Safe and reliable electricity is a fundamental requirement for both residential and commercial properties. As the number of electrical devices grows, so does the load on electrical networks — along with the risks of short circuits, current leakage, or electric shock. That's why differential protection devices are becoming essential components in modern electrical installations. One of the most convenient and effective solutions is the RCBO.
What Is an RCBO in Simple Terms?
An RCBO (Residual Current Circuit Breaker with Overcurrent Protection) is a combined device that offers two key protective functions:
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Detects current leakage (like an RCD)
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Trips in case of overload or short circuit (like a circuit breaker)
In simple words, it monitors:
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Leakage current caused by insulation faults or accidental human contact with live parts
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Overload conditions
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Short circuits
An RCBO combines the functionality of an RCD and a circuit breaker in one compact unit. This saves space in the distribution board and simplifies installation.
RCBO vs. RCD: What’s the Difference?
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|
| |||
| Yes | Yes | |||
| Short circuit and overload trip | No | Yes | |||
| Requires external circuit breaker | Yes | No (built-in) | |||
| Purpose |
| Full circuit protection |
How Does an RCBO Work?
An RCBO constantly monitors the current flowing into and out of the electrical circuit. If it detects a difference (e.g., current leaking to earth through damaged insulation or a human body), it immediately disconnects the circuit.
Additionally, like a standard circuit breaker, it trips when the current exceeds safe levels or during a short circuit.
Types of RCBOs
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Electromechanical RCBOs: Work independently of supply voltage. They can detect leakage even without a neutral wire. Considered more reliable.
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Electronic RCBOs: Depend on voltage supply from the circuit. They have a smaller differential transformer and no amplifier, making them more affordable but slightly less robust.
RCBOs as Part of a Comprehensive Protection System
RCBO installation is especially important in:
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Wet zones (bathrooms, kitchens)
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Socket outlet groups
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Children's rooms
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Private homes (to protect appliances from leakage to metal casings)
UEC offers RCBOs in various types and ratings — suitable for residential and professional use.
How to Properly Install an RCBO
Correct RCBO installation is key to ensuring the safety and reliability of your electrical system. Whether in an apartment, private house, or office, follow these steps:
Step 1: Preparation
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Turn off the main power to avoid electric shock.
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Check for voltage absence using a tester or multimeter.
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Read the device manual: It contains the rated specs, wiring method, and diagram.
Step 2: Choose the Right Location
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The RCBO is mounted on a DIN rail in the panel — usually after the main circuit breaker or meter, and before the load (sockets, lighting, etc.).
Step 3: Wiring the Device
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Connect the live wire (L) and neutral (N) from the power supply to the top terminals (input side).
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Connect the load wires (L and N) to the bottom terminals — leading to sockets, lights, etc.
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If available, connect the ground terminal to the grounding system (if required).
Warning: Don’t mix up the neutral wire from the power supply with the neutral wire from the load — this is a common mistake that causes false tripping.
Tips for Beginners
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Follow wire color coding:
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Live – brown or black
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Neutral – blue
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Earth – yellow-green
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Tighten terminal screws securely to prevent overheating or contact burning.
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Avoid wire crossing, especially in complex boards.
Common Wiring Mistakes
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Reversing line and neutral — disrupts device function.
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Combining neutral wires from different circuits — creates leakage current.
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Ignoring total load capacity — an undersized RCBO may trip even under moderate loads.
When to Call a Professional
If you lack experience with electrical installations, it's safer to hire a licensed electrician. Incorrect RCBO installation can lead to device failure, fire hazards, or electric shock.
UEC’s RCBOs come with detailed wiring instructions and certified safety compliance, making them suitable for both beginners and professionals.
Benefits of UEC RCBOs
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High tripping precision
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Reliable protection against overload, short circuit, and leakage
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Compliance with European safety standards
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Easy mounting on standard DIN rails
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Available in 6 A, 10 A, 16 A, 25 A, 40 A versions
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Sensitivity options: 10, 30, 100 mA
Why Choose an RCBO?
An RCBO is the best choice for users who want comprehensive protection in one compact device. It combines the benefits of both an RCD and a circuit breaker, saves panel space, and improves safety.
Before installation, always select the proper specifications and avoid common wiring mistakes.
Looking for certified and high-quality RCBOs? Check out UEC’s catalog — designed for everything from basic residential needs to complex industrial systems.
