Registered: 1448788994 Posts: 10
Reply with quote #1
Hello, I am setting up an off grid solar system that I need some done it themselvers approval.
If I start by getting this Charge controller: http://www.amazon.com/Tracer-Tracer2210RN-Charge-Controller-Regulator/dp/B008KWPH12/ref=sr_1_1?s=automotive&ie=UTF8&qid=1454661424&sr=1-1&keywords=tracer+20amp 20amps, with four regony 12volt 5.6amp panels paired to 24 volt running on a 10 awg 100' cable. In a calculator I found that you loose 2.7amps (I am not sure if that is one way, or 2.7 for both ways if so I would drop the cable length to 50'). That would drop the 22.4amp down to 19.7 max.
Would this system fly? I prefer to not spend a lot of money right now and just get two regony panels with a MPPT controller that can accommodate more as I need.
Also does anyone know of a good place to buy panels near seattle? everywhere I have looked has shipping costs almost as much as the panels themselves.
Registered: 1424977490 Posts: 470
Registered: 1388591029 Posts: 2,539
Reply with quote #3
The specs on the controller say max BATTERY current is 20 amps. If you use a 24v battery system it would work, if a 12v system, probably not.
The specs also say max PV input power is 260w for a 12v system, or 520w for a 24v system. You could wire all 4 panels in series for efficiency. __________________ Willie, Tampa Bay
Registered: 1413680577 Posts: 9
Reply with quote #4
What you have to remember is that the power loss in a cable is equal to the resistance of the cable times the current squared. What that means is that if you have 10 amps traveling in a wire that has a resistance of 1 ohm then the loss is equal to 1 times 10 squared equals 100 watts. The voltage drop is equal to the current times the resistance. That would be 1 times 10 equals a 10 volt loss. There is a project that I am working on that requires 25 volts at 4 amps about 300 feet away. I have to put another solar panel in series so that I get 25 volts to the dc motor on the other end of the line running the swamp cooler. Al
Registered: 1437076587 Posts: 13
Reply with quote #5
a nominal 20 amp array can put out substantially more than 20amps on a cold semi cloudy day due to reflection.