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What Is an Arc Fault Circuit Breaker? – Circuit Breaker Explained

Written by Edwin Jones / Fact checked by Andrew Wright

what is an arc fault circuit breaker

Circuit breakers are vital electrical instruments for our households. They regulate the flow of electricity to our home’s circuitry. They offer protection, preventing the onset of electrical accidents and hazards on our properties.

In more recent times, circuit breakers have been at the forefront of innovation. For example, there has been the invention of various types of electrical breakers. Among them are arc fault breakers.

For people not knowledgeable on all things electricity, a common thought is: what is an arc fault circuit breaker?

To be brief, an arc-fault circuit interrupter is a device that’s used to detect the presence of loose connections in a home’s wiring. Particularly, this type of breaker can differentiate a harmless electrical arc from a dangerous one.

Arc Fault Circuit Breakers Are Used for What


Just like with any regular breaker, they are mostly used to:

  • Regulate electricity
  • Secure the integrity of wire connections
  • Protect your home from unmitigated electrical accidents.

However, aside from the above, arc fault breakers are used to specifically protect establishments, buildings, and occupants from an electrical fire. This is different from the capabilities of regular breakers, which are basically concerned with detecting much higher loads from within electrical lines.

Simply speaking, arc fault circuit breakers are used if you want to upgrade your home’s protection against electrical fires. Because of the sensitive mechanisms within the said breakers, they can capably detect more minute amounts of electrical leaks that could eventually lead to fires.

To upscale your household’s safety, I highly recommend that you install arc fault interrupters in your breaker box. Your electrical code might require their presence, as well.

How Does an Arc Fault Breaker Work

Arc fault circuit breakers work by monitoring the circuit for the presence of “normal” and “hazardous” arcing circumstances.

As electrical arcs are naturally produced by household appliances, such as motorized vacuum cleaners or furnace motors, arc fault breakers must be discerning of nominal and harmful arcing. Another common arcing event occurs when a light switch is turned off, which causes the electrical contacts to loosen, which causes an arc.

Now, these are only some of the common arcing circumstances that arc fault breakers are capable of determining.

To be particular, arc fault breakers work through the use of minuscule filters and logic circuits. These “smart” electrical instruments enable the arc breaker to detect harmful arcing circumstances — when the current alternates at a frequency of about 100kHz.

Now, should irregular arcing occur, the arc fault protection breaker immediately shuts down the concerned circuit. In turn, said breaker prevents the onset of fire.

Difference Between Arc Fault Circuit Interrupter and Ground Fault Circuit Interrupter

Though both of circuit breakers are important to have in households, there are distinct differences between arc fault and ground fault breakers.

GFCIs (Ground Fault Circuit Interrupters) do not have the capacity to detect arcs. Instead, they are used to protect against leakage current and often put in bathroom and laundry areas.

GFCIs work by monitoring the current going to and from an electrical appliance. Once they detect irregularities, these breakers immediately open the circuit, halting the flow of hazardous fault current.

On the other hand, the arc fault breaker requirement for tripping is through the detection of irregular arc electricity within the connection, such as parallel arcing and series arcing.

Nonetheless, the presence of both breakers within your home’s electrical system is beneficial for the promotion of electrical safety.


As arc fault interrupters are relatively niched, learning what is an arc fault circuit breaker can be a substantial addition to your knowledge in all things electricity-related. As you see, arc fault circuit breakers are highly beneficial instruments for your home’s electrical circuit.

All things considered, I can only hope that I have written a succinct explanation regarding this type of breaker. Thanks for reading! If you have any questions, don’t hesitate to comment down below.

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