Equipotential bonding is a fundamental safety measure in electrical installations, protecting people from dangerous touch voltages. All conductive parts of a building, such as water pipes, heating pipes, steel structures, and protective conductors of the electrical system, are connected to each other via the main equipotential bonding bar. A distinction is made between main equipotential bonding, realized at the building entrance, and supplementary or local equipotential bonding, which is mandatory in damp rooms such as bathrooms. In photovoltaic systems, equipotential bonding is particularly important to ensure lightning and surge protection. Implementation is governed by DIN VDE 0100.