Which, between RCBO vs. RCCB breakers, do you need for your electrical system? To answer the question, we compared the two devices side by side. The information will help you choose the best option for your projects.
What is RCBO?
RCBO stands for residual current circuit breaker with overcurrent protection. It refers to an electrical safety device that provides overcurrent and residual current (earth-fault) protection.
In other words, it combines an MCB and RCD into one unit. The overcurrent protection part uses thermal and magnetic mechanisms to disconnect circuits during overload or short-circuit conditions.
On the other hand, the ground-fault protection uses a toroidal transformer. This mechanism operates according to Kirchhoff’s current law. It detects the current imbalance between the live and neutral wires.
RCBOs are popular fault protection devices today, owing to their ability to function as two breakers in one. You’ll mainly find them installed in most modern electrical systems.
What is RCCB?
RCCB stands for residual current circuit breaker. It refers to a type of circuit breaker that disconnects power upon sensing an earth-leakage/earth-fault current.
Earth leakage occurs when current running through a conductor finds an alternate path to ground. Causes include damaged insulation or a person touching a live conductor.
The RCCB works by monitoring the current flowing in a circuit with a toroidal transformer. In a healthy system, the current in the live and neutral wires is equal and balanced.
A slight change disrupts the balance, triggering the breaker to trip circuits. The mechanism disconnects power instantly, protecting people and electrical equipment in the event of a fault.
Many older electrical systems use the RCCB. The device is usually paired with a miniature circuit breaker (MCB) to meet the protection requirements.
Installing an RCBO in a small electrical panelRCBO vs. RCCB
Now that we understand their construction and working, let’s learn the difference between RCBO and RCCB breakers. We will compare them on these fronts: function, size, construction, tripping characteristics, and cost.
Functional Differences
An RCBO is a two-in-one breaker. In addition to ground-fault sensing, it includes magnetic and thermal systems to detect overloads or short circuits.
It reacts to overcurrent situations, such as overloads and short circuits, while also protecting against ground faults.
An RCCB can only detect and react to an earth fault. As such, it requires pairing with an overcurrent protection device, such as an MCCB.
Construction and Size
An RCBO combines two functions in one single device: overcurrent protection and an earth-fault current detector. This construction makes it larger than a residual current breaker.
The residual-current circuit breaker has only one disconnection mechanism: the ground-fault sensing transformer for earth-leakage currents. It’s, therefore, a smaller size for similar ratings.
That means it takes up less space in the panel. However, since it requires an overcurrent breaker, it requires more installation room than the RCBO.
Tripping Characteristics
The RCBO serves as both an RCCB and an MCB. It comes with varying sensitivities for earth leakage current. The standard limit is typically 30mA, which is ideal for homes, offices, and similar settings.
An RCCB will only trip when it senses an earth leakage current. It’s also available in these options, based on their trip curve characteristics: AC, A, B, and F. Current sensitivities range from 30 mA to 100 mA or higher.
Cost Comparison
An RCBO breaker costs more upfront than a residual current circuit breaker. That’s because it offers two protection methods.
The RCCB is cheaper to buy initially. However, you must use it with an MCB, unlike an RCBO, which serves as both an overcurrent and earth-leakage current protector.
The breaker with earth fault protection, therefore, becomes a more cost-effective option. It saves both space and money, making it a favorite choice for electricians today.
The functional difference between RCBO and RCCB breakers illustratedRCBO or RCCB: Which Is Better?
The answer is that it depends on your situation and preferences. One device offers combined protection and space savings, while the other is a low-cost option but requires a separate overcurrent device. Here is how to choose between the two.
When to Use RCBO
We suggest using an RCBO if you’re protecting a new installation or if you have space constraints. The choice is also excellent for situations that present higher shock risks. They include bathrooms and workshops.
When to Use RCCB
An RCCB is more ideal when retrofitting an older system with an existing MCB for overcurrent faults. You may also choose it if you have sufficient installation space for two devices. You’ll spend less to protect the system.
Selection Tips When Choosing Between RCBO vs. RCCB
Anyone choosing between RCBOs and RCCBs must do so with sufficient knowledge of the function and benefits of each device. That’s because they differ in many ways, from how they work to their cost. Use these tips to make the right choice.
- Newer systems benefit more from a breaker with residual current protection. It saves space by reducing the number of devices required. They are mainly residential and commercial electrical systems.
- An RCBO will have you pay a higher initial cost. However, the protection it offers is comprehensive. You can also install it in a cramped panel without challenges.
- Choose a breaker that meets your local electrical protection requirements. You want the installation to comply with your location’s electrical codes.
- Ensure the device you choose is correctly specified for tripping. Sensitive circuits require specific trip curves, usually A, F, and B.
- If unsure, consult a professional to choose the most suitable breaker for you. Electrical systemsvary, and the best device for your application requires a thorough analysis of your needs.
Conclusion
The differences between RCBO and RCCB circuit breakers define their purposes and suitable uses. A residual current serves two functions (overcurrent and earth fault protection). On the other hand, RCCBs can only protect against earth-leakage faults. Ensure your choice accounts for each function.
