Residual Current Circuit Breaker
The Residual Current Device (RCD), also known as RCCB, is one of the most important electrical safety devices. It plays a crucial role in protecting human life and preventing fires caused by electrical leakage.
This smart device quickly detects leakage currents in the circuit and, in the event of any electric shock hazard, disconnects the circuit in less than one second to prevent damage to humans and electrical appliances.
In simple terms, if a leakage occurs in the circuit (for example, when a human body accidentally touches the live wire), this device immediately cuts off the power by detecting the current difference between phase and neutral.
How an RCCB / RCBO Works
In a healthy circuit, the current in the live (phase) and neutral wires is equal. If a leakage occurs, for example, when a human body touches the live wire, current flows through an unexpected path to the ground, disturbing the balance of the circuit and creating a risk of electric shock and equipment damage.
In such cases, the RCD comes into action. This smart device quickly detects the difference between phase and neutral currents, and as soon as the leakage exceeds the safe limit (usually 30 mA for human protection), it disconnects the circuit in less than 0.03 seconds.
This prevents electric shocks and fires caused by leakage currents, significantly enhancing building electrical safety.
⚡ RCCB / RCBO Key Functions:
Detects current differences between phase and neutral
Rapid disconnection in less than 30 milliseconds
Prevents electric shock and protects electrical devices
📈 Installing a standard RCD is one of the simplest and most effective ways to improve electrical safety when designing or upgrading a building’s electrical system.
Types of Residual Current Devices (RCD / RCCB / RCBO)
RCDs are produced in different models to provide optimal protection according to the type of usage and circuit conditions. Here are the main types and their features:
🔹 Type AC
The simplest type, it only responds to alternating current (AC) leakage.
👉 Suitable for basic household circuits without complex electronic devices.
🔹 Type A
Sensitive to both AC leakage and pulsating DC leakage.
👉 Ideal for modern home appliances, washing machines, air conditioners, TVs, and devices with switching power supplies.
🔹 Type B
A professional model capable of detecting pure DC leakage.
👉 Commonly used in industrial applications, solar systems, drives, and electric vehicle (EV) chargers.
🔹 RCBO
RCBO combines a residual current device with a miniature circuit breaker (MCB).
It not only detects leakage currents but also protects against short circuits and overloads.
👉 Perfect choice for maximum safety in critical building circuits.
🔍 When purchasing, consider the current type, circuit application, and power rating to ensure the best performance and highest safety level.
⚡ Applications of Residual Current Devices (RCD / RCCB / RCBO)
This device is a vital component in any standard electrical system, designed to enhance safety and prevent electric shocks. It is used in various environments and equipment, including:
🏠 1. Electrical panels in homes, offices, and workshops
In residential, commercial, and industrial buildings, this device plays a key role in protecting people and electrical equipment from leakage currents. Installing it in the panel ensures that even minor electrical faults are detected quickly, and the circuit is immediately disconnected.
⚙️ 2. Industrial equipment and machinery
In industrial environments where machines typically have metal bodies and high current consumption, the risk of leakage is higher. This device quickly detects leaks and prevents damage to operators and expensive equipment.
🚿 3. Wet areas such as bathrooms and kitchens
Wet environments pose the highest risk of electric shock. Using this device in such spaces ensures that even sudden contact with electricity will be interrupted within milliseconds, preventing accidents.
Installing a standard RCD is a simple and effective way to improve electrical safety and protect human life. If you are updating or designing a building’s electrical system, be sure to include this device in your plan.
Important Usage Notes:
The rated current of the device (e.g., 25A, 40A, 63A) should match the circuit load.
For human protection, a leakage of 30mA is usually selected.
Press the TEST button every few months to ensure proper functionality.
⚡ A Modern Future, Dena Style
In a world where safety and innovation drive progress, Dena Electric leverages years of experience and outstanding quality to take a major step toward a secure and modern future.
Dena Electric RCCB combines advanced technology, modern engineering knowledge, and international standards. It not only protects lives from electric shock but also represents trust, durability, and Iranian authenticity.
By choosing Dena Electric’s RCCB, you’re not just purchasing an electrical device; you are bringing safety, peace of mind, and a modern Dena-style future to your home and workplace.
🔧 For any issues or malfunctions with the device, visit Dena Service, the official Dena Electric after-sales service center. Our expert team is always ready to provide fast, reliable, and professional support.