RCBOs: The Future of Safe Circuits

 Electricity has been one of the most revolutionary discoveries in human history. Nothing beats the wheel, unfortunately, but what makes a big difference with the use of electricity is the fact that it enhances the function of existing components and methods.

Electrical systems and installations also bring new technologies to places where you wouldn't have expected 100 years ago. But because electrical currents are all around us nowadays safety is as important as an efficient system if not more. Hence why different components have been added to existing installations and systems as well as more advanced ones such as an RCBO.

RCBOs

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What Are They?

RCBO stands for Residual Current Breaker with Over-Current or a device that offers much more than what an RCD or a residual current device does. An RCBO is essentially an all-in-one device that brings together the best safety-related components found in other devices. This is why an RCBO electrical device is attached to every separate circuit so that the fault in one doesn't affect the others. 

Benefits

Although more complex than other types of safety components found in panel boards, RCBOs are made to be more reliable and much safer. They are a lot quicker at disconnecting the circuit and thus the electrical installation as a whole is better protected and so is your home. That's because an RCBO offers a combination of overloading and short-circuit protection from earth leakage currents.

Types of RCBOs

S

A type S RCBO is a sinusoidal RCD that offers a time delay function. This allows you to install a type S RCBO upstream so that you have a more selective solution at hand. Despite its quirks though, a type S RCBO breaker can't be used for added protection since its reaction time is far longer than the 40 ms maximum. Usually, RCBOs have a reaction time between 25ms and 40 ms.

AC

The most common RCBO you'll find used in households is a type AC device. This is a solution that relies on alternating sinusoidal residual current for its operation which is why it can be used on capacitive, inductive and resistive equipment. There's no time delay with a type AC RCBO and it's able to detect any imbalance immediately.

A

With a type A RCBO breaker, you can expect it to work with alternating sinusoidal residual currents up to 6mA. This is why a type A RCBO is also used for residual pulsating DC.

F

When it comes to frequency-controlled appliances like washing machines, dishwashers and air conditioners type F RCBO are often used. Especially equipment with variable-speed drives. 

B

You'll come across type B RCBOs in both single and three-phase equipment. This includes welding equipment, inverters, lifts and even photovoltaic systems.

How to Install an RCBO

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1. It's all about being prepared when it comes to installing an RCBO electrical device. The first step in the preparation process is to isolate the electrical supply from the unit you're going to be adding the RCBO breaker to.

2. Next, you need to remove the front cover of the unit and then prepare the terminal itself. For this, you'll have to unscrew the terminal so its bottom is loose and after that, you should open the clip attached to the bottom.

3. Once the terminal is out, it's time to install the RCBO. For this, you should look for a DIN rail and a bus bar in the panel board which is there to accommodate new components. Put the RCBO circuit breaker in the correct position on the bus bar and then close the clip at the bottom to secure it in place.

4. With that done all that's left to do is to tighten the lower terminal screw and check all of the connections. Ensure that no cables are loose or flimsy as this can cause major issues if left unattended.

Differences Between RCBOs, MCBs and RCDs

There are plenty of differences and similarities between RCBOs, RCDs and MCBs. RCDs or residual current devices are where it all starts as they are made to protect from earth leakage faults. MCBs, on the other hand, aren't capable of this since they are not able to cut off power.

An MCB or miniature circuit breaker is only able to protect from overcurrent and short-circuiting. MCBs are used in lighting circuits and air conditioners but not in devices that come in contact with water. An RCBO circuit breaker, as you already know, can do both which is why it's the preferred device by many electricians. They are the ultimate circuit breakers no matter the application.

Final Thoughts

The world of electrical safety equipment and devices can be a complex one, especially for someone without much expertise. But if you don't know which device to go for it's best that you get an RCBO since it offers the best level of protection and it's as advanced as circuit breakers get.