Jordfeilstrømsreléer

Jordfeilstrømsreléer, often abbreviated as RCDs (Residual Current Devices) or GFCI (Ground Fault Circuit Interrupters) in some regions, are safety devices designed to protect against electric shock and fire hazards caused by earth faults. They work by monitoring the current flowing through the live and neutral conductors of an electrical circuit. In a healthy circuit, the current flowing out on the live wire should be exactly equal to the current returning on the neutral wire.

If an earth fault occurs, such as a person touching a live wire that is also in contact with the earth, some current will bypass the neutral conductor and flow to the earth. This creates an imbalance in the current between the live and neutral wires. A jordfeilstrømsrelé detects this imbalance, which is referred to as the residual current. When the residual current exceeds a predetermined threshold, typically 30 milliamperes for personal protection, the jordfeilstrømsrelé rapidly interrupts the electrical supply, disconnecting the power to the affected circuit.

This rapid disconnection significantly reduces the risk of severe electric shock. Jordfeilstrømsreléer are a crucial component of modern electrical installations and are mandated in many building codes and regulations for safety reasons. They are distinct from circuit breakers, which primarily protect against overcurrents (overloads and short circuits) but do not offer the same level of protection against earth faults. Therefore, both devices often work in conjunction to provide comprehensive electrical safety.