Jerry, A long distance wire run is practical now days using a high voltage controller. Have a look at Schneider and Morningstar 600Vdc controllers. Not sure what you mean "by nothing can be changed but wire size” but you will have to rewire the strings into series and protect the wire run.
Larry Crutcher Starlight Solar Power Systems On Jul 22, 2015, at 10:37 AM, Jerry Shafer <jerrysgarag...@gmail.com> wrote: Wrenches Some time back there was discussion on the conductor size and efficiency rating requirement for long DC runs. What I am looking at is this, 400 feet of MCM 400 to keep the line loss at or below 1% per NEC code for an off grid application, cost vs return is not acceptable. 2/0 is less than 2.5% and the cost is far less. Specs are 4 strings of 3, 250 watt modules feeding one Outback FM 80 charge controller. There are lots of things I can do like SMA instread, or 200 VDC charge controller but nothing can be changed except the wire gauge. Does anyone recall a thread with this topic. thoughts ?? Jerry ________________________
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