Hi guys.
I’ve had a solar system installed and have had a multitude of problems.
But the last one is the one I’m having problems with. When the inverter was tested mppt1 took several minutes to turn on and mttp 2 turned on straight away. The guy that came to inspect and sign off on it flagged it.
The fronius IT said its fine and they will monitor it but I believe there are problems straight away. First full day on was sunny not a cloud but it only just touched on 4kw and only briefly. The system is 19 panels 7.79kw with a 6kw fronius primo
Here are pics of the mttp charts. It doesn’t look right to me. Value opinions please.
Post pics and stats for power as well, not just voltage. Full set of stats from PVOutput would be great (you can just post a pvoutput link to your system). Compare to other systems of similar size in your area.
Voltage can vary between MPPs, it can show nearly identical chart or it can show fairly un-synched values depending on the day. Panel orientation and shadowing (trees, chimneys, roof eves etc) will also play part. Here’s a couple of screenshots from the same system on different days.
Thanks for the reply. Does this help.
It just doesn’t look right to me.
bit hard to tell from the photo of the screen.
Can you separate them so MPP1 is in one image and MPP2 is on a second image?
And preferably snipping tool it?
13/5/22 is definitely something weird going on with mpp1 would like a better photo of this one.
it looks like when the voltage dropped you got more power from it???
14/5/22 looks like shadowing… maybe a few panels were bypassed?
15/5/22 looks acceptable
is there any errors on the inverter or in solarweb? id almost say a drop in power could be caused by a grid overvoltage… that might raise the voltage of the panels…?
I haven’t really studied my data on solarweb to know what certain things do.
What orientation is mpp1 and mpp2 facing?
is there any shade? trees chimney etc…
Give us as much information as you can about the system as you can.
I can only access that data for 3 days as I don’t have premium so those are the only snapshots now of those moments.
There was a inverter issue at time of compliance and mppt 2 would turn on instantly but mppt1 had a several minute delay.
The installers came back today and realised the orientation was wrong so they’ve fixed that. They have also connected up the panels on the NE roof to mppt2 and the 3panels on the east roof to mppt1 and see how that goes. Couldn’t tell as it was a cloudy day and we are heading into winter. But I might have seen a improvement but won’t know to we get another sunny day.
orientation was wrong?
only 3 panels on mppt1?
how many on mppt2?
so no errors showing then?
I’m running LG 410w panels.
3 are now running on mppt1
16 are running on mppt 2
By the time they finished it was clouding over and the yield drops them anyway so I can’t compare fully now until I have a good sunny day.
Do you think it’s ok to have that many panels on one string?
I suppose ideally the strings would be ‘balanced’ to even out the load and wear and tear but the critical thing is that the entire system is running within its design specifications.
Fronius’ website provides the INPUT DATA for the 6kW Primo including MAX INPUT Current 18A and MPP Voltage Range 240-800VDC
also note if this is residential you need to be under 600v open circuit voltage.
do you know your panel model numbers? the DC voltage doesn’t really seem too much different considering 3 are on one mppt and 16 on the other.
im guessing its 1 string of 3 and 2 strings of 8
but looking at the power chart on 13/5 mpp1 is doing about 1400w and mpp2 is 2600w which just doesn’t make sense in that string arrangement
3x 410 panels cant do 1400w
and if it was split into 1 string of 8 on mpp1, 1 string of 8 and 1 string of 3 on mpp2 it wouldn’t be nearly double
can you screenshot the error page please!
https://www.solarweb.com/MessageCenter/ServiceMessages?
I hope this will send you to your direct link
3 panels are struggling to supply enough voltage and the MPPT is constantly hunting. That string needs more panels to be viable.
No issue. It would be normal however for them to be in a 2 x 8 configuration, i.e. 2 strings of 8 panels in parallel.
https://creator.fronius.com/ says that 3 strings are fine… but that’s without knowing actual LG panel specs just using any LG 410w panel spec
