This fixture is wired for 240 volts, you can see the 3 wires coming out of the arm.

Almost all the MVs in National Grid territory are 240V (the only ones that aren't would be pre-1965 lights and any late-80s onward MVs such as AE 113s, 125s, or GE M-250R2s, M-400R2s).

I know with the wye power at my building you can't get 240 only 208 our only Delta service is 550 in one section . My friends have 240 Delta and L1 to L2 gets 240. L3 to earth gets the 208. Alalacis has 2kva into his building and a massive transformer room, 208 550 and 240 he has it all

Yeah I've heard of delta where one leg gives you a higher voltage! Haven't learned about it in class but I've heard about it here before. Really cool how many voltages you can get without an additional transformer to step-up or step-down the voltage. You just need the transformer on the pole!

Yes, L3 the hot leg. I will post some diagrams. In the case of 240 delta you need 3 unless it is open delta