Installers: Sunny Boy-US string sizing tool now available

From on 09/21/2016 in Category Technology with 8 Comments
SMA Quick Design Reference Tool

Designing systems with the new Sunny Boy-US just got easier and faster courtesy of the Quick Design Reference Tool. Simply input basic module criteria along with a few key system details to determine string design and inverter selection recommendations in a simple, easy-to-use and printable format.

Utilizing basic module criteria found on data sheets and some key details such as design temperature, loading ratio preferences and the AC output voltage, the Quick Design Reference Tool will calculate the optimum number of strings and modules per string, as well as the ideal inverter loading ratio (DC:AC) and model of Sunny Boy-US. This customized assessment can be printed for customer presentations or as a reference during installation.

Simplify and speed design time – download the free Quick Design Reference Tool from the Sunny Boy-US product page today!

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  • avatar

    Gary Koehler

    03/15/2017 at 9:50 am

    I have a Sunnyboy 700U inverter I am unable to get your online string sizing for this inverter for it will not accept my email addresses. Tried several. I have KC 130 solar modules. Temp range is 32F to 105F. I have 10 modules I can put on the system. Need to know how many max I can put on the inverter.

    Reply »
    • avatar


      03/15/2017 at 4:20 pm

      Try using You do not need to enter an email or create an account, just click on New project. You can enter your equipment type and it will give you string sizing based on your project location.

      Reply »
  • avatar


    06/27/2017 at 2:45 am

    i am Teddy from Ghana,Africa. I am an electrical engineer and a renewable energy consultant but am new into the use of SMA product. Can i get any training in the web design etc. thanks

    Reply »
    • avatar


      06/30/2017 at 10:53 am

      Hello Teddy, thanks for visiting us on SMA Inverted and learning more about SMA products! Please note that our SMA Solar Academy offers webinars. You can participate in these online trainings from Ghana and there are ways to interact just as actively as in our face-to-face trainings. To learn more, visit:

      Reply »
  • avatar


    11/25/2018 at 9:33 pm

    I’ve had SMA 25000TL-30 installed for over a year now but recently I’ve been seeing this abnormal spike in the energy graph on the sunny portal for the past five days. I was wondering if there was anything wrong with the system?

    Reply »
    • avatar


      11/26/2018 at 10:34 am

      Yousaf – It would be best to contact our Service Line to resolve this issue. You can look at the PV System Logbook on your Portal plant to see if there are errors being reported by the inverter.

      Reply »
  • avatar


    06/21/2019 at 3:50 pm

    My SWR 2500U is bust can I use the 3.8 US grid tie inverter to replace the SWR 2500U inverter? Konrad.

    Reply »
    • avatar


      06/24/2019 at 2:10 pm

      Konrad – you can use Sunny Design ( to verify if the array you have will work with the Sunny Boy 3.8-US. You also need to make sure the wiring from the inverter to you house panel is sized correctly for the larger inverter. Inspectors generally require sizing the wiring and PV breaker to the maximum capacity of the inverter, even if the array is undersized. That is to prevent dangerous situations from arising if the array is upgraded in the future.

      Reply »

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