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trevor-1 avatar image
trevor-1 asked

mppt 450/100 individual string production not adding up to total production in vrm dashboard.

Hi Guys

Got my solar system about a month ago so I am fairly new to this solar thing and have alot of questions around my setup.I have learned alot from previous posts on this community but will probably be asking alot of questions in the near future.

Setup is as follows

3 x Multiplus2 48/5000/70-50 1 master 2 slave

mppt RS 450/100

3 x BYD Flex 5Kwh Batteries

23 x Ja Solar 415W panels.String 1-11North facing String 2 -12 west facing.

So my first question is,looking at my current setup I get the feeling I am waisting alot of yield from the panels due to the 100 A limit on the mppt which is seeing me get a max usable yield of about 5300-5500W.So my plan is to change the 450/100 for 2 x 250/100 daisy chained together to facilitate sync.Would this be a good call as In my mind that will alow me to draw 200 amps at 55V which would be 11 KW of solar in theory.I know my panels wont get their for now but would like to leave room for expansion.

My second question is why am I seeing about a 10% loss from individual string production to total production(see photo)I am loosing about 500-600 w/ hour.If I add the PV strings yield together is is less than the total displayed in the pv charger.

Thanx in advance

Trevor

vrm.jpg


MPPT Controllers
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klim8skeptic avatar image klim8skeptic ♦ commented ·

23 x Ja Solar 415W panels.String 1-11North facing String 2 -12 west facing.

11 of These JA solar panels in series is well over the mppts PV voltage limit of 450v.

Plz check panel model number.

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trevor-1 avatar image trevor-1 klim8skeptic ♦ commented ·

screenshot-20221231-162712.pngIm sure some are in parallel exactly how the installation is setup Im not sure but can find out from installers once they open again.The max voltage im seeing for S1 is about 238v and for S2 about 300v.Hope this helps

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screenshot-20221231-162712.png (176.0 KiB)
trevor-1 avatar image trevor-1 klim8skeptic ♦ commented ·

screenshot-20221231-162712.pngIm sure some are in parallel exactly how the installation is setup Im not sure but can find out from installers once they open again.The max voltage im seeing for S1 is about 238v and for S2 about 300v.Hope this helps

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3 Answers
JohnC avatar image
JohnC answered ·

Hi @trevor-1

By those production figures you actually have 4x parallel panel strings. 2x into each tracker (The trackers called 'Strings' in the reports). This raises the question whether the 11x is split into a 6x and a 5x, or two 5x strings with one left unwired. Neither outcome a great look for the installer.

The 250/100's not a great option, as they're likely unsuited to more than 4x of those panels in each string.

What you should really have is a 450/200, with 4x trackers. Indeed the existing setup exceeds the solar Current specs for a 450/100, and probably void warranty if anything happened. https://www.victronenergy.com/upload/documents/Datasheet-SmartSolar-MPPT-RS-EN-.pdf

If this lot was sold to you as a turnkey job, you'd be within your rights to demand a 450/200 as a replacement. Your production issues then solved.

Your future expansion of this system maybe only with an increase in string length, perhaps to 8x/string.

I wouldn't worry too much about the reporting totals. There's efficiency losses in the mppt, maybe measurement tolerances, and even misaligned reporting times that can impinge there. You have bigger issues.


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reginald-potts avatar image reginald-potts commented ·
I disagree completely. Do not go for a single 450/200 controller, it might solve your particular problem but if anything goes wrong down the line you lose ALL your power. Much better to spread the arrays across several controllers in sync (at least two) so you only lose half/ third/ quarter of the available power should a controller fail. Price wise 2x 450/100 are same price as 1x 450/200.
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trevor-1 answered ·

Thanx JohnC for the input.l will have to get clarification from the installer on this matter so as to get this setup sorted out.


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trevor-1 avatar image
trevor-1 answered ·

Thanx JohnC for the input.l will have to get clarification from the installer on this matter so as to get this setup sorted out

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