AFCI circuit breakers: What are they and how can you use them?

The AFCI circuit breaker is considered to be one of the greatest inventions for keeping your home safe. It functions as a power block that identifies the hot spots within an electrical circuit.

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What is an AFCI breaker?

This device is designed to turn off the power in the event of an unintentional arcing fault that occurs when current flows through an unplanned path. The resulting arc produces intense heat, which can cause smoldering particles to ignite surrounding materials like wood structures or insulation. The temperature of these particles can reach in excess of 10,000 degrees Fahrenheit.

What circuits need AFCI breakers?

The 2008 NEC (National Electric Code) requires combined AFCIs on all residential 15- and 20-amp circuits, with the exception of laundry rooms, kitchens, bathrooms, garages, and unfinished basements, although many of these require GFCI protection.

The 2014 NEC added kitchens and laundry rooms to the list of rooms requiring AFCI circuits, as well as any devices (such as lighting) that require protection.

What is a combination AFCI circuit breaker?

A combination AFCI (Arc Fault Circuit Interrupter) circuit breaker is a device that combines the functions of a regular circuit breaker and an AFCI. It provides protection against both overloading and over-currents, as well as against electrical arcs that can cause fires. The AFCI feature monitors the electrical current in a circuit and detects any unusual arcing conditions, which are indicative of a potential fire hazard. If an arc is detected, the combination AFCI breaker will trip and shut off power to the circuit, thereby preventing a fire from starting.

What is the difference between GFCI and AFCI?

GFCI (Ground Fault Circuit Interrupter) and AFCI (Arc Fault Circuit Interrupter) are two different types of electrical safety devices.

A GFCI protects against ground faults, which are caused by current leaks to the ground and can result in serious injury or death. A GFCI works by constantly monitoring the balance of current going to and returning from an electrical device. If it detects an imbalance, indicating a ground fault, it trips and interrupts power to the device.

An AFCI, on the other hand, protects against dangerous electrical arcs, which can cause fires. An AFCI works by constantly monitoring the electrical current in a circuit and detecting any unusual arcing conditions, which are indicative of a potential fire hazard. If an arc is detected, the AFCI trips and interrupts power to the circuit.

In summary, a GFCI protects people from electrical shock, while an AFCI protects against electrical fires.

How does an AFCI work?

AFCIs use electronic sensing circuitry to distinguish between good and bad arcing conditions. When it detects an undesirable arcing condition, the AFCI control circuitry trips the internal contacts, removing power to the circuit and reducing the possibility of a fire.

Methods for detecting “faulty” arcs include observing certain frequencies, discontinuities, and inconsistencies in the current waveform. For detection, both the magnitude and duration of a given half-cycle are required. Some detection algorithms also take into account the rising or falling edges of an arc current for their detection criteria. The voluntary industry standard for AFCIs requires a trip if 8 arc half-cycles occur within a 0.5-second interval.

AFCI/GFCI dual-function circuit breaker

A dual-function AFCI/GFCI circuit breaker is a device that combines the functions of both an AFCI (Arc Fault Circuit Interrupter) and a GFCI (Ground Fault Circuit Interrupter) in one unit. This type of breaker provides protection against both electrical arcs that can cause fires, as well as ground faults, which can result in electrical shock.

AFCI protection monitors the electrical current in a circuit and detects any unusual arcing conditions, which are indicative of a potential fire hazard. If an arc is detected, the breaker trips and shuts off power to the circuit.

GFCI protection works by constantly monitoring the balance of current going to and returning from an electrical device. If it detects an imbalance, indicating a ground fault, it trips and interrupts power to the device.

Having a dual-function AFCI/GFCI breaker can provide additional safety and peace of mind for homeowners, as it offers protection against both electrical fires and shock hazards in one compact unit. However, it is important to consult with a licensed electrician to determine the specific needs of the home and ensure that the appropriate type of breaker is selected.

Are AFCI breakers really necessary?

Whether AFCI breakers are necessary or not depends on various factors and personal preferences. Here are some points to consider:

Safety

AFCI breakers provide an extra layer of protection against electrical fires, which can be a significant hazard in the home. The National Fire Protection Association (NFPA) recommends the use of AFCI protection in areas of the home where electrical arcing hazards may exist.

Code requirements

The use of AFCI protection may be required by local building codes, especially for new construction or remodels. Building codes are designed to ensure that homes are safe and up to standards.

Peace of mind

Having an AFCI breaker can give homeowners peace of mind knowing that their home is protected against electrical fires.

Ultimately, whether or not to use AFCI breakers is a decision that should be made in consultation with a licensed electrician and based on personal preferences, local building codes, and the specific needs of the home.

AFCI breakers recommendations

AFCI circuit breakers are reliable, effective, and the most economical fire insurance that can exist in your home.

It is recommended to replace existing circuit breakers with arc-fault circuit interrupters, even if they are not doing anything that requires inspection. It only takes a few minutes. If you’re not sure how to do it safely, consult a licensed electrician.

It’s worth making the investment and switching, even if that costs you a little money upfront. The insurance it provides makes it worth the small investment.

Arc-fault circuit breakers are the safest and most economical invention you have to prevent fires in the home. Remember that one of the main causes of annual fires is hot spots in electrical circuits. This device combined with the action of a GFCI gives you complete safety as far as electrical circuits are concerned.

Written by Vanessa Gallanti. February 24, 2023

Enthusiast about planning, project management, construction materials and technology, and construction. A civil engineer from Los Andes University and a content writer for Kukun.