More than 30 percent of all building fires—approximately 2,000 fires per day just in Europe alone—are caused by faults in the electrical installation. Damaged cable insulation, which can easily happen with age, improper use or installation, or even bites from rodents, can result in arc faults – the discharge of electricity between two or more wires. If the power is not immediately interrupted this discharge generates heat, which can start a fire. Wooden structures and buildings with combustible material are particularly vulnerable, as a single spark has the potential to ignite a fire destroying the entire building. Sleeping accommodations and locations that contain irreplaceable goods are also vulnerable. To reduce the risk of fire due to arc faults and protect buildings ABB developed Arc Fault Detection Devices (AFDDs).
Most arc faults are not detected by conventional circuit protective devices, such as miniature circuit breakers and residual current devices, which are designed to primarily detect earth leakage currents and over currents. AFDDs are extremely sensitive and designed to sense and respond only to potentially dangerous arcs. They use a special algorithm to detect dangerous arcs. An AFDD has a digital microcontroller and other electronic devices built in to constantly monitor the wave form of the power in the observed circuit and compares it with wave forms considered safe. As soon as a wave form typical for an arc fault is detected, the AFDD interrupts the flow of power.
ABB offers several versions of AFDDs, integrated with miniature circuit breakers (protection against arc faults and over currents) or even integrated in residual current circuit breaker with over current protection with additional earth fault current detection. The first product of this kind, the S-ARC1 was introduced in 2017. Today AFDDs from ABB are available in more than 30 countries, with demand increasing significantly. Historic Dutch windmills or the townhall in Dordrecht, the Netherlands are now protected from fires caused by arc faults with AFDDs from ABB.