Determination of the Cause of Arcing Faults in Low-Voltage Switchboards

It is widely recognized that arcing faults in switchboards contain large amounts of power and can create significant damage, including melting switchboards, destroying substations, disabling ships, and causing human fatalities. While arcing faults occur with a fairly high frequency, electricity is so ubiquitous in our lives that most engineers will not personally be associated with a major arcing fault. The Navy has invested 25 years investigating the causes, behavior, and prevention of arcing failures in low- and medium-voltage switchboards. Laboratory testing used to help understand the behavior of arcs in switchboards is presented. Those data are then used to analyze actual switchboard arcing events and, thus, to determine the root causes of the events. Additional testing used to confirm the cause of each event is discussed.