Understanding Arc Faults and AFCI Protection
What is an Arc Fault?
An arc fault occurs when loose or damaged electrical wiring or devices create a spark or arc between metal contact points. This arcing can generate intense heat, which can ignite nearby materials like wood framing or insulation, potentially causing an electrical fire.
How to Detect an Arc Fault
Arc fault circuit interrupters (AFCIs) are designed to detect arcing and break the circuit to prevent an electrical fire. AFCIs analyze the characteristics of electrical current and can distinguish between normal and dangerous arcing conditions.
Arc Fault vs. Short Circuit vs. Ground Fault
- Arc fault: Sparking or arcing caused by loose or damaged electrical connections, which can create heat and the potential for electrical fires.
- Short circuit: Energized current strays outside the established wiring system and makes contact with the neutral or grounding pathway, causing a sudden increase in current flow and tripping the circuit breaker.
- Ground fault: Energized current makes accidental contact with a ground, causing a loss of resistance and an unimpeded flow of current that can trip the circuit breaker or, if the circuit breaker doesn’t operate fast enough, cause shock. GFCIs (ground-fault circuit interrupters) are designed to protect against ground faults and shock.
Code History of Arc Fault Protection
The National Electrical Code (NEC) has gradually increased its requirements for arc-fault protection. Since 2014, nearly all circuits supplying general outlets in living spaces are required to have AFCI protection in new construction or remodeling projects.
Why You Need Arc Fault Circuit Interrupters (AFCIs)
AFCIs are essential for fire safety and can help reduce the risk of electrical fires in homes. They detect even low-level hazardous arcing currents and shut down the circuit before an electrical fire can spark.
How Does an AFCI Work?
AFCIs use advanced electronic technology to distinguish between normal and dangerous arcing conditions. They monitor electrical currents and de-energize the circuit if they detect unwanted arcing patterns.
GFCI vs. AFCI
GFCIs protect against shock by sensing short circuits to ground, while AFCIs protect against fire by detecting arcing. Both types of protection are important, and in new or remodeled wiring, many locations may require both GFCI and AFCI protection. This can be achieved using AFCI circuit breakers combined with GFCI receptacles, or by using combination AFCI/GFCI circuit breakers.
FAQ
What is the difference between GFCI and AFCI?
GFCIs protect against shock, while AFCIs protect against electrical fires.
How do you fix an arc fault?
Try unplugging everything in the circuit and plugging devices back in one by one to identify the culprit. Check for broken cords or damaged wires, and consider calling a licensed electrician if you can’t isolate the problem.
What causes an arc fault to the ground?
An arc fault to ground occurs when energized current makes accidental contact with a ground path.
What would cause an arc fault breaker to trip?
Poor connections, overloaded circuits, dampness, and incompatible appliances or devices can all cause arc fault breakers to trip.
