Photovoltaic energy generation is one of the fastest-growing green energy sources. Hundreds of MW of rooftop systems and utility-scale PV parks are installed every year. Best system availability and minimised OPEX (operational expenses) define the profitability of any size of system.
PV systems are directly exposed to environmental conditions due to the fact that they are always installed in extraordinary locations. Thus, the probability of being impacted by lightning is high. Unprotected PV systems suffer repeated and significant damage to their components. This results in substantial repair and replacement costs, system downtime and loss of revenue. Automation systems, monitoring components and PV inverters must be protected reliably and in line with current standards. IEC and UL standards define precisely the rules to be applied for implementing state-of-the-art PV installations.
PV systems are at high risk of lightning strikes due to their installation in exposed locations and must therefore be protected against surges in accordance with EN 61643-32. To avoid system failures, high repair costs and loss of sales due to surge damage, powerful PV arresters are the best solution.
PV Protect is the compact solution for optimum protection of the inverter against overvoltages The ready-to-connect boxes are available for different system voltages and can be supplied with various arrester types and MPP trackers. Depending on requirements, connection is made via cable glands or WM4C connectors with convenient and reliable PUSH IN connection technology.
The 5-pole product variant is characterized by its compact, space-saving design and thus enables the connection of two MPP trackers. The complete portfolio includes voltage classes from 600 V to 1,500 V.
The figure on the left shows the general architecture of a PV system. The table below is intended to help you select the correct surge protection products according to the specifications of applicable standards in a PV system.
L1 describes the cable length between the main distribution board and PV inverter (AC side) and L2 describes the line length between PV inverter and PV generator (DC side). With a line length > 10 m, an SPD is required on both sides by the standard.
| Question 1 | Question 2 | Question 3 | Question 4 | Installation locations AC | Installation locations DC | ||
| Outdoor lightning protection system present? | Separation distance observed? | Line length L1 less than 10 m? | Line length L2 less than 10 m? | SPD 1 | SPD 2 | SPD 3 | SPD 4 |
| No | - | No | No | TYP II AC | TYP II AC | TYP II PV | TYP II PV |
| No | - | No | Yes | TYP II AC | TYP II AC | TYP II PV | - |
| No | - | Yes | No | TYP II AC | - | TYP II PV | TYP II PV |
| No | - | Yes | Yes | TYP II AC | - | TYP II PV | - |
| Yes | Yes | No | No | TYP I AC | TYP II AC | TYP II PV | TYP II PV |
| Yes | Yes | No | Yes | TYP I AC | TYP II AC | TYP II PV | - |
| Yes | Yes | Yes | No | TYP I AC | - | TYP II PV | TYP II PV |
| Yes | Yes | Yes | Yes | TYP I AC | - | TYP II PV | - |
| Yes | No | No | No | TYP I AC | TYP I AC | TYP I PV | TYP I PV |
| Yes | No | No | Yes | TYP I AC | TYP I AC | TYP I PV | - |
| Yes | No | Yes | No | TYP I AC | - | TYP I PV | TYP I PV |
| Yes | No | Yes | Yes | TYP I AC | - | TYP I PV | - |
Lightning and surge protection for PV systems always has two areas: Lightning and surge protection is required on direct current (DC) and alternating current (AC) sides in order to protect both areas.
When selecting components, a distinction must be made between systems with and without external lightning protection. If external lightning protection is available, a type I+II arrester should be used. Our selection guide makes it easier for you to choose the right surge protection products in accordance with the specifications of the applicable standards in a photovoltaic system.
The following applies to the AC range:
Since 2018, the integration of surge protection (in accordance with DIN VDE 0100-534) has been mandatory. This applies to all new buildings and to modifications or expansions of existing electrical installations.
The following applies to the DC range:
Please have a look at the standard DIN EN 62305-3 or VDE 0185-305-3 - Supplement 5. It describes that the need for surge protection measures on the AC side of the PV power supply system is determined in accordance with DIN VDE 0100 443. If this results in the need for surge protection measures on the AC side and if protection of the inverter is to be ensured, then surge protection are also required on the DC side.
In order to protect photovoltaic systems, the surge protection unit must be installed on both the direct current (DC) and alternating current (AC) sides. The surge protection unit should be installed as close as possible to the device to be protected.
Depending on the application, there are different installation locations, which you can find in our selection guide .
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