While minimum approach distances are unrelated to arc flash boundaries, they come into play for utility distribution voltages: If the arc flash boundary is less than the MAD, then it becomes a moot topic because the line worker will be futher away than the boundary. My question is this: Which MAD should utilities use?
The numbers listed in OSHA 1910.269(I)(10), Table R-6 are different from those listed in the NESC, Tables 441-1 and 441-2, especially in the 15kV to 25kV range. Also, the separation of single phase and three phase distances in Tables 441-1 and 441-2 seems non-sensical.