poorboy,

Remember that you only get voltage drop with current flow [Linked Image]

If you have a multiwire circuit with no current flow on the neutral, then there is no voltage drop in the neutral.

If there is some way that you could re-arrange your lighting circuits so that you have _three_ balanced circuits, then you could eliminate voltage drop in your neutral, and probably get to an acceptable over-all voltage drop.

You will need to consider sequencing; will there ever be some circuits on and others off? Because you will have current flow in the neutral whenever some of the circuits are off.

You might also consider using 480V line to line loads, which will eliminate the neutral entirely and again reduce the apparent voltage drop.

-Jon