As per NFPA 70E, we have 3 boundaries to mark(AFB, limited and restricted). It is easy to mark and follow only one boundary which is greater than two. Sometimes AFB is more than limited approach boundary, so we marked the AFB and follow that.

But sometimes AFB is very less for lighting boards and power distribution boards. Also it is not feasible to mark limited boundary as it is very big for small board placed in normal working area and not even AFB because it is too small to mark.

I need some suggestions on it, that whether to mark boundary to LDB & PDB’s. If yes, which boundary need to mark? READ MORE.