Why is the Residual Current Device (RCD) important?

🔌 What is an RCD?

An RCD (Residual Current Device) is a safety device that continuously monitors the current flowing through the phase and neutral conductors in an electrical network. Under normal operation, these currents are equal. However, if a fault occurs, for example, a person comes into contact with a faulty appliance, part of the current will flow through an alternative path, such as the ground. This difference is called a fault current. The RCD detects this discrepancy, and if it exceeds a preset value (usually 30 mA), it immediately cuts off the power supply, thereby preventing electric shock or fire.

⚙️ How does it work?

The operation of an RCD is based on the principle of current balance. The device consists of an iron core, a permanent magnet relay, switching mechanism, and a test circuit. If the current balance in the circuit is disturbed, meaning the difference between the currents flowing through the phase and neutral conductors is not zero, the iron core detects this, and the relay activates, interrupting the power supply.

🛡️ Why is it important?

• Life protection: The primary purpose of an RCD is to protect human life. It can interrupt the current even with a fault current smaller than 30 mA, which is sufficient to prevent electric shock.

• Fire protection: The RCD can detect earth fault currents that can cause electrical fires, thus preventing such accidents.

• Equipment protection: The RCD protects electrical equipment from faulty power supply, thereby increasing their lifespan.

🏠 Where is it used?

RCDs are widely used:

• In homes: Especially important in bathrooms, kitchens, and other wet areas where the risk of electric shock is higher.

• In industrial facilities: In industrial environments where high-power machinery operates, RCDs play a key role in protecting workers.

• In public buildings: In schools, hospitals, and other public institutions, RCDs ensure the safety of visitors and staff.

🧰 Installation and maintenance

The installation of an RCD must always be carried out by a qualified electrician to ensure proper operation and safety. In addition, it is recommended to check the device's operation regularly, at least once every 6 months, to ensure that it functions correctly when needed.