Hi, I have used the Midnite string tool and have two options. Three parallel strings of two panels or six parallel strings of one panel. The main difference between the two is PV array current of 25 amps or 51 amps and MPPV of 74 volts or 37 volts. Can anyone tell me which would be best? I'm guessing the 6x1 as the current to the controller is lower so lower losses. The distance between is about 15 meters.
Thanks,
Quote from: asdex on September 14, 2014, 01:40:41 AM
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I'm guessing the 6x1 as the current to the controller is lower so lower losses.
Did you mistype that? The current is lower and voltage higher with the 3x2 configuration ::)
dgd
Hi, yes I did miss type that. The current is lower in the 2x3 array.
Thanks,
Quote from: asdex on September 14, 2014, 01:40:41 AM
Hi, I have used the Midnite string tool and have two options. Three parallel strings of two panels or six parallel strings of one panel. The main difference between the two is PV array current of 25 amps or 51 amps and MPPV of 74 volts or 37 volts. Can anyone tell me which would be best?
What would be best is to switch to a system voltage of 24 (or 48) volts. You've got 1850 watts of panel on a 12 volt system... that's more than a Classic can handle in a 12 volt system.
Also, you've got four batteries is parallel. That is poor design. You could take the same eight batteries and reconfigure them into two strings at 24 or one string at 48 volts.
Your question about which is better (3 strings or 6 strings), is a tough one. With 6 strings and a distance of 15 meters you would want #2 cable.... after the circuit breaker you would have to step it down to #4 wire to fit in the Classic.
With 3 strings, the Classic is a bit less efficient... not the best thing when you are operating at its limits of heat production.
--vtMaps
Thanks yes I was planning on a 24 volt system with new batteries and the existing ones are getting a bit old.. The panel total wattage comes out at 1920 watts. I'm also considering 48 volts but would then need a voltage reducer to run the water pump, LED lights, radio. Also a 48 volt inverter of about 2000 watts. Same with 24 volts but at least the pumps, lights, etc are easier to find.
Cheers,