lighting circuits run a long distance are acting in peculiar way-a different set of lights come on every time we energize, making me suspect that not enough voltage is present to fire all ballasts at once---and then the other lights come on gradually. I'm wondering if this is due to voltage drop although we upped wire size to compensate. I wonder if and how sharing a neutral on these long runs affects the voltage drop situation. The lights are run through a contactor controlled by a photocell but I don't think that makes a difference. Any clues---help?