jarðleiðslu

Jarðleiðslu, literally “earth conduction,” is a term used primarily in electrical engineering and safety to describe the unintended flow of current through the earth or a grounding system. The phenomenon occurs when there is a fault in an electrical circuit, such as a short to the metal chassis of equipment or a damaged insulation, causing current to seek a return path to the ground. Ground fault current is a critical parameter in the design of protective devices because it can lead to hazardous situations, including electrical shock and equipment damage.

Grounding systems are intentionally designed to provide a low‑impedance route for fault currents, allowing protective relay devices or circuit breakers to sense a deviation from normal operating conditions and disconnect the faulted circuit swiftly. The measurement of earth fault current is carried out with instruments such as earth fault loop impedance testers and ground fault detection relays, which continuously monitor for anomalies.

In many countries, regulations and standards (for example IEC 60364 and UL 94 series) mandate specific grounding practices, limit the permissible level of earth fault current, and require the use of residual‑current devices to enhance safety. Effective grounding reduces the risk of electric shock and protects sensitive electronic equipment from transient over‑voltages.

The term is also used in civil engineering to refer to the conductivity of the ground itself, playing a role in the design of buried electrical cables and communication lines. Here, the concept of earth resistance becomes essential to ensure that conductors return to the source efficiently without excessive voltage drop.