Lightning and surge protection for rooftop PV systems
DEHN protects rooftop PV systems

Lightning and surge protection for rooftop PV systems

Professional planning with an approved concept

The most commonly used PV systems are rooftop systems. They are particularly prone to damage caused by direct and indirect lightning effects due to their exposed location.

Since the PV system is directly connected to the electrical installation of the building, lightning effects can have severe consequences:

  • Damage to the building resulting from direct lightning effects or fire
  • Injury of people inside the building
  • Destruction of or damage to electronic devices caused by direct or indirect lightning effects

Comprehensive protection is therefore necessary and should be planned carefully.

Risk analysis – Prerequisite for professional planning

Professional planning including a risk analysis is indispensable to the safe and reliable operation of PV systems. This risk analysis is performed according to EN 621305-2. It must be adapted to the relevant building and include lightning and surge protection.

Good coordination between the different trades is important

The most important goal of PV installers is to optimise the use of the roof area. Lightning protection installers, however, have to observe the separation distance1 for the lightning protection system. Lack of coordination may cause considerable problems. Therefore, coordination between roofers / lightning protection installers and installers of photovoltaic systems / electricians is essential not only when constructing a new building, but also when retrofitting roof-mounted systems.

 

1What is separation distance? It's the necessary distance between the down conductor and another earthed metal part of the building.

No external lightning protection

Example 1

What is the situation when a photovoltaic system is newly or retrofitted?
Does the new system make lightning protection measures necessary for the entire building?

Einfamilienhaus A - DEHNshield® Basic B - DEHNbox TC180 C - DEHNcube YPV SCI 1000 C - DEHNcube YPV SCI 1000 D - DEHNguard® M E - UNI earthing clamps/saddle clamps

External lightning protection AND sufficient separation distance

Example 2

What does a protection concept for a building with an external lightning protection system and a separation distance that can be maintained look like?

Industriegebäude mit ausreichendem Trennungsabstand A - DEHNventil® B - BLITZDUCTOR® XTU B - BLITZDUCTOR® XTU C - DEHNguard® M YPV D - DEHNguard® M E - UNI earthing clamps/saddle clamps F | Lightning Protection

External lightning protection WITHOUT sufficient separation distance

Example 3

What does a protection concept for a building with external lightning protection where the sufficient separation distance CANNOT be maintained, e.g. metal roofs, look like?

Industriegebäude ohne ausreichenden Trennungsabstand A - DEHNventil® B - BLITZDUCTOR® XTU B - BLITZDUCTOR® XTU C - DEHNcombo YPV SCI D - DEHNshield® Basic FM E | UNI earthing clamps/saddle clamps F | External lightning protection
Contact

Have you got any questions? Contact us.

Technical support ⎟ Photovoltaics

Phone: +49 9181 906 1740

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