Hey guys!

Lots of good information on this forum. As such, I have been a lurker for quite some time, and have been able to answer most of my own questions without the need to officially ask them. =)

Unfortunately, I have run into a small snag, and just cannot figure out the math on this one. Seems like a simple problem, so hopefully it won't been too much trouble to answer!

Basically, I have 12 solar panels installed on my RV roof, each wired 2 to a series, then 6 strings of those 2 all placed in parallel with each other. The end result looks like this:

36V.png

I chose this connection method to both a) help me avoid the negative repercussions of shade, as I often deal with when parking my RV, but b) keep my overall amperage low enough to use 8 gauge wiring to my solar controller (from the 3 way splitter onward). Indeed, I could have gone 4 to a series, but because I had started with 2 each, and grew from there at a rate of 2 panels at a time, rewiring the whole shebang would be a nightmare, and I am trying to avoid doing that if at all possible!

So here's my question: where on earth do I place fuses in this setup, if any are even necessary? The specs for each of my panels (all identical btw) are as such: Maximum Power: 100W

Maximum System Voltage: 600V DC

Optimum Operating Voltage (Vmp): 17.9V

Open-Circuit Voltage (Voc): 21.6V

Optimum Operating Current (Imp): 5.72A

Short-Circuit Current (Isc): 6.24A

Maximum Series Fuse Rating：15A

So obviously, running each pair in a series keeps me under that 15 amp fuse maximum, per pair of panels at least. I just don't know what to do now that I have paralleled 6 total sets of 2 panels each!

Ultimately, as my picture above describes, I have paralleled 2 sets of 2 panels, three times, by feeding 2 pairs at a time into three 2 way splitters, then feeding those three 2 way splitters into a final 3 way splitter which eventually connects to the solar controller. I now have three values that I don't know how to work with: 5.72 amps, 11.44 amps, and 34.32 amps. Because of that 15 amp fuse rating per panel, I'm thinking -- based on my research -- that I should put a total of 3 fuses at the three cables coming out of my 3 way splitter. But then, even if that's the case, I don't know what size fuses to install, either.

Please, oh please, somebody help me figure out where along my connections I should put fuses, if necessary, and what ratings to have them be!

Thank you immensely,

William

Lots of good information on this forum. As such, I have been a lurker for quite some time, and have been able to answer most of my own questions without the need to officially ask them. =)

Unfortunately, I have run into a small snag, and just cannot figure out the math on this one. Seems like a simple problem, so hopefully it won't been too much trouble to answer!

Basically, I have 12 solar panels installed on my RV roof, each wired 2 to a series, then 6 strings of those 2 all placed in parallel with each other. The end result looks like this:

36V.png

I chose this connection method to both a) help me avoid the negative repercussions of shade, as I often deal with when parking my RV, but b) keep my overall amperage low enough to use 8 gauge wiring to my solar controller (from the 3 way splitter onward). Indeed, I could have gone 4 to a series, but because I had started with 2 each, and grew from there at a rate of 2 panels at a time, rewiring the whole shebang would be a nightmare, and I am trying to avoid doing that if at all possible!

So here's my question: where on earth do I place fuses in this setup, if any are even necessary? The specs for each of my panels (all identical btw) are as such: Maximum Power: 100W

Maximum System Voltage: 600V DC

Optimum Operating Voltage (Vmp): 17.9V

Open-Circuit Voltage (Voc): 21.6V

Optimum Operating Current (Imp): 5.72A

Short-Circuit Current (Isc): 6.24A

Maximum Series Fuse Rating：15A

So obviously, running each pair in a series keeps me under that 15 amp fuse maximum, per pair of panels at least. I just don't know what to do now that I have paralleled 6 total sets of 2 panels each!

Ultimately, as my picture above describes, I have paralleled 2 sets of 2 panels, three times, by feeding 2 pairs at a time into three 2 way splitters, then feeding those three 2 way splitters into a final 3 way splitter which eventually connects to the solar controller. I now have three values that I don't know how to work with: 5.72 amps, 11.44 amps, and 34.32 amps. Because of that 15 amp fuse rating per panel, I'm thinking -- based on my research -- that I should put a total of 3 fuses at the three cables coming out of my 3 way splitter. But then, even if that's the case, I don't know what size fuses to install, either.

Please, oh please, somebody help me figure out where along my connections I should put fuses, if necessary, and what ratings to have them be!

Thank you immensely,

William

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