Adding on to existing circuit. Worried about voltage drop.

[Str]

Doing an addition to a church and they want to add more pole lights to a run. The run is already around 3.2% voltage drop and they want to extend it another 3-500 feet. The circuit currently is using 8.5 A. They want to add 2 more poles along a private drive. It's single phase 480. Would a transformer even fix the issue of voltage drop here? The existing conduit is at capacity as the circuit has #8s to it.

Thanks.

Edit: distance of existing circuit is roughly 1056 feet

 

[retirede]

We need to know the current rating of the poles to be added. It would also help to know the type of lights - some will tolerate low voltage better than others.
But my back-of-the-napkin calculations say you’re probably going to be OK.