Dave-Sparky wrote:

I also generally agree with what Cedarhill wrote with one exception and several assumptions.

You will have to get the power out and back, so the total wire length is actually 130 feet, not 65.

The assumptions are that the wire is copper, not aluminum and solid not stranded. If these are not correct they the voltage drop will be slightly higher, but still safe.

Thus, the actual voltage drop will be approximately 4 volts at full load.

Good engineering practice is to design for a worst case of 5% or with a 120 volt source 6 volts.

Dave

Bit Bucket wrote:



...only 65' would be computed in this case, out and back is not how it is done.

This is a myth perpetuated on many forums.

Formula #1 (no out and back)

Formula #2 (no out and back)

Formula #3 (no out and back)

All of these sources refer to "one way distance" or "distance from power supply to load", etc.

Those of us in the electrical field that size feeder and branch circuit conductors, etc. for engineering approval, know to use the "one way distance".