Design aspects of industrial distribution systems to limit ARC flash hazard

The industrial distribution systems have been designed in USA, considering prevalent standards, i.e., ANSI, IEEE, NEC, OSHA etc. and the arc flash were not a consideration for designing electrical power systems in the industry. Functionality and economics were the important factors, and will always be so. However, the arc flash analysis and limiting the incident energy will usher a new parameter in the system design. It can be demonstrated that in many current installations and new installations designed without considerations of limiting the arc flash energy, the hazard risk category exceeds the highest Class 4 of PPE, i.e., ATPV (callcm²) of 40. This paper discusses typical industrial distribution systems at low-voltage and medium-voltage levels and demonstrates the impact of system design decisions and protection on the incident energy and arc flash hazard reduction