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Arc fault

Definition

An unintended electrical discharge across a gap or through degraded insulation that releases energy as heat and light. Arc faults are classified as series (along a conductor) or parallel (between conductors at different potentials).

Related terms

AFCI
Arc-fault circuit interrupter. A device that detects the high-frequency signature of arcing current and opens the circuit. Required by the National Electrical...
Alloying
Incorporation of a foreign metal (steel, zinc, aluminium) into a copper arc bead. The arc's intense temperature fuses adjacent metals together. The...
Notching
A V-shaped or crescent-shaped indentation in copper at an arc site, caused by localised material ejection during the arc event. Notching on...
Primary arc
An arc that preceded and caused the fire. Its markers on copper conductors appear before any fire damage has reached that location.
Secondary arc
Arc damage created after a fire was already burning, caused by the fire melting insulation and shorting conductors. These markers are consequences...

Explained in

  • Electrical Fire Failure AnalysisAn unintended electrical discharge across a gap or through degraded insulation that releases energy as heat and light. Arc faults are classified as series (alo...

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