Mppt controller help
- Thread starter gaza2015
- Start date
Zwy
Solar Wizard
What is the VOC of the panels?
wiseacre
Solar Addict
x 4 = 180.56 VOC
A 4s string is way too high for a 150/50 SCC
2s2p array would be fine though
For a 150 volt MPPT controller and a 48 volt inverter, you would like the voltage coming in to the controller to be at least 64 volts. So if you have 400w x 4 panels at Voc of 45 .15 volts, then 2S2P arrangement will provide roughly a Voc of 80 to 105 depending on ambient temperatures. This is excellent for the MPPT software of the controller to charge the batteries which probably have an absorb of around 56 to 58 depending on the type of battery.
3s at 45.14V VOC is still very close. What’s the historical coldest these will ever see, -20f?
Toss up the exact panel and spec sheet.
BryceFreeman
Ecoworthy Distributor
Agree with all above. 3x45.14=135.42, still too close to the rated volt. It's not a good choice. To keep the controller working at high volt will consume its life quicker. 2s2p is indeed a better idea.
VOS isn’t VMP, so the unit won’t be working that high so that isn’t the issue. It needs to isolate current or initiate current.
IMO if this guy is in FL I’d have no issues running 3s with 150v. In NH I’d only run it in a 3 season camp.
timselectric
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With 4 panels available. 2s2p is the best choice.
He corrected and implied he only had 3 panels, not 4
timselectric
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Actually, they said "3 string". Not even sure what that means.
Not sure about 2s2p not clue want that means
timselectric
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2s2p
Two panels in a series string. (2s)
Two strings in parallel. (2p)
Two panels in a series string. (2s)
Two strings in parallel. (2p)
The first 2 series panels would be 33amps the parallel 2 would be 66amps which is 96amps is that right
timselectric
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No
Two panels in series. (A series string)
Voltage is added together and amperage stays the same.
Repeat this for the other two panels.
Then put the two series strings in parallel.
In parallel, the voltage stays the same. And the amperage is added together.
The end result would be (according to the panel label), 2 x voltage and 2 x amperage.
Would it be wired like this
timselectric
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Yes
