jäännösvirran

Jäännösvirta, known in English as residual current or leakage current, refers to the unintended flow of electric current through a path that is not part of the intended electrical circuit. This typically occurs when insulation breaks down or is damaged, allowing current to escape the intended conductors and flow through alternative paths, such as the earth, water, or a person.

In electrical safety systems, residual current devices (RCDs), also known as ground fault circuit interrupters (GFCIs) in some regions, are designed to detect these small imbalances in current. An RCD monitors the current flowing into a circuit and the current returning from it. If the amount of current flowing out does not equal the amount returning, it indicates that current is leaking somewhere else, potentially through a person touching a faulty appliance. In such a scenario, the RCD quickly interrupts the power supply, preventing electric shock.

The presence of jäännösvirta can be a sign of faulty wiring, damaged equipment, or improper installation. It poses a significant safety hazard, as contact with a path of residual current can lead to severe injury or fatality. Regular inspection and maintenance of electrical systems are crucial to identify and rectify sources of residual current, ensuring the safety of individuals and property. The sensitivity of RCDs can be adjusted to detect very small leakage currents, providing a vital layer of protection against electrical hazards.