Mersen’s surge protection solutions for photovoltaic systems

Mersen Helioprotection® Surge-Trap® program offers a flexible platform of solutions for power line and signal line protection for PV

Mersen Helioprotection® Surge-Trap® program offers a flexible platform of solutions for power line and signal line protection for PV. Surge-Trap® is the most comprehensive and flexible solution in the market for power line surge protection in PV. All “one-module-wide” plug-in surge cartridges can indistinctly be used across DIN-rail bases or PCB surge-socket bases, this being true for both Type2 and Type1+2 SPDs. The program is also 1500Vdc ready and offers solutions for specific PV issues on the DC side for multiple MPPT and on the AC side with reinforced voltage ratings. Devices are both IEC and UL. No back-up fuse is required on the DC side.

Surge protection devices are installed on the DC and AC sides of central and string inverters, in combiner boxes and to protect signal lines (measurements and communications). Depending on the atmospheric exposure of the PV plant to lightning, EPC contractors and designers may either spec-in standard Type 2 IEC SPDs or more robust Type 1+2 SPDs

DC side protection at combiner boxes and inverters shall typically have the “Y” DIN-rail configuration in order to provide common and differential mode protection. Regardless of the SPD Type and voltage rating, no additional back-up fuse will be needed thanks to Mersen’s optimized dynamic thermal disconnection system for DC PV currents, with 10kA short-circuit withstand rating.

Recently, with the introduction of high power string inverters, new multipole SPD configurations and products have been added to Mersen’s portfolio. Those inverters use a multiple MPPT technology which require special DC SPDs. The best solution is to have the surge base in the format of a special single-pole socket that can be wave-soldered in any network configuration on the PCB, along with other power electronics components. This avoids wiring costs but must usually be planed for at an early stage of design of the inverter. Mersen offers a new PCB surge-socket that can host any of Mersen’s standard DC and AC plug-in surge cartridges, both Type 2 and Type1+2, any voltage rating.