Residualstrømsafbryder

Residualstrømsafbryder, commonly known as residual current device (RCD) or residual current breaker (RCB), is a safety device designed to quickly disconnect a circuit whenever it detects an imbalance between live and neutral conductors. This imbalance typically indicates a leakage of current to the ground, which can occur when a person accidentally touches a live part or when an insulation fault happens.

The primary function of a residualstrømsafbryder is to prevent electric shocks and reduce the risk of electrical fires caused by leakage currents. It monitors the flow of current in live and neutral wires, and if the difference exceeds a predefined threshold—often 30 milliamps—the device trips, cutting off power supply within milliseconds.

Residualstrømsafbrydere are commonly installed in residential, commercial, and industrial electrical systems. They are essential components of electrical safety and are often required by electrical codes and standards in many countries. These devices can be standalone units or integrated into consumer units (distribution boards).

Modern residualstrømsafbrydere vary in type, including single-phase and three-phase models, and may feature additional functionalities such as test buttons, indicating lights, and lockout mechanisms to prevent accidental resetting. Regular testing of residualstrømsafbrydere is recommended to ensure proper operation.

While residualstrømsafbrydere are highly effective in preventing electric shocks, they do not provide protection against overcurrent or short circuits; those functions are handled by other protective devices such as circuit breakers. Proper installation and maintenance are crucial for ensuring their reliability and effectiveness in safeguarding electrical systems and users.