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gicamuci

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Posts: 7
Reply with quote  #1 
Hi everyone.
Currently I have 8 250w panels 4 in series and 2 strings parallel which are going to the MPPT charge controler.
I have other 4 250w panels in series that are feeding the MPPT controller for my solar pool pump which I think is not using all capacity on the 4 panels.
Assuming the Voc is the same (all 12 panels are the same model) on the two arrays, can I join the above arrays into one 12 250w panels 4 in series and 3 strings parallel and feed both MPPT controllers from this array ?
I want to jump from a 24v battery system to a 48v while doing this.

I hope it makes sense what I'm trying to explain.

Thanks,
Alex

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Hybrid 48V, FM80 CC, 16 x 250W ± 3 x 330W, 16 Trojan 105 Plus, 6KW inverter/charger

stmbtwle

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Posts: 3,028
Reply with quote  #2 
I don't think it's recommended to put two controllers on the same array, read the manuals.

However as controllers are rated in amps not watts, you may be able to go to one controller at 48v. Check your controller's specs, and see if you can do 2 strings of 6.

If not, you may be able to parallel both controllers (each on its own array) to 1 48v battery bank. Again, check the specs and manuals.

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Solar is like the wind. It may be free, but putting it to work isn't!
Willie, Tampa Bay
gicamuci

Registered:
Posts: 7
Reply with quote  #3 
I can't put the panels in 2 strings of 6 as it will be above the rated voltage of my MPPT charge controller 150V. My panels are 8.39A rated current and 37.6Voc

So I am limited to strings of 4 with the panels I have.
Raising the the battery bank voltage to 48V will allow me to add another 2 strings of 4 to the 2 strings of 4 I already have.

Most probably I will need to buy another 2 or 3 panels of 300W or higher to feed my pool pump controller and reuse the 1 string of 4 currently powering it, as a third string for my charge controller.

I will try the first option and see how the current will be shared by the 2 controllers from the same array of 3 strings of 4.
I guess the worst that could happen is one controller will use the whole current and the other will not work.

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Hybrid 48V, FM80 CC, 16 x 250W ± 3 x 330W, 16 Trojan 105 Plus, 6KW inverter/charger
stmbtwle

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Posts: 3,028
Reply with quote  #4 
Sounds like you have it.

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Solar is like the wind. It may be free, but putting it to work isn't!
Willie, Tampa Bay
gicamuci

Registered:
Posts: 7
Reply with quote  #5 
To update on this, I finally ended up adding another 3 x 330W panels and switched to a 48V system.
So now I have 16 panels (4KW) full time on my FM80 plus the above 3 panels on the pump controller, but with a twist.
Whenever I need/want, I can flip a switch and the 3 x 330W panels are added to the FM80 if sun doesn't cooperate and the pool pump is sure switched off.
I would like to automate this, but for now everything works perfect.

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Hybrid 48V, FM80 CC, 16 x 250W ± 3 x 330W, 16 Trojan 105 Plus, 6KW inverter/charger
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