Based on real-world test data and investigation results from on-the-job safety-related incidents, we have found low-voltage arc flash energy can be underestimated. “Low voltage” in the NESC is defined as 50 volts (V) to 600V (ac). Specifically, one area of concern is 480V equipment, because 480V, three-phase related arc flash incidents can have severe consequences.

It’s important for installers and inspectors to fully grasp the scopes of the NESC and NEC, how and where each of them applies and the point of demarcation where one code yields to the other.