jarðstrengur

A jarðstrengur, often translated as ground wire or earth wire, is a conductor in an electrical system that connects the non-current-carrying metal parts of equipment to the earth. Its primary purpose is safety. By providing a low-resistance path to the ground, the jarðstrengur ensures that if a fault occurs, such as a live wire touching the metal casing of an appliance, the electricity will flow to the earth rather than through a person who might touch the appliance.

This grounding connection helps to prevent electric shock. If a fault occurs and the casing becomes live, a large current will flow through the jarðstrengur to the earth. This large current will typically trip a circuit breaker or blow a fuse, disconnecting the power supply and making the appliance safe. Without a jarðstrengur, the metal casing would remain at a dangerous voltage until the fault is otherwise cleared.

The jarðstrengur is typically colored green or green and yellow in many countries, signifying its role in earthing. It is a crucial component of modern electrical installations and is mandated by electrical codes and regulations in most parts of the world to ensure the safety of users and to protect electrical equipment from damage due to faults or lightning strikes. The effectiveness of the jarðstrengur relies on a good connection to the earth itself, often achieved through an earth rod driven into the ground.