As I read the ROP;
110-16, new section;
Switchboards, panelboards, and motor control centers installed in other than residential occupancies shall be marked in the field to indicate energy in calories per square centimeter for a worker at 18"
see NFPA 70E-2000 for the calc.
Emb=1038.7 Db 1.4738 TA ( 0.0093F(sq) + 5.9675)
Emb= incident energy
De=Distance fron arc in inches (18")
TA= Arc duration in seconds
F= bolted fault short circuit calc.
It looks as if they are defining what could easily be items that vary greatly, for instance, is 1.4738 an average arc duration? , does F,"bolted fault short circuit calc" apply only to the bolted variety of panelboards ? Why 18", is this an arbitrary distance ,relative to what? the average sparky's arm length? Is this the only means of providing this info, the only calc?
Don, I don't mind having to do this calc.if it's required ,I'm just having a little trouble with it's variables........