2000' is pushing it with 18awg multistrand. Not sure about the other gauges.
Voltage Loss= (10.4 x Length x Amps) / Circular Mills of Wire (1680 for 18awg)
I don't use any voltage loss greater than 4.5V
This post has been edited 1 times, last edit by "Central Irrigation" (Mar 8th 2011, 6:46pm)