The Importance of the EN 50539-11 Standard in Photovoltaic DC Surge Arresters

In order to protect solar systems against sudden overvoltage and lightning strikes, a Low Voltage Surge Protection Device (SPD) system must be used in front of DC, AC, and Data lines. TEDAŞ also particularly recommends the use of Class B+C products in DC combiner boxes. The selected products must have protection values against both the 10/350 ms lightning impulse curve and the 8/20 ms grid surge impulses. The use of DC Class B+C surge protection devices in the combiner boxes used in the DC sections of inverters ensures sustainable energy production for many years and is of great importance in preventing possible damages. Inside inverters, generally only TYPE 2 – CLASS C surge protection devices are installed. Unfortunately, these products do not provide protection against lightning strikes. If you examine the surge arrester characteristics in the manufacturer’s datasheet, you will see TYPE 2 – CLASS 2 definitions and protection levels. Therefore, Class 1+2 (B+C) products must definitely be installed in our DC panels.

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The quality of the product used is just as important as the product selection itself. The production and test standard for PV surge protection devices is EN 50539-11. Products that do not have this certification should not be used in our investments and projects. Non-standard products can cause more harm than benefit to our systems. Sudden overvoltage impulses occur in the range of 25 nanoseconds, and with non-standard products, these impulses may cause arc formation. Therefore, the products to be used must comply with UTE C61-740-51 and EN 50539-11 standards, and their certificates must be reviewed.

In product selection, besides standards and product type, product technology is also of great importance. VG technology products are capable of fast and unlimited damping. Therefore, our recommendation is to use EN 50539-11 Class B+C (Type 1+2) VG Technology PV surge protection devices in your projects. Correctly selected products ensure sustainable energy production and enable faster return on investments. PV surge protection devices require a distinct expertise. For this reason, many major companies have gaps in compliance with standards.

In conclusion, not only product selection and installation but also product quality and standard certifications play a crucial role in securing our investments. As Lightning Protection Center, we recommend verifying the EN 50539-11 certification for products used in DC sections of PV low voltage surge protection systems. You can always contact us for technical information about product supply and systems.