Loose electrical connections, damaged wires, and deteriorated devices are among hidden fire hazards in both residential and commercial properties. While conventional circuit breakers are great at addressing potential risks from short circuits and overloads, they fall short when it comes to detecting and protecting against arc faults. This is where an arc fault breaker comes in handy.
What is an arc fault breaker and how does it work? In this comprehensive guide, we break down the innovative technology behind this protective device and help you understand its use in minimizing potential electrical risks.
Understanding the Arc Fault
In order to understand what an arc fault breaker is, we first need to take a look at the term arcing and the term ‘arc fault.’ Arcing refers to an electrical phenomenon whereby an electric current flows through the air or any other medium connecting two conducive points. When this happens, the current might create an invisible electric discharge or a spark that might not trigger a standard circuit breaker.
The phenomenon typically occurs when there is a breakdown in an electric circuit. You might have heard arcing in action from a buzzing electric outlet or a hissing light switch. An arc fault refers to the electrical hazard that results from arcing.
Causes of Arc Fault
Some of the factors that can contribute to the creation of an arc fault include:
- Damaged wires resulting from improper installation.
- Loose connections that create small gaps.
- Electrical cords that are stressed due to bending, twisting, coiling, or being trapped by furniture.
- An insulation gap resulting from screws, nails, or staple pins being inadvertently driven into wiring.
- Natural wear and tear of electrical components or systems
Whenever electric current flows through a path with any of these issues, an arc fault might occur. In some cases, the fault results in the generation of high heat levels that can ignite the insulation or other materials close to the outlet.
Differentiating Arc Faults, Ground Faults, and Short Circuit
Though the above terms are often used interchangeably, they have distinct differences and require different preventive measures. Let us take a closer look:
Arc Fault vs. Ground Fault
While both of these are electrical faults, they differ in a number of ways. As discussed above, an arc fault results from a gap in an electric circuit, which can generate sparks or arcs and potentially cause an electrical fire.
On the other hand, a ground fault happens when an electric current uses a path other than the intended circuit to come into contact with the ground. In some cases, a live wire comes into contact with an unearthed surface or a grounded part of an electric system. This typically results from a wiring fault, water intrusion or damaged plugs and appliance cords and poses a serious risk of electrocution or shock.
Arc Fault vs. Short Circuit
A short circuit is a broad term describing a situation where an electric current finds a way out of the required wiring system and creates contact with the grounding or neutral wiring pathway. When it bypasses the intended path, resistance drops to a very low level and the current volume surges. Without the correct protective system, this can result in overheating, generate sparks, and even cause an explosion.
Protective Devices
As is clear from the above, the nature of faults causing these phenomena is vastly different. By extension, the protection devices used to mitigate their risks also differs.
To protect against an arc fault, you require an arc fault breaker, also known as an Arc Fault Circuit Interrupter (AFCI). Ground Fault Circuit Interrupters (GFCIs) protect against ground faults while circuit breakers and fuses protect against short circuits.
Differences Between AFCI Outlets and Arc Fault Circuit Breakers
AFCIs fall into two main categories, AFCI outlets and AFCI circuit breakers. Both types of protective devices are designed to offer protection against electrical fires by detecting arc faults and interrupting them. However, an AFCI circuit breaker or arc fault breaker provides more comprehensive protection.
It is installed in place of a standard circuit breaker in the electrical distribution panel. It therefore protects the entire circuit, including the circuit breaker panel, connected devices, outlets and lighting fixtures within the circuit. Because it needs to be connected to the main electrical panel, it is often installed by a certified electrician.
An AFCI outlet is installed on a specific outlet, providing protection to all appliances and devices plugged into it. It resembles a regular outlet but incorporates specialized technology to detect arc faults. Since it can be installed in any part of the house, it is a suitable solution for older constructions where upgrading the entire main panel is impractical.
How Does an Arc Fault Breaker Work?
Here is how an AFCI breaker works to provide safety against arcing:
Detection
The device has advanced electronic components that monitor the flow of electrical current in a circuit. They use digital signal processing to differentiate between benign arcing and dangerous arcing that can pose a fire hazard.
Benign or normal arcing often happens when switching light switches off and when operating furnace motors or motor-driven vacuum cleaners. An AFCI breaker will recognize these different types of arcing and only take action when necessary.
Differentiating Arcs
It can differentiate between the two main types of arcs:
- Series Arcs: this type of arcing happens on a single wire, for example when a conductor breaks but keeps making intermittent contact through the gap’
- Parallel Arcs: mostly happens due to damaged insulation, and affects two adjacent wires, such as a hot wire and a neutral wire.
Protecting the Circuit
As soon as it detects a potentially hazardous arc, the device immediately interrupts the circuit using an internal relay to disconnect power. By stopping the flow of electricity, it thus prevents the arc from igniting a fire or causing any damage.
Just like a conventional circuit breaker, an AFCI breaker can be reset manually after tripping.
Difference Between AFCI and GFCI
Now that we understand how an AFCI breaker works, it is important to note that it cannot replace the GFCI in any circuit. The two play complementary roles to provide comprehensive protection.
While an arc fault breaker interrupts power supply when it detects arcing in a circuit, a GFCI protects people from the risk of electrocution of electric shock in the event of a ground fault. GFCIs work by monitoring the balance of current in a circuit. When they detect imbalances, such as more current flowing through the live wire than the neutral wire (proof of an electric leak to the ground), they shut the power off.
Compliance Requirements: The National Electric Code and Arc Fault Breakers
As the benchmark for electrical safety, the National Electric Code (NEC) has regulations covering every aspect of electrical wiring and equipment, including AFCIs. The code, which is revised every three years, first introduced a requirement for arc fault breakers in 1999. At the onset, it was only mandatory for bedroom circuits in new residential constructions.
In 2002, it expanded the regulations to include every outlet in the bedroom, including smoke alarms and lighting fixtures. After expanding to include living rooms and dining rooms in 2008, it later extended to nearly all living areas including kitchens and laundry areas for new constructions in 2014.
While these regulations do not impact existing installations, any extension or upgrade of a circuit during a remodeling must get AFCI protection. Any time an electrician replaces a circuit breaker on your panel, they are mandated to use an AFCI breaker as long as you live in a jurisdiction that adheres to the NEC.
Essential Electric Supply: Your Go-To Supplier for Arc Fault Breakers and More
Protect your home and the ones you love with top-notch arc fault circuit breakers from Essential Electric Supply. We have carved out a niche for having an extensive inventory of electric parts and having them delivered in the shortest time possible.
We take pride in offering the best expertise, with a friendly team of highly knowledgeable staff members to handle your queries and concerns. Our competitive prices and industry-leading, gold standard, two-year warranty for all parts ensure that you get great value for money in every purchase.
