IEC 60364-4-42: LV Electrical Installation Thermal Protection — AFDD Arc Fault Detection

Most Electrical Fires Are Not Caused by Short Circuits — But by Series Arcs That Breakers Never Trip On

IEC 60364-4-42:2014 covers thermal effects protection in LV installations. 25–30% of building fires are electrical; most originate from series arcs at broken conductors with current below rated value — breakers never trip. AFDDs detect arc-characteristic high-frequency noise and current distortion.

TNLab — Breakers protect against overload and short-circuit, but only AFDDs detect the series arcs that cause fires.