Understanding Electrical Arcs. International Association of Arson Investigators
Abstract: This article discusses electrical arcs and why they
occur. The IAAI's statistics show that less than 30% of electrical arcing
instances result in fires. Electrical arcs are caused by mechanical failure,
water penetration, and overloading current. Charts are provided to illustrate
the different situations in which an arc will occur. The factors that affect
arc resistance include: the medium in which the arc occurs, the sparkover
voltage, intermittent or erratic contact, and the ionization of the air.
If these factors are combined, the protection devices may fail. Although
many arcs are self-clearing, a sustained arc can failure somewhere else
in the circuit.
For more information, contact:
International Association of Arson Investigators (IAAI)
300 Broadway Suite 100
St. Louis, MO 63102-2808