Series arc faults in low-voltage AC electrical installations

This thesis provides a complete analysis of all the topics related to series arc faults in low-voltage electrical installations. The part played by series arc faults in the outbreak of hazardous electrical fires is explained by using fire statistics, performing an electrical and thermal characterization of the phenomenon, and comparing with other electrical faults their ability to ignite an insulation material. The analysis demonstrates that the series arc fault generates a heat stress that largely exceeds the ignition threshold of insulation polymers. Other electrical faults such as bolted short-circuit, overload, earth leakage, and glowing fault result in much lower risks of fire ignition. The principles of arc fault detection are explained and the contribution of the active protection AFDD (arc fault detection device) is taken into account in this analysis. The option of achieving a passive protection using appropriate insulation materials is also explored. The performance requirements described in the product standard of AFDD are reviewed and recommendations for improving the standards are proposed.