Controlling the Effects of an Internal Arc Fault and Benefits of Active Arc Protection in Low-Voltage Switchgear Assemblies

Internal arcs in low-voltage switchgear assemblies are rare; however, when they appear, they produce high temperatures and pressures, and emit light, noise, and toxic gases. Different methods can be implemented to control the effects of an internal arc fault and to protect personnel and assemblies from the consequences of such faults. This paper describes methods that either contain the effects of an internal arc by the design of an assembly (passive arc protection) or limit the effects of an internal arc using specialized devices (active arc protection). Additionally, the results of the internal arc fault tests conducted in an ABB laboratory demonstrate the practical application of the methods described in this paper for two test cases. Moreover, this paper shows how the verification of low-voltage switchgear assemblies under conditions of internal arc fault evolved in the standardization documents IEC TR 61641 and IEC TS 63107. Finally, it focuses on the benefits of using active arc protection systems, which offer not only enhanced protection of personnel and assemblies but also ensure reduction of downtime after a fault and positive impact from sustainability and circularity point of view.