Just keeping their existing Midnite Classic 250. It's pretty beat up at this point, hums like crazy and the screen craps out all the time, but I think I'd like make that a separate project and avoid upgrading multiple things at once.
For the breakers in a combiner box then I'd want to multiply by 1.25 right? So the 12.68 x 1.25 = 15.85A. That could maybe work with 15A breakers but to be safe I should upsize to a 20A breaker?
So in this example, the combiner box should have 2x 20A breakers and the wire leaving rated for 40A.
Curious why you said "you can't have 3 series strings of mixed panel types" from what I've seen I can mix panel types, as long as the resulting voltages are near enough. The voltage will drop to the lower of the strings' voltage though, which I accounted for in my calculations by assuming amps...
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Well then that is just luck, I never knew about that being an issue, I thought the only thing I needed to line up was the total Voltage for each string type.
That does look great, and like my current MidNite Classic 250v MPPT, it doesn't even mention max input amps or watts in their spec sheets, seeming to imply that there is no issue with extreme over paneling?
Is it just that MidNite solar is better designed than Victron/Morningstar? Or maybe...
I have panels that at a maximum would be max 67amps and 80amps including bifacial. The Ampacity chart shows that 80 is a bit close to 75c. Additionally, my calculation is that I would see 10.09v 8% voltage loss across the 300 feet from panels to Midnite Solar Classic 250 MPPT charge...
Thanks, You were correct that 8 in series VOC would go over the max VOC for Midnite Classic 250. Likely will stick with the inefficient 4 panels in series for now until other parts of the setup can be fixed.
Thanks, didn't realized I missed adding that, will add it above as well.
Name
Strings
Series
Panel Count
VMPP
Volts From Panels
old panels
2
4
8
36.5
146
new panels
4
4
16
34.71
138.84
Right, currently both are in groups of 4 and I would also prefer to increase the voltage.
The first logical reason I had trouble with that 4 of the old panels are up on a tall pole mount, my uneducated assumption was that with 4 up in a group, I couldn't include those 4 in a series with other...
Yeah, I like the look of the Victron 450/100 too, also looks like their external measuring ecosystem (like apps, exporting data etc) is good too.
You mentioned that you have 20 AMPS each, but when I was looking at their spec sheet, I thought I should be using the 18 A per tracker based on "Max...
It's pretty tempting to just choose this one, I don't know why they don't list the max input Amps or Watts but it feels like it's OK versus the other three (EG4/Morningstar/Victron) that make it seem like going +30% is a line that shouldn't be crossed.
All three of you have the same recommendation, voltage up and amperage down. Is it possible to do with 4 panels on the pole mount and the remaining 20 in 3 strings of 8 in series nearby? The issue is that one string would have 4 panels on the pole mount, 30' wires, then the rest of the 4 in series.
Thank you, I didn't know to check the ISC is under the 22A max input amps, but I'm confused because I thought I could over panel long as the max Voltage is respected. For example this user from another thread...
I'm OK with brand, and they seem to have similar specs, but just confused about whether I can safely overpanel over the 22 max short circuit input amps or if that is dangerous. Given that my current panels are 12.88 ISC each, it would seem I could only ever have 1 string as any more would go...
Looking closer at the specs for Victron and EG4 they both mention that the danger is if the polarity is reversed:
So I guess having a higher PV input Amperage is OK as long as I don't ever mix up the polarity?
Thanks, that's a good idea, so I just went ahead and did that. It also does not seem to recommend any over paneling. Basically just a maximum of 1 string. It doesn't even try to estimate for 3 strings.
The dark color for 10 modules + says:
I am trying to calculate the max amps for breakers and for wire guage estimates, but I realized the way I was calculating it for bifacial lead to some questions.
First, is it correct to calculate max amps leaving panels as watts/voltage? While this makes sense for the rated 440W, for the...
I have 16 panels that I can arrange on a single large array. There are several tree shadows that are present in the Winter during the morning until 11AM. The panels are facing south, and the shadows pass from the left to the right, with some shadows only touching the right.
Given this, which of...
It's midway through intersolar but I don't really have any way of following the news. Any good coverage of it?
I'm looking forward to hearing if there are any new products or releases.
So far I've seen this...
Apologies, I'm not currently at my parents home where this is going to be done, so can't get a more straight forward pic. Panels in field, dog for scale ;). Combiner box in middle of panels goes to where picture is taken from, buried 4 AWG.
This is the current setup. Currently there are 8...
Ah, I didn't explain well, there were just two options there, the 2S8P in two rows or 2S8P in two 'squares'. Then the other two pictures were visualizing the shadows are various times.
Since any amount of shade on any panels kills it then I guess more bunched together is better.
Actually, I went a bit quick above the 3 series of 8 is in fact too high of voltage for the current Midnite Classic 250 MPPT Charge Controller, though I could do several strings of 6:
Name
Strings
Series
Count
VMPP
Volts From Panels
Watts
Max Watts
Amps by Lowest Voltage
old panels
1
6
6...
I'm looking for a new charge controller that can handle max VOC > 470V. So far I've found these two models, but they have a very different set of prices, so I'm not sure if I'm missing something that the Morningstar has that the EG4 does not.
$989 - 600V - Morningstar Tristar DB TR GFPD
Comes...