jordfejlsafbrydere

Jordfejlsafbrydere, also known as RCDs (Residual Current Devices), are safety devices designed to protect against electric shock. Their primary function is to detect and interrupt electrical current that flows along an unintended path, such as through a person. This happens when there is a fault in the electrical system or an appliance, causing current to leak to the ground.

A jordfejlsafbryder works by monitoring the balance of current flowing in both the live (phase) and neutral conductors of an electrical circuit. In a normal, healthy circuit, the current returning through the neutral wire is exactly equal to the current leaving through the live wire. However, if a fault occurs and current leaks to ground, perhaps through a person touching a faulty appliance, the current returning through the neutral wire will be less than the current leaving through the live wire.

The jordfejlsafbryder detects this imbalance. If the difference in current exceeds a predetermined threshold, typically 30 milliamps (mA) for personal protection, the device rapidly trips and cuts off the power supply to the circuit. This interruption happens within milliseconds, significantly reducing the risk of serious injury or fatality from electric shock.

Jordfejlsafbrydere are a crucial safety feature in modern electrical installations and are often mandatory in many countries. They provide an important layer of protection in addition to circuit breakers and fuses, which are designed to protect against overcurrents and short circuits. While they do not prevent all types of electrical faults, they are highly effective at mitigating the dangers of earth leakage currents.