The term “arc fault” refers to a situation that loose or corroded wiring connections create an intermittent contact to cause an electrical current to spark or arc between metal contact points. You are hearing arcing when you hear a light switch or outlet buzzing or hissing. This arcing translates to heat and then provides the trigger for electrical fires, this actually break down the insulation surrounding individual conducting wires. Hearing a switch buzz does not mean the fire is necessarily imminent, but it does mean there is a potential danger that should be addressed.
Arc Fault vs. Ground Fault vs. Short Circuit
The terms arc fault, ground fault, and short-circuit sometimes caused confusions, but they actually have different meanings, and each requires a different strategy for prevention.
- An arc fault, as mentioned above, occurs when loose wire connections or corroded wires cause sparking or arcing, it might create heat and the potential for electrical fires. It might be a precursor to a short circuit or ground fault, but in and of itself, an arc fault may not shut down either a GFCI or a circuit breaker. The normal means of guarding against arc faults is an AFCI (arc-fault circuit interrupter)—either an AFCI outlet or an AFCI circuit breaker. AFCIs are intended to prevent (guard against) the danger of fire.
- A ground fault means a specific type of short circuit in which energized “hot” current makes accidental contact with a ground. Sometimes, a ground fault is actually known as a “short-to-ground.” Like other types of short circuits, circuit wires lose resistance during a ground fault, and this causes an unimpeded flow of current that should cause the circuit breaker to trip. However, the circuit breaker may not operate fast enough to prevent shock, the electrical Code requires special protective devices for this reason, that’s why GFCIs (ground-fault circuit interrupters) need to be installed in locations where ground faults are most likely to occur, such as outlets near plumbing pipes or in outdoor locations. They can shut down a circuit even before a shock is felt because these devices sense power changes very fast. GFCIs, therefore, are a safety device intended mostly to guard against shock.
- A short circuit refers to any situation in which energized “hot” current strays outside the established wiring system and makes contact with either the neutral wiring pathway or the grounding pathway. The flow of current loses its resistance and suddenly increases in volume when this happens. This quickly causes the flow to exceed the amperage capacity of the circuit breaker controlling the circuit, which normally trips to stop the flow of current.
Code History of Arc Fault Protection
The NEC (National Electrical Code) revise one time every three years, it has gradually increased its requirements for arc-fault protection on circuits.
What Is Arc-Fault Protection?
The word “arc-fault protection” refers to any device that is designed to guard against faulty connections causing arcing, or sparking. A detection device senses the electrical arc and breaks the circuit to prevent an electrical fire. Arc-fault protection devices protect people from danger and are essential for fire safety.
In 1999, the Code began requiring AFCI protection in all circuits feeding bedroom outlets, and from the year 2014 on, nearly all circuits supplying general outlets in living spaces are required to have AFCI protection in new construction or in remodeling projects.
As of the 2017 edition of the NEC, the wording of Section 210.12 states:
All 120-volt, single-phase, 15- and 20-ampere branch circuits supplying outlets or devices installed in dwelling unit kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, laundry areas, or similar rooms or areas shall be protected by AFCIs.
Normally, circuits receive AFCI protection by means of special AFCI circuit breakers that protect all outlets and devices along the circuit, but where this is not practical, you can use AFCI outlets as backup solutions.
AFCI protection is not necessary for existing installations, but where a circuit is extended or updated during remodeling, it must then receive AFCI protection. Thus, an electrician who works on your system is obligated to update the circuit with AFCI protection as part of any work he does on it. In practical terms, it means that virtually all circuit breaker replacements will now be made with AFCI breakers in any jurisdiction to follow the NEC (National Electrical Code).
Not all communities comply with the NEC, however, please check with local authorities for requirements regarding AFCI protection.
Post time: Mar-01-2023