Total Building Load in KVA

Hi All,


I have been asked to provide the total electrical load of a building.  The max load per phase is 426.3A, on a 3-phase supply.  The majority of this is made up of 1-phase (230V) loads, with a few 3-phase loads mixed in there.  I have designed the electrical distribution such that the loads are split as equally as possible, but I have a question on how to calculate the total KVA value for this supply.  I'm getting a little confused with the information provided online and thought I would check this with a reliable source (you guys!).  Can someone confirm which of the following is the correct calculation, please?


1) I = 426.3A (per phase).  V = 400V (per phase).  Therefore: (426.3 * 400 * 1.732) / 1000 = (426.3 * 692.8) / 1000 = 295.34KVA


2) I = 426.3A (per phase).  V = 230V (per phase).  Therefore: (426.3 * 230 * 1.732) / 1000 = (426.3 * 398.36) / 1000 = 169.82KVA


Many thanks in advance,


MJB