The Possibilities to Reduce Arc Flash Exposure with Arc Fault Eliminators

Abstract

This paper presents a method to limit the arc energy and hence the hazard risk category value according to IEEE 1584 by using a system of two oppositely connected multi-sectional thyristor branches. A test circuit for testing the effectiveness of a thyristor arc eliminator was designed and constructed. Arc ignition inside electrical switchgear can be a source of danger for technical personnel. The arc energy calculated according to the algorithms in IEEE 1584 can be significantly reduced by using multi-sectional arc eliminator MSAE. For the actual measuring object, the calculation of the hazardous arc flash zone and the hazard category was carried out for the system not equipped with an arc eliminator, and then the same was performed in a system with an arc eliminator. In parallel, the pressure inside the closed polyvinyl chloride (PVC) electrical box enclosure was measured and then compared with the calculated pressures that could occur during an arc fault. It was found that a Multi-Sectional Arc Eliminator (MSAE) effectively protects devices supplied from low voltage networks against the effects of short circuit or arc fault, such as the sudden increase of gas pressure inside the switchboard, which may cause it to break, significantly reduce the loss of electrode material, limit the spread of hot electrode material outside the switchgear, and also significantly reduces the energy of the electric arc.