Function and use of arc fault protection systems in low-voltage switchgear installations

The thermal risk for electrotechnical switchgear installations resulting from arc faults is considered and assessed based on the "Guideline for the selection of personal protective equipment when exposed to the thermal effects of an electric fault arc" published by the ISSA (International Social Security Association ). In this context, suitable "personal protective equipment" (PPE) must be worn to protect workers from second-degree burns. However, the protective effect of this PPE is limited depending on the arc fault energy to be expected. Technical measures can also be implemented to additionally protect workers during live working. Arc fault protection systems are capable of reducing the arc energy to an acceptable level by limiting the persistence of the arc fault to some milliseconds. This paper describes the structure, mode of operation and implementation of these protection systems.