Grounding and equipotential bonding

Earthing in PV installations: safety and compliance with standards

When installing a solar panel system safely, it is essential to distinguish between earthing and equipotential bonding. Earthing ensures that fault currents and lightning currents are safely discharged into the ground. Equipotential bonding prevents hazardous voltage differences between electrically conductive parts, such as wire mesh cable trays, mounting rails and metal enclosures.

Solar panels behave like capacitors in relation to the earth. In theory, no current should flow from the positive or negative pole to earth in a pure DC system. However, in practice, the voltage from a transformerless inverter contains an AC component relative to earth. As a result, leakage currents flow from the panels to earth. For this reason, all metallic components of the installation, including wire mesh cable trays, must be interconnected by functional equipotential bonding. This prevents unwanted voltage build-up and reduces electromagnetic interference. Properly executed earthing and equipotential bonding increase safety, minimise the risk of faults and contribute to the system’s longevity. In addition, this ensures compliance with the NEN 1010:2020 regulations, which are mandatory for safe low-voltage installations in the Netherlands.

For Conduct systems such as RoofSupport, PVbox and PVshelter, preassembled equipotential bonding kits are available. These enable a fast, reliable and standards-compliant connection.