I am trying to install a 30amp sub-panel out to my barn from the house. The wire run is approximately 200 feet including the internal wire distance in both buildings. What wire size do I need to use? Will 8/3 with ground be sufficient?

#4 copper will be needed to deliver 30 amps 120 volts 200 feet.

My oversight... sorry. 30 amps 240V at 200 feet. What is the required wire size?

#6