Install and safeguard PV systems on the roof

Products for rooftop PV systems

Product overview Surge protection for PV systems

• What are the special features of PV Next combiner boxes and how do I find the right variant?

  A PV system on the roof requires an IEC 61439-2-approved GFCI to protect the system against overvoltage. The Combiner box PV Next also offers additional functions, such as the bundling of strings for reduced cabling effort. Depending on the installation type, overvoltage protection Type II or Type I+II is required. You can easily find the right variant using the selection guide on our website.

  Learn how to choose the right PV combiner box in our fact sheet
• How do you protect PV installations against lightning strikes?

  The overvoltage protection inside a PV combiner box (DC side of the installation) is one part of the lightning protection system (LPS) of a building and is mandatory according to EN 51643-32 in the EU and beyond since 2019. It is used to protect your PV system and the electronic inside the house against overvoltages.

  You can find detailed information on surge protection for PV systems in our fact sheet

• When are DC fuses mandatory to install?

  Depending on the kind of photovoltaic installation, a combiner box with fuses is required. According to the IEC 62548:2016, fuses are mandatory if the maximum return current is higher than the return current of the module.

  How to correctly dimension and calculate fuses you can learn in our fact sheet

• How can I ensure a long service life for a PV combiner box?

  To ensure the return on investment of a PV system, all products from the modules to the inverters and GAKs should have a lifetime of 20 years. The correct selection and design of all components and the subsequent validation of their interaction will result in a long lifetime of the product.

  Which components influence the lifetime of combiner boxes you will find in our fact sheet

• How to connect a combiner box with an inverter with low input current?

  It is popular to install combiner boxes close to the PV modules to combine strings, which may result in the bundled string having too high currents for the input of the inverter. If the current is distributed evenly to the inputs of the inverter, this prevents too high a current from being fed in.

  How this can be implemented in the installation is explained in our fact sheet

• How to combine PV strings and when is this efficient?

  In residential installations, the PV modules are often installed on the roof and the string inverters are placed in the basement. An IEC 61439-2 approved combiner box offers the possibility to combine strings and thus save installation time, material and space for cables running through the building.

  Examples of installation and which cable cross-sections you need for your strings can be found in our fact sheet

• What are the requirements for load break switches in PV systems?

  PV systems require a DC load-break switch according to IEC 60364-7-712. These switches can be integrated in string inverters, combiner boxes, fireman switches or similar devices. Until 2018, DIN EN-60947-3 considered only DC switches for 24 V or lower power ratings. Until 2018, DIN EN-60947-3 considered only DC switches for 24 V or lower power ratings.

  You can find detailed information on surge protection for PV systems in our fact sheet

• What is there to consider with markers and labels for PV systems?

  Photovoltaic installations are designed for a lifetime of more than 30 years. According to IEC 62548:2016, there is a need for UV-resistant marking in PV installations to ensure the lifetime of markers and stickers.

  You can find detailed information on UV resistance in our fact sheet

• When are automatic fireman switches required?

  An emergency shutdown in the event of a fire is specified by the building insurer or the local fire brigade. In this case, the string lines running in the building must be switched off automatically if a fire brigade operation is required. The technical solution is a fireman switch, which is installed at the entry point of the string cables into the building.

  You can find more detailed information about the PV Next Fireman Switch in our Fact Sheet .