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NEC recommends maximum allowable voltage drops not to exceed 3% on a branch circuit. For feeder/ branch combos the NEC recommends that the voltage shall not drop by more than 5% to the furthest outlet.
The main consideration that is enforced is NEC 250-122. You must compensate your grounding conductor when you increase in conductor size to compensate for voltage drops.
Direct bury or conduit:
#4/0 copper provides for 2.95%
#2/0 copper provides for 4.35%
#1/0 copper provides for 5.19%
Interestingly enough, using a separate calculator 3/0 copper with 3% voltage drop can be 780.5 feet long.
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What size aluminum wire needed for 30 amp at 240 volt for 500 feet underground?
A 1/0 aluminum conductor will limit the voltage drop to 3% or less when supplying 30 amps for 500 feet on a 240 volt system.
What gauge underground wire for 110 volt 15 amp 700 ft for a pond pump?
A #1 copper conductor will limit the voltage drop to 3% when supplying 15 amps for 700 feet on a 120 volt system.
What is the wire size for 208 volt?
As with any electrical installation, the wire size used depends on the expected maximum current the wire will carry. That cannot be determined by voltage alone.
What size conductor is needed to carry 25 amps 120 volt AC over 400 feet?
A #4 copper conductor will limit the voltage drop to 3% or less when supplying 25 amps for 400 feet on a 120 volt system.
What is the correct wire size to install with a distance of 200 feet for a 100 amp single phase underground service?
This is a voltage drop question. A #1 copper conductor will limit the voltage drop to 3% or less when supplying 100 amps for 200 feet on a 240 volt system. Or a 3/0 copper conductor will limit the voltage drop to 3% or less when supplying 100 amps for 200 feet on a 120 volt system. In your question you sis not stipulate what the working voltage is.
