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

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Treść została przetłumaczona polish » english Zobacz oryginalną wersję tematu
  • #1291 20046408
    slimax
    Level 17  
    It seems that when it is a cloudy day, the inverter cuts the power for short moments when the sun comes out from behind the clouds because on the module chains the voltage from the nominal Pmax 492V jumps to about 532V.
    SOFAR 8kW PV Installation: Opinions, Durability, Failures & Experiences with Inverters

    But in the case like today, when the whole day is sunny, the voltage does not reach the Pmax level, are the modules warmed up so much? Or maybe the inverter in the vicinity of the maximum power, to which it gradually comes, selects the operating point strangely?
    The recorded highest is about 484V, ie about 10% below the voltage from yesterday.
    Would he get anything more? Probably yes, but not much. On the next sunny day, I will unplug one string near the maximum power and check how much the inverter is able to squeeze out of half of the modules.

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

    Roof angle 40 degrees, south-east direction.
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  • #1292 20047623
    mentos2504
    Level 11  
    I have a Sofar 6.6 inverter and 7.66 kWp panels. It cuts me off too, but not much. In summer, on a hot, sunny day, it does not cut at all. Here's a chart to compare with yesterday. On the first day it was cut from 9 am to 3 pm, and on the second day, when the sun was shining practically all day, from 12 am to 2 pm. The panels are warm and the efficiency drops. Sofar has a program to calculate the number of panels. SofarsolarDesign1811. SOFAR 8kW PV Installation: Opinions, Durability, Failures & Experiences with Inverters
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  • #1293 20048459
    kosmos99
    Level 38  
    m2tk wrote:
    If a professional company and under warranty, I would advertise it because their task was to choose the optimal one, they would make you lose kW of production if it cuts it. Who selected the installation parameters? The installer should know that the 8.8 model cannot handle 10kWp.


    Just note that the manufacturers recommend oversizing, so there can be no complaint or lack of professionalism.
    Why do you write that the 8.8 model will not handle 10kW panels when the manual says that the maximum power of the panels is 12kW.
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  • #1294 20050187
    m2tk
    Level 13  
    kosmos99 wrote:
    Just note that the manufacturers recommend oversizing, so there can be no complaint or lack of professionalism.
    Why do you write that the 8.8 model will not handle 10kW panels when the manual says that the maximum power of the panels is 12kW.
    The manufacturer recommends (recommendation is not a requirement!) Oversizing because it is known that with 10kWp we will not get 10kW and the installation often does not have an optimal location (azimuth etc.) and hence the recommendations.
    Practice shows that since 8.8kW cuts with well-lit 10kWp modules, it is not optimal, although the maximum efficiency is achieved for several days a year, mainly in spring.
    12kW is the RECOMMENDED maximum power, with certainty due to the current-voltage protection. With poor elevation or azimuth NE and 20kWp, it will not be too high.

    Oversizing might still make sense, if the difference between the inverters was not in the range of PLN 200-400.
    Once the installer wanted + 2kPLN for the 2kW more power, then it made sense because mostly the truncations are negligible.
    If it cuts every day for a few hours, for me it is an assembly error (200 PLN / 2kW = 100 days of return).

    Added after 40 [minutes]:

    slimax wrote:
    But in the case like today, when the whole day is sunny, the voltage does not reach the Pmax level, are the modules warmed up so much?

    The panels lose their parameters with increasing temperature, e.g. -0.35% Pmax / ° C, where NOCT = 45 ? 2 ° C. When heated above 70 * C it can be even ~ 10% Pmax.
    Therefore, if it cuts even in summer, it will "cut" in spring all the more.

    For me, at 10kWp max in peak it was ~ 12.5kW (April 7),> 11kW happens often, while in continuous operation it rarely exceeds 10kW.
    Now in summer it reaches 9.8kW, and on very hot days only slightly above 9kW (June 3).
    The inverter 8.8 would cut this evenly almost daily.
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  • #1295 20050287
    kosmos99
    Level 38  
    From what is covered in most of the articles on this topic, this "clipping" is intended to compensate for the higher output of a less powerful inverter on less sunny days. The plus is that the panels will lose power over time.
    In reality, it will probably work for one thing.
    In general, my point is that in this case, a complaint due to too little flownik power is not an option.
  • #1296 20051096
    m2tk
    Level 13  
    Another issue is that in 5-10 years, electrics, heat pumps, air conditioners will come in as basic home equipment and then add these 2-4kW of power to keep the balance.
    At 8.8, we are already beyond the limit with an investment for 20-25 years ...

    For someone who has a balance sheet, it may be OK, but if someone spent PLN 30 on the installation and still has to (now) buy electricity that may be unsatisfying.

    PS:
    In the case of the installation from the entries above, things probably do not look so bad. Since summer does not cut, annual losses may be negligible.
    For me it would be unacceptable because I am already on the edge of the balance sheet.
    As if I have an agreement that with further expansion of the installation, the company will replace the inverter as needed at its own expense. At least that's what it is on paper, we'll see in practice in x years.
  • #1297 20051128
    Janusz_kk
    Level 39  
    There are two things, 1. if someone has room for expansion, he buys a larger phalanx, if there is no place and the installation is final, it makes no sense to buy a larger one, only 10-20% smaller than the power of the panels. Because after 1 maximum power, panels reach only in March and September, and the 2nd inverters have a lower starting voltage and optimal mppt, which means greater efficiency with less sunlight, after 3 panels, they lose power over time, so the periods of 'cutting' after a few years will not be.
  • #1298 20051703
    kosmos99
    Level 38  
    m2tk wrote:
    As if I have an agreement that with further expansion of the installation, the company will replace the inverter as needed at its own expense. At least that's what it is on paper, we'll see in practice in x years.


    It must be an expensive installation for the company to pay off. How many years is the maximum for expanding the installation so that they can replace the inverter at their own expense?
  • #1299 20052362
    m2tk
    Level 13  
    kosmos99 wrote:
    It must be an expensive installation for the company to pay off. How many years is the maximum for expanding the installation so that they can replace the inverter at their own expense?


    The cost is about PLN 3400 / kWp (6 optimizers). In the contract I had an old Sofar 10, but because they just didn't have stock, they gave a new 12.
    What I can see was a very good coincidence. I guess the exchange offer lasts as long as the inverter warranty (10 or 12 years).

    If not everything was so sweet, I will add that the assembly team was a bunch of patałachs. No project, go to the roof and eat.
    Halfway through the day I thanked them, they finished 2 days later with the manager but it couldn't be improved anymore.
  • #1300 20052497
    kosmos99
    Level 38  
    m2tk wrote:
    Cost about PLN 3400 / kWp (6 optimizers). In the contract I had an old Sofar 10, but because they just didn't have stock, they gave a new 12.
    What I can see was a very good coincidence. I guess the exchange offer lasts as long as the inverter warranty (10 or 12 years).


    The price is very low, if in a few years they had to replace the inverter for about 7,000, they would rather contribute to the business.
    It does not seem realistic to you?
    Especially now, when many people are expanding installations. So after a year or two, they have to replace the inverter with a larger one for free through no fault of their own?
  • #1301 20052567
    m2tk
    Level 13  
    That's why I approach it as for free . There will be something to be won - that's good, no - I will also survive it.
    At the moment, 10kW is enough for us, and yet the recommended PV for this inverter is 18kWp (sic!) - this is how much I do not have space on the roof.

    Someday, 6-8 panels will be added as needed or a second installation east-west.

    I don't think inverter prices will stay at these levels.
  • #1302 20069119
    LordZiemniak
    Level 15  
    Hi, https://www.sofarsolar.com/downloads here in the safety parameter section, new files have appeared, i.e. as before, after downloading, e.g. Sofar_3-12kw-G3.zip there was only version 005, now there is a new archive and version 006 is there , for Poland there are two files to choose from ... but I can not find order and composition what should I download for the KTLX 8.8 G3 inverter

    Sofar_3-12kw-G3.zip

    Sofar_7-11kw-G3.zip because the power range catches these two files ...
  • #1303 20069677
    m2tk
    Level 13  
    LordZiemniak wrote:
    Sofar_3-12kw-G3.zip
    This one includes a newer version:
    Sofar_3-12kw-G3 \ V06 \ safety \ 012-000- 0607 .txt (04/27/2022)
    Sofar_7-11kw-G3 \ V06 \ safety \ 012-000-0603.txt (03/29/2022)

    This 7-11kw is probably for 7-10.5KTL M. -G3 (single phase)
  • #1304 20069736
    slimax
    Level 17  
    Do you know what this update changes and is it recommended?
  • #1305 20083252
    behru
    Level 12  
    slimax wrote:
    Do you know what this update changes and is it recommended?


    Unfortunately, the manufacturer does not provide a list of changes in the update. All information comes from user observations. Theoretically, you could ask for the manufacturer's changelog, but I don't know if such a request will remain unanswered.

    As for the update recommendations, by following forums, topics and a little from my own experience, I can put forward the thesis that the update does not spoil anything and sometimes it improves something. An example may be removing (increasing) the production limit, faster reaching the maximum production after restarting the inverter, etc. Since the manufacturer in the next manufactured inverters within a given model gives a newer version of the firmware for the equipment that leaves the factory, it can be assumed that he knows what he is doing and can be updated ;-) The choice, of course, is up to the user :D
  • #1306 20099085
    wddd
    Level 11  
    Hello
    Have you met with such a problem with your colleagues?
    Sofar 3.3TL-G3 (1 phase) inverter new, used about four months. It worked very well but for about two weeks in the morning it won't turn on (not producing)
    Everything is fine, the display is on, the green LED is constantly on, but it only produces 10W. When I turn it off after DC or AC for a few seconds, everything returns to normal. It will happen from time to time that it will fire normally, like now on Sunday, but not yesterday and today. I have to go home and turn it off and on and it works great.
    Maybe someone has an idea for this problem?
    Regards
  • #1307 20099180
    prose
    Level 35  
    @wddd Check the AC voltages on the phase as you may have too high.
  • #1309 20099227
    prose
    Level 35  
    @wddd Well, check the MC4 plugs on the panels, maybe one of them overheated and the voltage gives a weak amp. I had so the production dropped, I went to the roof and it turned out that the connector had poor contact.
  • #1310 20099262
    wddd
    Level 11  
    Ok, but when I reset it (turn it off and on) it's ok, the power gives up to 3.3kW and the amps are also like it was before. In the Solarman application - device-inverter and at the bottom "bus voltage" as it is ok, the voltage is within 375V, but when it is within 415V, I already know that it does not produce then. I have 8 Risen 450W panels "
  • #1311 20142340
    prose
    Level 35  
    @toolpusher And what is your opinion about production after SW changes?
  • #1312 20173519
    m2tk
    Level 13  
    I have a question for experts on the subject.

    12KTLX-G3 inverter, I have the following items in the menu:
    1.Enter Settings -->
    --> 15. VoltHighLimit : 253,0V (ustawienie napięcia wyłączenia zwłocznego?)
    --> 16. OVP First:      264,5V (1 poziom wyłączenia bezzwłocznego?)
    --> 17. OVP Second:     272,0V (2 poziom wyłączenia bezzwłocznego?)
    --> 18. PowerLimit:     100% (ograniczenie produkcji mocy czynnej?)
    --> 19. ReactivePara: --> (produkcja mocy biernej?)
    ----> React: Enabled / Disabled: -->
    ------> React Mode: Power Factor (+000%) / Fixed Reactive (+100%) (w funkcji mocy lub stała?) 

    what can they be used for and how do you set it up?

    Does it have to do with too high mains voltage?

    The SOFAR service proposes to load the Q (u) - (option A recommendations?).

    Quote:
    Recommendations:
    To limit the shutdown of a micro-installation, you can adjust its settings. Only its installer can do this. He should first check whether its settings comply with European law [3] and the requirements of the Distribution System Operator [4]. If the settings meet the requirements and the micro-installation continues to shut down, the installer should enable the reactive power control function.
    It can run it in one of three modes:
    A) control of reactive power as a function of voltage at the generator terminals (Q (U) mode as the basic mode,
    B) control of the power factor as a function of active power generation (cos ? (P) mode) as an alternative mode,
    C) cos ? constant, adjustable from cos ? = 0.9ind to cos ? = 0.9 room, as an additional mode.

    The installer should check and select the mode in which the micro-installation will work properly with our network. However, if the reactive power control in any of the three modes does not reduce the number of micro-installation shutdowns, the installer should check the possibility of setting the operating mode:
    D) reduction of active power generated as a function of voltage increase (P (U))

    The micro installation will then limit the generated power, thanks to which the voltage in the Prosumer installation will not increase, and the micro installation will not switch off. This will ensure greater efficiency of the micro-installation. It is important that this function works only after exhausting the possibility of voltage regulation with reactive power consumption in Q (U) mode, ie above 1.08 Un. The installer must also pay attention that this function does not cause abrupt changes in the active power generated by micro-installations. "


    Does menu item 19. ReactivePara have anything to do with options B and C or D of the recommendation?
  • #1313 20174021
    Coll22
    Level 2  
    wddd wrote:
    Ok, but when I reset it (turn it off and on) it's ok, the power gives up to 3.3kW and the amps are also like it was before.
    In the Solarman application - device-inverter and at the bottom "bus voltage" as it is ok, the voltage is within 375V, but when it is within 415V, I already know that it does not produce then.
    I have 8 Risen 450W panels "[/quote

    I have the same inverter with 6 panels and had no problems. Export and upload the Excel file to check for invalid parameter
  • #1314 20176017
    LordZiemniak
    Level 15  
    m2tk wrote:
    I have a question for experts on the subject.

    12KTLX-G3 inverter, I have the following items in the menu:
    1.Enter Settings -->
    --> 15. VoltHighLimit : 253,0V (ustawienie napięcia wyłączenia zwłocznego?)
    --> 16. OVP First:      264,5V (1 poziom wyłączenia bezzwłocznego?)
    --> 17. OVP Second:     272,0V (2 poziom wyłączenia bezzwłocznego?)
    --> 18. PowerLimit:     100% (ograniczenie produkcji mocy czynnej?)
    --> 19. ReactivePara: --> (produkcja mocy biernej?)
    ----> React: Enabled / Disabled: -->
    ------> React Mode: Power Factor (+000%) / Fixed Reactive (+100%) (w funkcji mocy lub stała?) 

    what can they be used for and how do you set it up?

    Does it have to do with too high mains voltage?

    The SOFAR service proposes to load the Q (u) - (option A recommendations?).

    Quote:
    Recommendations:
    To limit the shutdown of a micro-installation, you can adjust its settings. Only its installer can do this. He should first check whether its settings comply with European law [3] and the requirements of the Distribution System Operator [4]. If the settings meet the requirements and the micro-installation continues to shut down, the installer should enable the reactive power control function.
    It can run it in one of three modes:
    A) control of reactive power as a function of voltage at the generator terminals (Q (U) mode as the basic mode,
    B) control of the power factor as a function of active power generation (cos ? (P) mode) as an alternative mode,
    C) cos ? constant, adjustable from cos ? = 0.9ind to cos ? = 0.9 room, as an additional mode.

    The installer should check and select the mode in which the micro-installation will work properly with our network. However, if the reactive power control in any of the three modes does not reduce the number of micro-installation shutdowns, the installer should check the possibility of setting the operating mode:
    D) reduction of active power generated as a function of voltage increase (P (U))

    The micro installation will then limit the generated power, thanks to which the voltage in the Prosumer installation will not increase, and the micro installation will not switch off. This will ensure greater efficiency of the micro-installation. It is important that this function works only after exhausting the possibility of voltage regulation with reactive power consumption in Q (U) mode, ie above 1.08 Un. The installer must also pay attention that this function does not cause abrupt changes in the active power generated by micro-installations. "


    Does menu item 19. ReactivePara have anything to do with options B and C or D of the recommendation?


    position 19 is just C setting permanently cos phi, order the sofar to upload qu and do not touch the rest ;) if the voltage in the network is ok, nothing will happen, and if it is too high, the qu function will dynamically adjust the cosfi to produce reactive power at the expense of active power, lowering the voltage
  • #1315 20176849
    andrew696
    Level 6  
    Hello. I have a question for the users of Sofar Solar KTLX series, does it sound a bit "buzzing" when the waves do not produce anything at night? It is hardly audible, but still, just bring your ear close to it ..... Earlier I had a disposable TL2700 G3 and it was completely noisy at night, even like the ear .....
  • #1316 20181241
    marwi123
    Level 12  
    Hello

    Does anyone know how to set / implement the export limit in Sofar ARPC to a specific value instead of zero, e.g. 20kW?

    Edit:
    I found
    arpc_configuration.exe and the usb / rs485 adapter
  • #1317 20182869
    toolpusher
    Level 23  
    prose wrote:
    @toolpusher And what is your opinion about production after SW changes?


    Sorry, I was not on the forum for a while. I would like to make sure that I am the addressee of the question?
    But if so, my 4.4KTL-X is like 6.6 with a 7.5kW installation without a problem. I also installed 5V fans powered by an inverter because my ceiling is quite low. And knock on for now. I'm going to drop off at 5.5, then on 4.4 and back in the spring. I was just a sucker because my router was dead and I replaced it with a new one and forgot to fasten the logger again. And I'm 4 weeks away from home and I'll have a production log gap. And I am waiting for the date when the installation will pay for itself. I did it myself, I have included the cost of materials. I will probably read from the inverter but there will be a hole in the app. I have a lot of consumption, because I have a crypto copy, so practically only in the afternoon hours I have overproduction, so I give back little to the network, which speeds up the return on the installation.
    Regards.
  • #1318 20182931
    marwi123
    Level 12  
    toolpusher wrote:
    prose wrote:
    @toolpusher And what is your opinion about production after SW changes?


    I'm going to drop off at 5.5, then on 4.4 and back in the spring.


    But why, if the startup parameters are the same?
  • #1319 20184005
    toolpusher
    Level 23  
    marwi123 wrote:

    But why, if the startup parameters are the same?


    I do not know. He deceives himself that if the inverter will fall, it will fall in the winter and the website will not go back as much in the logs. Alternatively, you will need to clean the memory card. Maybe they won't search on servers either.
  • #1320 20184037
    marwi123
    Level 12  
    toolpusher wrote:
    marwi123 wrote:

    But why, if the startup parameters are the same?


    I do not know. He deceives himself that if the inverter will fall, it will be in the winter and the service will not go back in the loagch so much. You will need to clean the memory card at any time. Maybe they won't search on servers either.



    I don't think they will have to analyze and browse. In the old sofara portal, the so-called 1.0 was the highest inverter power obtained ...

Topic summary

The discussion centers on experiences with Sofar inverters in approximately 8kW photovoltaic (PV) installations, focusing on technical issues, durability, and configuration challenges. Users report generally stable operation with models like Sofar 6.6KTL-X and 5.5KTL-X over extended periods, though some face connectivity problems, especially with Wi-Fi and software availability. A recurring technical problem involves input voltage exceeding the maximum allowed 600V DC for single-phase Sofar inverters (notably the 4KTLM-G2), causing errors such as PVOVP and BusOPV and inverter shutdowns. This is often due to too many PV panels connected in series on a single string, with 15 Q.CELLS Q.PEAK G4.1 305W panels sometimes exceeding voltage limits, especially in cold conditions where voltage rises. Solutions include splitting panels into two strings (e.g., 8 and 7 panels) connected to separate MPPT inputs, though some users report this does not fully resolve the issue. The maximum recommended panels per MPPT input is around 9 to avoid surpassing power and voltage limits. Users also discuss the need for three-phase inverters for larger installations above 7kW on a single phase due to grid operator restrictions. Software and firmware updates are sought after but not easily accessible, with some users lacking Polish language support. Comparisons with other brands like SMA and Fronius highlight Sofar's cost advantage but raise concerns about long-term reliability and service support, which is still developing in some regions. Network-related errors such as Grid OFP (over-frequency) have been reported, with troubleshooting involving network frequency checks and inverter restarts. Overall, Sofar inverters are considered a cost-effective option with some technical caveats related to system design, installation quality, and support infrastructure.
Summary generated by the language model.
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