Residuaalkaitselülitid

Residuaalkaitselülitid, also known as Residual Current Devices (RCDs), 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 circuit, the current flowing out on the live wire should be equal to the current returning on the neutral wire.

If an RCD detects an imbalance, it indicates that some current is leaking out of the circuit, possibly through a person who has come into contact with a live conductor. This leakage current, known as residual current, can be dangerous and cause electrocution. When the RCD detects this imbalance, it rapidly trips and disconnects the power supply to the affected circuit, preventing serious injury.

RCDs are not a substitute for earthing, but rather an additional layer of protection. They are particularly effective in preventing shocks from faults where the fault current might be too low to trip a standard overcurrent protection device like a fuse or miniature circuit breaker (MCB). They are commonly installed in homes and other buildings, especially in areas where water is present, such as kitchens and bathrooms, as water increases the risk of electric shock.

There are different types of RCDs, including Type AC, Type A, and Type F, which vary in their sensitivity to different types of residual currents. The selection of the appropriate type depends on the specific electrical installation and the potential electrical hazards present. Regular testing of RCDs is crucial to ensure they are functioning correctly and providing the intended safety.