I am adding a 100 Amp Distribution Panel to my Pole Barn that is located about 350 Ft awayI will be burying the cableI would prefer Aluminum as it is cheaperI am told I need to run 4 conductor from my main panel out there and then also have a ground at the pole barnMy question is what size cable should I purchase for direct burial that will leave me at lease 90 amps useable at the distribution panel 350' away and be compliant with current NEC standards.
Take your plans to the electrical permit department of your local building inspectorsWhen you get the plans approved, ask the inspector for the cable size requirements for that runIf they are too busy to supply the answer, then call a qualified professional electrician to do the workThey can calculate the IR drop for that length of run and what size wire you need to do the workYour ditch needs to be at least 3 feet down and certain cover requirements including warning tape are needed Type UF 1/0 aluminum wire is rated for 100 amps and has a resistance of .20 ohms per thousand feetthe data is from the 1993 code book but the physical properties haven't changed that much for aluminum or copper over the centuriesI'll let you do the calculations yourselfYour computer should have a calculator function built in.
