Nuno Donato

Hi folks

I thought some of you might be interested in this :)

https://www.nunodonato.com/2021/11/20/using-a-telegram-bot-to-help-me-manage-a-solar-off-grid-setup/

since I got down from 9 to 8 panels, I wonder if its worth to reconfigure my setup
from: (3x300) + (3x+300) + (3x300)
to: (2x300) + (2x300) + (2x300) + (2x300)

I need to get new cables for that and re-do some wiring... is it worth it?

Eric Hanson wrote:Does this confirm the problem is the string and not the panel?

Well, for me the problem is the panel, once I took it out, the rest seems to be working

Update!
With only the bad string connected, I took out one of the panels and I think I got lucky right on the first one! I tried to connect the string with 2 panels to the inverter and it began charging! So i guess I found out the culprit.

Is it worth to open the panel's "box" and look into some possible issues I can fix? Or is it good to replace? (its only 2 years old :( )

Thanks everyone for the suggestions. This is a 48V system with 48V batteries.

Since my multimeter clamp is AC only I'm out of luck testing that.
But I did run my own cables to the MC4, so I'm going to check those out first.

Eric Hanson wrote:Is there a way to unplug the panel and test for overall wattage?  Maybe run some lights directly from the panel to get an idea if it is producing full amperage?  My thinking is that it could be producing adequate voltage but tiny amperage and thus low wattage.  Maybe this would work?

These are 48V panels... I dont think I have anything that I can plug to it directly... :/

Eric Hanson wrote:Do you have an electrical multimeter?  As in voltmeter and especially amp meter?  In this case a clamp on meter would be ideal.  

What I am hypothesizing is that one panel is producing sufficient voltage but for some reason insufficient amps.  A clamp on amp meter could answer this hypothesis quickly.

Just a thought,

Eric

I have a clamp meter but it says AC all the time and I cant seem to make it switch to DC. Any other way to test the amps?

S Bengi wrote:It sounds like once it's underload, one of those panels stop working.
So the next step world be to test each solar panel with a load to see which one of them fail.

Not sure how I can test each panel individually, because it wont give enough voltage for the inverter to start the charge.

Do you have any 24Vdc to 30Vdc load around the house?

Everything everything is 220v. Not sure what you meant

Hi folks,

Yesterday I noticed my production was 30% down from the usual. I have 3 strings of panels (3x330w each). Each string has the 3 panels in series, to get to around 110V, and then they all connect in parallel to my Axpert Inverter.

After some quick diagnostics, I found out one of the strings was not giving any power to the inverter. (I realized this by disconnecting one by one, and noticing that this one did not make any difference being unplugged or not).

I spent most of my day trying to check the cables (some of them underground), and making sure there was no connectivity issue. I tested connectivity with my multimeter and everything seemed to be ok (I did not want to dig the underground cables...)

I checked the voltage of this particular string, and it was ok at around 110V.

Today I tried something else, and this is when things begin to get weird.

I disconnected completely the 2 good strings. I measured the voltage of the bad string before connecting to fuse box+inverter. 110V as expected.

Once I plug things on, the voltage drops to about 50-60V, and the inverter is not able to "connect" the charge (it does this "click" sounds every couple of seconds).

I'm lost trying to understand what this might be. Please let me know if you have any ideas. I really do miss those precious 30% now in winter time :(

Hi folks!

Being a bit techie and offgrid with solar, I installed a simple solution to log all the data that my inverter outputs on a 15min basis (pv production, power load, battery voltage/capacity).

Because my wife doesnt deal with the inverter, I made a simple webapp where the data is displayed "live" (15min delay at max), along with records of the last hour and a chart that allows you to see everything on any day you choose. This is pretty cool, but not polished since its just for us.

I was wondering if others might see value in a simple solution like this. I was thinking of setting up a small online service for a symbolic fee(5$ a month or so) to host the data for everyone else and then have a nice but simple interface to check live data and charts.

Is this something interesting? Will it have an audience? I know that some brands already have their own cloud offering, this would be for all the other inverters that, like mine, are not that "smart" ;)

(tech notes: in order to upload the data, I bought a simple raspberry pi zero that connects to the inverter via usb, and via a script periodically sends the data to my webapp. this part will always have to be solved by each person individually according to equipment, etc..)