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Hello,
I am experiencing what I imagine to be a very basic wiring problem but which is causing me some considerable frustration...
I have a system comprised of 26 panels (325, 340 & 370w) split into 3 separate strings (for each type of panel exclusively), each with their own combiner box and charge controller. But I have been unable to utilize more than 2 panels on any given string, as I have simply not been able to complete a "successful" parallel connection…
My design configuration is to have 2 panels wired in series, and then each series-pair combined in parallel to supply the controller.
My series connections I make by wiring the + of one panel with the - of the second panel. Using my multimeter I see a doubling of voltage, as expected.
I then try to make a parallel connection by wiring the + of one series-pair (as above) to the + of the second series-pair, and the - of the first to the - of the second. My understanding is that I should see a summing of the amperages of the two series-pairs. But I do not. Instead my multimeter reads not only the same voltage (as expected) but also the same amperage of only one of the series-pairs.
For example, with 2 40v panels, I have one series pair reading 80V and 10.4A, and another series-pair reading 80V and 10.2A. I wire the + to + and the - to - from one pair to the other, and I still read 80V and 10.4A.
Should I not be getting 80V and 20.6A?
I have tried making this parallel connection directly between pairs using 2AWG wire (which I since learned is a bad idea!), and using a combiner box with independent relays and switches, but the result is the same in either case. And with any of the 3 types of panels. Even with a full 6-string combiner box where I read 6 inputs all at say 80V and 10-10.5A each, I can never get an output of more than 80V and 10.5A.
I just can not figure out what is going on, what I have missed or done wrong, and am desperately in need of help.
It does not matter if there is no load or the batteries are pretty full on charge does it? Should I not be able to read all the charge being generated from my panels regardless, if I am measuring the current before (panel-side of) the charge controller?
Any help or direction would be so incredibly appreciated.
Feeling lost in the jungle with solar panels,
Ahki
I am experiencing what I imagine to be a very basic wiring problem but which is causing me some considerable frustration...
I have a system comprised of 26 panels (325, 340 & 370w) split into 3 separate strings (for each type of panel exclusively), each with their own combiner box and charge controller. But I have been unable to utilize more than 2 panels on any given string, as I have simply not been able to complete a "successful" parallel connection…
My design configuration is to have 2 panels wired in series, and then each series-pair combined in parallel to supply the controller.
My series connections I make by wiring the + of one panel with the - of the second panel. Using my multimeter I see a doubling of voltage, as expected.
I then try to make a parallel connection by wiring the + of one series-pair (as above) to the + of the second series-pair, and the - of the first to the - of the second. My understanding is that I should see a summing of the amperages of the two series-pairs. But I do not. Instead my multimeter reads not only the same voltage (as expected) but also the same amperage of only one of the series-pairs.
For example, with 2 40v panels, I have one series pair reading 80V and 10.4A, and another series-pair reading 80V and 10.2A. I wire the + to + and the - to - from one pair to the other, and I still read 80V and 10.4A.
Should I not be getting 80V and 20.6A?
I have tried making this parallel connection directly between pairs using 2AWG wire (which I since learned is a bad idea!), and using a combiner box with independent relays and switches, but the result is the same in either case. And with any of the 3 types of panels. Even with a full 6-string combiner box where I read 6 inputs all at say 80V and 10-10.5A each, I can never get an output of more than 80V and 10.5A.
I just can not figure out what is going on, what I have missed or done wrong, and am desperately in need of help.
It does not matter if there is no load or the batteries are pretty full on charge does it? Should I not be able to read all the charge being generated from my panels regardless, if I am measuring the current before (panel-side of) the charge controller?
Any help or direction would be so incredibly appreciated.
Feeling lost in the jungle with solar panels,
Ahki
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