Exploding the misconceptions and myths about arc flash issues

摘要

As a member of the NFPA 70E Committee and an instructor, I hear it all. There seems to be some common misconceptions among people that are like urban legends; they just don't go away. One of my favorites is that "You don'trnhave to worry about arc flash below 240 volts." While it may be true that an arc is more difficult to sustain at lower voltages, there have beenrnsome well-documented incidents at 208 V that have resulted in large, sustained arc flashes. This usually requires a very large short circuit available current to sustain the arc.