Arc-Flash Energy Reduction Techniques: Zone-Selective Interlocking and Energy-Reducing Maintenance Switching

The safety of personnel that work on electrical power distribution systems has received increasing attention from a number of standards and regulatory organizations in recent years. Organizations such as the IEEE, the Occupational Safety and Health Administration, the National Fire Protection Association, and several other groups are actively engaged in ongoing discussions on improving electrical worker safety, specifically in the area of protection from arc-flash hazards. While standards developed by these organizations discuss improvement opportunities, there are a number of techniques and technologies that are currently available for mitigating arc-flash exposure. This paper will provide a general overview of the key arc-flash reduction techniques and will specifically focus on two of these technologies-zone-selective interlocking and arc energy reduction maintenance switch systems. The benefits, expected performance, and the appropriate application of each of these arc-flash reduction solutions will be presented.