Why Care About Arcing Faults?

Arcing faults are a real hazard in electrical systems…including the home. Avoid fires by understanding their causes.

UL® defines an arcing fault as an unintentional arcing condition in a circuit. Arcing creates high intensity heating at the point of the arc resulting in burning particles that may over time ignite surrounding material, such as wood framing or insulation.

The temperatures of these arcs can exceed 10,000 degrees Fahrenheit. Repeated arcing can create carbon paths that are the foundation for continued higher current arcing generating even higher temperatures.

Know their causes

Example conditions where arc faults may start include:

  • Damaged Wires
  • Worn electrical insulation
  • Wires or cords in contact with vibrating metal
  • Overheated or stressed electrical cords and wires
  • Misapplied or damaged electrical appliances

Wires located behind walls can be accidentally punctured by a screw or drill bit damaging the insulation of the wiring.

Extension or appliance cords that are damaged or have worn or cracked insulation can contribute to electrical arcing.

Cables that are improperly nailed or stapled too tightly against a wall stud can sever insulation and cause arcing.

Furniture pushed against or resting on electrical cords can damage the wire insulation. Damaged cords can become a potential condition for arcing.

Nails carelessly driven into walls can break wire insulation and cause arcing

Cord insulation can be deteriorated by heat generated by hot air ducts or sunlight.

Cords caught in door jams can deteriorate the cable insulation through the action of opening and closing, allowing arcing to occur