Current limiting arc flash quenching system for improved incident energy reduction

In response to a growing concern to mitigate arc flash incident energy hazards, the latest edition of the National Electric Code NFPA70-2017 includes requirements for reducing clearing time of overcurrent protective devices with a continuous current rating of 1200A or higher. Section 240.87 lists seven options for reducing arc fault energy. This paper will briefly review the defined methods of reducing incident energy as outlined in the Standard, with focus on option 4: energy-reducing arc flash mitigation systems.