SOFAR 8kW PV Installation: Opinions, Durability, Failures & Experiences with Inverters

Well, you have exceeded the maximum voltage on frosty and sunny days http://solar-tech.pl/wp-content/uploads/2017/07/QCells-290W-305W.pdf, i.e. about 608 V and the inverter will not start http: / /www.sofarsolar.com/product-detail/459/SOFAR%204KTLM-G2 detach 2 panels or divide into 2 chains one 8 panels the second 7, try 1 option first, because the second is additional cables and protection must be installed. Give me more photos of what '' Miszcze '' has installed

Added after 7 [minutes]:

PS
To disconnect the panels, you need to turn off the inverter from the AC mains and wait at least 5 minutes then the DC MC4 plug so that it does not kill you, or call an electrician because it is better not to bury yourself with this voltage, and you must advertise because in this option it may cause a fire (and are surprised that UDT will need to connect the installation)

iwostar wrote:

It does not look like there are too many panels, because in summer itself it worked normally on sunny days, and it can turn off on a cloudy day, although I think it may be affected by the sudden departure of strong sun from outside the clouds.

It looks to me that the problem is with the network. 4kW goes to one phase in the absence of reception, the voltage increases in this phase and hence this BUSOpv error.
There are no new installations at the neighbors?

DTR error description

What do you think about replacing the inverter with a more powerful one? I plan to put another 8-9 panels on the shelter in the spring, this one would come in handy then.

I will try to connect an energy-consuming receiver at the time of the error. We'll see if it will change anything ...

Nothing has changed with the neighbors lately.

the receiver will not help, it was necessary to buy a larger inverter and connect 2 strings 15 and 9 panels, about 6000w-8000w
so that the string supports about 4000 in

And one more question, how far from the main switchboard you have the inverter connected and what is the cross-section of the cable to it

I think that it is unnecessary to consider replacing the inverter with a more powerful one, unless in terms of not the power but the input voltage, because the problem here is the DC input voltage, as indicated by the displayed errors
This inverter has two inputs so why not split this 15 panel circuit

I have to find a specialist in the area who will undertake such a modification.
I think that the purchase of a more powerful inverter would also make sense when investing in a second set. It seems to me that two inverters are a safer and financially similar solution, as one powerful for two sets.

iwostar wrote:

in the summer itself, on sunny days, it works normally, and it can turn off on a cloudy day, although I think it may be affected by the sudden exit of the strong sun from outside the clouds.

A panel heated to 55C (for example RSM60H-156PE, others are similar) generates a voltage to almost 4V lower than a panel cooled to 25C at the same sunlight and operating current.

Do not call a specialist, but the company that installed it for you. Tell them you know what is causing it. Have them come and split the panels into two strings (8 + 7).

I do not plan to cooperate with the company that installed the kit for me. They turned out to be bunglers. In addition, I have not received an invoice for the inverter, panels or warranty cards from them. Financially, the topic is also partially unregulated, but they prefer to leave it that way.
In the spring I plan to install another 10 panels, and probably by the way a chapter of the current set will be made, as you suggest.
The equipment is currently working. Inverter errors and stalling occur only under certain weather conditions.
Thanks to everyone for the advice so far!

you didn't get the papers when you connect the meter

Added after 1 [minutes]:

you need to warn against this company as it was called

I got the papers for PGE. I have a counter for a long time.
The company's bungling consisted of:
1. They could not count how many panels would fit on the roof slope intended for the panels and had to order and reassemble additional panels.
2. During the first assembly they did not use a spirit level or any measure. The panels were at different heights (keyed) and above the top of the roof. They had to rearrange everything the next time they visited it to comply with the rules and levels.
3. They couldn't count the right inverter and changed it in the meantime. As it turns out, it is still not suitable or properly connected.
The company GlobalSun - Sanok.

If you want, write wgrzeziu(_at_)wp.pl

Added after 3 [minutes]:

DUAL MC4 connectors - PV parallel connections.
Buy something like this on Allegro, connect 2 pluses in the inverter so that 1 end of the inverter comes out and do the same with the minus - you will bridge mp trackers and get full power and it should be git

Thanks again! Wish you live closer

Human Tuszyn

After all, the parallel bridging of the inverter inputs, which is proposed by the col.Grzeziu, will not reduce the voltage of the string which consists of 15 panels connected in series, the voltage at certain temperatures will still be too high

But 2600 W is provided for 1 string, then either separate the panels either like this, or 2 pages as it was written, e.g. 8 and 7 and it comes out the same

Separate the current panel string into two circuits and connect each to a separate MPP input
And it is not the same as connecting the current string to the inputs connected in parallel

By dividing the wires into 2 strings and additional protection, it is best to make 1 string of 8 panels and see what will happen

Buddy Grzeziu, you were not right, unfortunately. Separation did not work ...
When the voltage reaches 600 V, the inverter is turned off. Question for experts: will the inverter actually "pull" 15 panels? Could there be any other problem?
In the spring, my idea was to connect 10 more panels to the second circuit, and here it turns out that 15 of them are too many and they will have to be separated ...

I have 28 panels connected to one inverter, each 280 W panel, 18 and 10 panels on each string, on one approx. 630 V, nothing is happening,

Added after 2 [minutes]:

If you separate the panels or unplug a part, you will not reach 600 V on 1 string, there is no chance.

I understand you have a more powerful inverter. The ones I found on the SOFAR have a limit of 600V.
A question for professionals: can the SOFAR 4KTLM-G2 inverter "pull" 15 PV panels Q.CELLS Q.PEAK G4.1 305 MONO BLACK?

It is strange to write how you separated these panels, because if they would work at max, you would slightly exceed 600 V.

grzeziu, no offense, the question is for professionals.

iwostar wrote:

I understand you have a more powerful inverter. The ones I found on the SOFAR have a limit of 600V.
A question for professionals: can the SOFAR 4KTLM-G2 inverter "pull" 15 PV panels Q.CELLS Q.PEAK G4.1 305 MONO BLACK?

For this inverter, you have to meet a total of several conditions for each MPPT:
1) min V DC: 120V
2) Max V DC: 600V
3) Optimal V DC: 360V
4) MPPT V DC range: 90 -580V
5) Recommended DC voltage range for one MPPT: 200V - 520V
6) Max I on DC: 11A
7) Max DC power for single MPPT: 2600W

Your PV panels at STC May:
9.35A and 32.6V

If you connect them in series to one MPPT in the inverter then:
15 * 32.6 = 490V and the same with the current, so here it is OK but you exceed the allowed power for one MPPT, so the maximum that you can connect to one MPPT is 9 panels (9 * 305W = 2750W> recommended 2600W but these are the conditions for STC, so practically impossible to achieve in real use)

If you plan to add another 10 panels, then with this inverter you will not succeed ... you will exceed the power for single MPPTs, so the maximum what you can do with these panels are two chains with 9 panels per string.

BikeBarian, thank you very much for your explanations!
In the context of this, it is difficult for me to understand how the company that assembled the kit made a mistake and how this kit works in general, because errors and disconnection occur only under certain conditions.
Which inverter from, say, SOFAR would be suitable for me, so that there would be no need to separate the existing panels into two systems, and in addition, you could think about adding another 10 pcs?

iwostar wrote:

Which inverter, let's say, from SOFAR, would be suitable for me, so that there was no need to separate the existing panels into two systems, and additionally, to add another 10 pcs?

If you want Sofar then: sofar-8-8ktl-x

kosmos99 wrote:

iwostar wrote:

Which inverter, let's say, from SOFAR, would be suitable for me, so that there was no need to separate the existing panels into two systems, and additionally, to add another 10 pcs?

If you want Sofar then: sofar-8-8ktl-x

And 3-phase connection. 8kW and you wrote about 4.5 and 1-phase.

On the stubborn with 24 panels, the 305W Sofar 6KTLM-G2 would pull two strings of 12 panels each, but you probably have a 1F inverter now, so such a change would probably not pass because the OSD more than 3600W per phase is no longer released. You would have to give a larger inverter but then 3 phases or stay with it (and change the number of panels in the string) and add another 1 phase inverter for the second phase.

So with the current installation, changing the number of panels to a string and if you add another 10 panels, you will still have to switch to 3F because over 7Kw on one phase no OSD wants.