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Overview of Over-paneling an MPPT controller

Overview of Over-paneling an MPPT controller 2023-01-05

This a good resource. Thanks
I had a half-right idea how to do this-- I was aware of the Voc limitation but could not find a clear answer to how an SCC handled higher incoming amps. This document helped me determine how to reconfigure my system in a way that made it more productive and minimized the $$$ spent on additional components. Thank you!
Very nice info regarding over paneling.
I deducted 1 star because it needs more data on different units.

I just ordered a small 1000W 12V mppsolar unit (PIP1012MSE) that has a Max PV VOC input of 105.
It took some digging but I finally got an answer regarding Max PV input current and it's - 50A - so very safe to over panel it quite a bit.
Super nice since we live at 63˚north.
This has been an excellent resource! Thanks. Has anyone heard feedback on just putting a fuse in series with the input?
Thank you for this excellent resource, I've learned a great deal from it.
There are sone typos in this sentence on page 6: "Consequently, THE A limit on the Array Isc is most likely to be a limiting factor when the Voc THE OF PV Array is at the lower end of the operating PV voltage for the controller. "

Two sentences further on: " to produce a Voc that is higher
in the controller’s safe operating range" - should that be "higher THAN"?
FilterGuy
FilterGuy
Thank you. I fixed the first and clarified the second.
Thanks a lot.
Am I correct in saying there is one error in the guide or maybe I'm reading it wrong. On page 17 it says "However, the array Isc
would be 5.86V x 8 = 46.88V. " Shouldn't it be 5.86A x 8 = 46.88A? A great bit of info though.
Thanks for the excelent paper, do you know if tne MPPSolar PIP3024MSXE allows overpanelling? I think it does not as the Voc seems a hard limit. This is the manual: http://www.mppsolar.com/manual/PIP-HSE,MSE_HSE1,MSE1/PIP-HSE_MSE%20manual%20(PF1.0)%20-20190717.pdfV
A great overview of how overcharging can be an asset within reasonable parameters. Thank you!
Great paper!
As usual, Filter Guy nails it! Thanks for including the Growatt info. I was wondering about that.
This is really a good paper!
Thanks for this. I am thinking about Way Over-Paneling a Classic 150 soon.

I am making a post about what I want to do and would appreciate any feed back so I do not make a huge mistake. I have not ordered anything yet.

https://diysolarforum.com/threads/over-paneling-a-3s3p-to-3s5p-with-slightly-different-panels-advice.29838/
Very usefull. Just a comment: victron states in their manual:

There are two limits, when determining the maximum array size that can be connected to an MPPT:

The Maximum PV open circuit voltage (Voc at STC)
The Maximum PV short circuit current (Isc at STC)

-> so so max overpaneling on victron MPPTs is most limited by the short circuit current. You can find the Isc at STC in every MPPT manual. One thing is interesting: the short current is the same for one series of MPPTs. e.g. 150/45 to 150/70 -> all have 50 amps max PV short current.

Jens
FilterGuy
FilterGuy
Previous Reply was deleted and replaced by this.

After additional research and communication with Victron, it has become clear that the Max Isc spec comes into play in more scenarios than just reverse polarity on the PV inputs. Victron has declined to elaborate on the additional scenarios but has made it clear that the scenarios exist. So, even though Victron has called the Max Isc spec a 'Soft limit' the designer has no choice but to treat it as a hard limit.

I have updated the resource to add pages with Victron specific information and how to deal with the Max Isc spec.
Good explanation and graphics.

Over paneling works with my VIctron 75/15 MPPT. I use 600 watts of panels to over-panel my 360 watt SCC and move the panels along with the sun to max charging.

I limit charging to 14 amps due to BMS limitations. For me, I want my panels to replace energy a 300 watt load consumes and still have a little left over to charge the battery.

Overpaneling does work in this application.
Extremely helpful for a confusing topic. Thank You!
Concise, easy to follow. Puts the topic to rest
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