I did figure in the extra 25% for the lighting and the equipment I figured would be continuous. The 489 amps I got reflects that. So, at this point, am I done, or do I need to add 20% of this load to get the breaker size? Forgive me if I didn't see the answer in these posts, but this has been driving me batty. Thanks again for not only the help, but for being so to the point and making it understandable
With all due respect, I believe you may be thinking about this a little backwards as you are using the load to size the breaker with no mention of using the load to size the feeders. When sizing circuits, it is important to remember that you calculate the loads to size the conductors, not the OCPD. You then size the OCPD as required to protect the conductors.
In this specific case, if the 489 amps is the calculated load (based on Article 220 requirements for continuous loads, permitted demand factors, etc.), you would then select two sets of #250 kcmil conductors (assuming terminals are rated at 75 degrees C, copper conductors are being used, and derating is not an issue). The parallel sets of #250 kcmil conductors are rated at a total ampacity of 510 amps. You would then select the OCPD based on this ampacity. I, personally, would go with the 500 amp breaker, but 240.4(B) may technically let those conductors be protected by a 600 amp OCPD if the conditions within that section are met.