Arcing faults in low and medium voltage electrical systems - Why do they persist?

Abstract

Arcing faults can occur in low and medium voltage systems, causing high temperatures of the order of tens of thousands of degrees, resulting in severe damage to equipment and arc flash hazards with severe burns and possibly death. The electrical industry has adopted various codes and standards in an attempt to improve and enhance equipment safety, and decrease the possibility of the occurrence of arcing faults and thus mitigate the dangerous effects of arcing faults to humans. However, the NEC and other standards do not address the hazards associated when the equipment doors are open and a maintenance worker accidentally creates an arcing fault. Incidents of arcing faults that we have worked on were reviewed to determine the computed damaging effects of that fault, the degree of destruction, and specifically identify the root cause of that particular arcing fault. The objective of this paper is to review and investigate the reason for the large number of arcing faults in low and medium voltage electrical systems and further to determine why, there are so many arcing fault incidents in spite of increased levels of protection and installation of fail-safe mechanisms and procedures.