Condensation under roof tiles: Underestimated risk for PV cables
Condensation regularly forms on the underside of roof tiles. What is usually accounted for in roof construction becomes a problem for unprotected solar cables. Especially at roof penetrations, moisture can cause long-term damage.
How does condensation form on the roof?
Warm air from inside the building rises and hits the cold underside of the roof tiles, where the moisture condenses. This phenomenon occurs more frequently in the transitional months of autumn and spring. The water droplets collect and can run along cables and penetrations into the roof interior.
Dangers for PV cables
- Corrosion at contact points: Even slight moisture can lead to corrosion on MC4 connectors or terminals.
- Leakage currents: Moisture on the cable surface can cause unwanted leakage currents.
- Insulation damage: Permanently wet cables age faster, and the insulation becomes brittle.
- Mold formation: In areas of leaky penetrations, mold can form on insulation material.
Protective measure: Protected cable penetration
The most important protective measure is a professionally installed roof penetration that provides permanent mechanical protection for the cable. NEXCAPE penetrations made of TPU (Thermoplastic Polyurethane) reliably seal the opening in the roof. The elastic material adapts to the tile surface and prevents condensation from entering along the cables.
Constructional peculiarities
NEXCAPE penetrations are designed so that the cable openings fit snugly without pinching the cables. This prevents capillary effects, where water is drawn into the penetration along the cable surface. Tool-free installation without MC4 removal also ensures that the connector connections are not unnecessarily opened.
The right solution for every system size
From small balcony power plant additions to large roof systems, NEXCAPE offers the right variant: 2 PV to 6 PV, optionally with PE for grounding. The lengths 105 mm, 125 mm, and 150 mm cover all common roof structures. Manufactured by 3D printing in Germany.
Cable protection starts with the penetration: find suitable PV roof penetrations
