You are correct! Annex D of NFPA 70E has the wrong units for En

- it IS cal/cm^2. I am surprised this is still carried over into the 2009 edition. IEEE is required to use all metric so En in IEEE 1584 actually does not identify the units since it is not completely metric. It just uses the label "normalized incident energy". The units of Joules/cm^2 occurs AFTER you multiply by the conversion 4.184