Word of the Day
26 August 2026
arc fault
An undesired and uncontrolled electric arc from one conductor through the air (or other gas) to a conductor at ground potential or a different voltage phase.
Why this one
An uncontrolled arc between conductors. The reason modern breakers watch for a waveform signature and not just for current.
In use
The scorch marks on that terminal block say arc fault, not overload, so I want the whole panel opened up before we energise anything.
Written by our editors to show how the term is used, not a recorded quotation.Sources
- Definition sourceWiktionary
- Supporting sourceArc-fault circuit interruptersU.S. Consumer Product Safety Commission