panel wired to a piece of equipment that has a factory installed fuse of a different or higher rating compared to the breaker feeding it. In such a case what is the breaker protecting and what is the fuse protecting?

    1. Depends on which one has a higher rating. If the fuse is higher than the breaker feeding it, a power event may cause the breaker to switch first (due to a lower energy threshold), ending the connection. If they are very similar in rating, then the fuse would pop first since it is more responsive to surges. But in the case that the fuse is higher, they both can work in a cooperative manner. The fuse can act as a cap to how much energy should come through, as it does take a while for a circuit breaker to react. So if a power surge were to come through a building, the precious seconds a fuse can save is exponential. So all in all, a circuit breaker/fuse combo can be greatly beneficial, as it can preserve your fuse during an amplified but minor electrical event, as your breakers can react, or it can save your house, as the fuse will pop and end the connection if a massive enough surge comes through.

    2. The breaker in the panel protects the wire to the equipment. The fusing inside & installed by manufacturer, is to protect the components inside that equipment.

  7. I found it interesting when you said that the circuit breakers are commonly used to prevent electric shocks. My boss is afraid of getting power outages in the office causing the system to shut down. I will recommend him to contact an electric testing company to come and inspect the whole electric system.

  8. I just switched my 1960 outside breakers from fuses to circuit breaker panel.
    While the ease of use is appreciated the same day after install the utility company had a failure on main line neutral.
    With fuses they would have blown. The circuit breakers tripped, but not before allowing surge to pass through.
    Fortunately I had multi-plug, surge protectors throughout my home that tripped. Two were unrecoverable and needed replacing and two only needed to be reset.
    My surge sensitive electronics such as TVs and laptops were not harmed.
    The ease of problem identification with circuits is the best feature. On the other hand a faulty circuit breaker is a more challenging issue for a homeowner to diagnose.
    I am considering a whole house surge protector on the outside of my home as an added protection.
    Most importantly, remember to label all your circuits to in the breaker box.

  9. Thanks for explaining that circuit breakers work through either an electromagnet or bi-metal strip. I was talking with my sister this morning and learned she’s been having issues with her home’s circuit breaker for the last week or so. I’ll send her this info so she can be more prepared to discuss the issue with an electrician soon!

  10. I’m installing a garage heater 240 volt 8 awg 7500 watts 40 amp breaker two pole,
    I have a federal pacific breaker panel and the breakers are expensive $95 my question is I want to add an extra single box with an additional 40 amp breaker to the same line for safety but most of all to use as a on off switch when not in use is this ok and safe?

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