Conduit is always better because stuff happens. 18" depth.
800 feet is a long ass trench :yes:
Here is a voltage drop calculator. Find out the amperage on your pump and plug it in. It looks like #4's will carry a 10 amp load 800 feet with a voltage drop of only 2%
#6's will lose over 3% and that is a touch too much IMO.
http://www.electrician2.com/calculators/vd_calculator_initial.html
800 feet is a long ass trench :yes:
Here is a voltage drop calculator. Find out the amperage on your pump and plug it in. It looks like #4's will carry a 10 amp load 800 feet with a voltage drop of only 2%
#6's will lose over 3% and that is a touch too much IMO.
http://www.electrician2.com/calculators/vd_calculator_initial.html