We have a problem with lot lighting on this system and would appreciate any help. This is a 480 volt grounde B phase system and we don't see it a lot around here. There are a total of 36 1000watt lamps on poles and they are fed from a panel through two pole circiut breakers. Our service electrician went out after a sign company had a tech replacing lamps and ballasts. The tech claimed he was getting shocked even though the breakers were all "off". We could find no voltage present with the breakers off. With them off, we find voltage at the panel main lugs of 480 between both A and C phases to ground. Zero voltage to ground on the B phase. Then as we sequentially turn on each circuit the voltages at the panel lugs begin to drop and vary relative to the number of circuits turned on. The voltages at vairous poles also varies widely and is as low as 410 volts. The lamps do light but want to "cycle". I believe we have an improper or inadvertent connection between an ungrounded phase and the grounded phase somewhere in the system or possibly an "open" in the grounded phase somewhere. Could either condition cause the variations in voltages? :?