RCCB or Residual Current Circuit Breaker: An Overview

It is not uncommon these days to hear about MCB, RCB or RCCB. Whether you are a homeowner or an industrialist, you must have heard about it. Now, you will learn more about it as this article discusses in detail the mechanism of an RCCB, the different types of RCCBs, and their benefits and limitations as well.

What is an RCCB?

An RCCB (Residual Current Circuit Breaker) is a type of circuit breaker that is used to protect against electrical shocks. It is designed to break the circuit when there is a leakage in the current flowing through the circuit. This difference can be caused by a fault in the circuit or by a person touching a live wire. Upon sensing residual current, the RCCB trips the circuit.  

Various Types of RCCB

The Residual Current Circuit Breaker, or RCCB, can be classified into 3 types based on the source used.

. Based on the number of poles, RCCBs are of two types- 2-pole and 4-pole. While first one works in single-phase connections, and the latter one is for three-phase connections.  

How RCCB Helps?

It is said that human beings can withstand a shock of up to 30 mA. But, when it goes beyond 10 mA due to the uneven flow of current in two wires inside a circuit, the prickling sensation of shock turns into major impacts like muscular contraction, breathing trouble, and so on.

RCCBs are designed to recognise even a minor change in residual current. When it senses the change, it disconnects the circuit and saves you from the major impacts of a shock.

The Benefits of Using an RCCB:

The major benefits of RCCBs are as follows:

• An RCCB protects against earthing faults.
• It also protects against any other sort of leakage of current.
• It breaks the circuits automatically when sensitivity exceeds what is rated.
• With the help of the filtering device inside it, an RCCB protects against voltage fluctuation.
• It makes dual termination for cable and busbar connections possible.

Overall, RCCB aims at protecting individuals from the fatal impacts of electric shock by recognising residual current due to a fault in the circuit.

Are There Any Drawbacks?

While there are multiple benefits, there are certain limitations, too, with RCCBSs. Let’s see what they are.

• RCCBs cannot protect against overheating, which strikes if conductors into terminals are not properly screwed.
• It cannot protect against line-neutral shocks as it has a balanced current in them.
• An RCCB cannot detect a current overload.
• Unwanted tripping may occur if you choose an incorrect or very low sensitivity-rated RCCB. Sometimes, a sudden change in loads and a current flow resulting from it lead to tripping.
• As it is designed to operate on normal supply waveforms, it may not operate if the loads generate non-standard waveforms.

How to Select the Right RCCB for Your Application

Not all RCCBs are suitable for your application. To ensure the desired result, you must choose the right RCCB.

First of all, you should focus on selecting the right ratings.

Usually, for household requirements, 30-100mA is normal. However, 30 mA is quite sensitive and can cause tripping issues without any visible fault. 60mA and 100mA are ideal for your house. They create a balance between no obvious fault and actual fault.

In construction sites, you should use portable devices with high-sensitivity RCCB. 100 mA is the ideal rating for RCCBs used on these sites. It is best to discuss with an expert to learn more about the ideal rating.

Also, you should note another factor. You may get confused between RCCB and RCBO.

RCCB is a circuit breaker device that disconnects the circuit when it senses a current leakage to the earth wire.

RCBO, or Residual Current Breaker with Over-current, includes the functionality of MCB (Miniature Circuit Breaker) and RCCB. When a current leakage appears, it trips the whole circuit.

Above all, you must choose the right place to buy the RCCB, where a wide range of variations is available. Otherwise, you may buy a faulty piece or an RCCB with an incorrect rating.

To Sum Up

An RCCB, with all its benefits, is an important component to be added to electrical circuits. Whether domestic appliances or industrial equipment, residual current circuit breakers can protect them from damage and save you from electrical shocks.

By reading the blog, you should be able to identify the need for an RCCB. Also, you learned how to select the right RCCB and where to find the desired one. Anyways, if you plan to buy it for your home or office, L&T-SuFin offers an array of high-quality RCCBs. Check out the site and opt for your preferred one today!