I was directing my posting to you hh. I'm a licesned electrician too, with 2 years of EE. Now I'm trying my hand at an hvac apprenticeship. If that padmount transformer is only allocated for your building, that is a big plus. If I was you Anferneybra, I wouldn't be advertising such a large undertaking on forums like this. Find a few electrical contractors experienced with high voltages and get their advice. They would love to make the money.
Three 500A 3 pole disconnects and 3 x 100KVA transformers, was an issue with having the cans indoor in a wooden structure, had to move them to a pole, even with a fuselink disconnect attached to a small winch, which would turn on for 2 seconds and pull the fuselink off, had to be manually put back, was set up to trip all the power in a major emergency.
Success on your endeavor, wish I was your contractor for all your needs....
Grow Big...Pay Big.. That is for sure brother. Sounds like you are giving him a bro deal. 120 lamps in each room, correct? You know its comedic how puckered someone's a**hole can get when you hand them a bid with that many zero's on it. Or how their eyes will glaze over as they stand there with a vacant deer in the headlights expression for a few seconds.
Employing a step down transformer fed from the main service panel works well to feed HID lighting and any miscellaneous general use. I do however prefer employing 480v, when available, to the lighting and all motor loads. On previous jobs we have installed the 480v/1⦰ powerhouse ballasts and they performed admirably. In cases where we have renovated an existing operation we noticed a somewhat significant savings on our utility bill. What is your opinion on the 480v ballast hvac guy?
Haven't installed that ballast. Never seen anyone using them.