fejlstrømsrelæs

Fejlstrømsrelæer, often referred to as RCDs (Residual Current Devices) or GFCIs (Ground Fault Circuit Interrupters) in English-speaking countries, are safety devices designed to protect against electric shock. They work by monitoring the balance of electrical current flowing through a circuit. In a normal, functioning circuit, the current flowing out on the live wire should be exactly equal to the current returning on the neutral wire.

If an imbalance occurs, it indicates that some current is leaking out of the circuit, potentially through a person or an faulty appliance. This leakage current is known as fault current. A fejlstrømsrelæ detects this imbalance, even if it's very small, and rapidly interrupts the power supply to the circuit. This quick disconnection minimizes the duration and severity of any electric shock, preventing serious injury or even fatality.

Fejlstrømsrelæer are crucial safety components in modern electrical installations, particularly in areas where the risk of electric shock is higher, such as kitchens, bathrooms, and outdoor locations. They can be installed as standalone devices or integrated into circuit breakers. The sensitivity of a fejlstrømsrelæ is measured in milliamperes (mA), with common tripping currents being 30mA for personal protection and higher currents for equipment protection. Regular testing is recommended to ensure their continued functionality.