| How to Reset a Circuit Breaker | Electricalworld.com

Quick Tip: How To Reset A Circuit Breaker

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21st November 2016

While we typically recommend leaving your breaker box for an experienced user, there may be several scenarios in which you might not have much choice, including a tripped breaker.

If power in your house has suddenly cut out in one area or one isolated circuit, a tripped switch in your breaker is the likeliest suspect.

This inconvenience may be warning that your circuits or zones may be overloaded, and you should think about reducing the load on the circuit to lower the risk of electrical fire.

Understanding your fuseboard

Its best to understand what type of device has just tripped first to help you understand the underlying problem.

There are various types of breakers installed in fuseboards, but the main types are MCBs ,RCDs, and RCBOs . Each of these breakers have many variants but for the sake of convenience we’ll just discuss the basics now:


2246An MCB (Miniature Circuit Breaker) is a device which acts like a resettable fuse. It will cut out when overloaded or short circuited.


2242An RCD is a device which is designed to protect property and prevent loss of life from a shock. It acts like a set of scales reading the live and neutral currents in a circuit, and stays on when the load is balanced. But a difference in load measured across both the Live and Neutral currents will cause the RCD to trip, as an imbalance indicates a safety risk.

RCDs are rated based on their tolerance to imbalanced loads, any more than this and the device will trip out.


2241An RCBO Is essentially an MCB and RCD in one device, however it does not typically get used across an entire board to substitute MCBs as an RCD is not always necessary on some of the other circuits.

Understanding why a circuit can trip out and when you can reset it yourself

Too many demanding appliances on one circuit all at once or a faulty plugged-in appliance are the main causes for a tripped breaker, and removing the faulty item or amount of loading on the circuit is the first & most obvious way to correct the problem. After you have done this you can try and reset the breaker.

If the breaker does not reset for you after you have removed the appliances from the circuit you will need to contact a qualified electrician.

If your circuit cuts out and you haven’t done anything different and you have removed all known appliances and still can’t get your MCB/RCD to reset there is maybe an underlying issue, in which case you will need a competent electrician to get involved.

How to Put the MCB/RCD/RCBO Back On

Once you’ve corrected the problem, open your consumer unit’s front door to get a view of the switches, typically one (the one we want) will be out of line with the others, which should be in the ON position. Simply move the OFF switch to the ON position to correct the problem.



If the breaker trips again or frequently, contact a professional approved electrician to diagnose and correct the problem, as while simple, this procedure needs to be understood and only done according to the foregone instructions. Improper resetting of devices could result in an electrical fire or electrocution.

Tip: We do not recommend the use of MCB locks to prevent ‘nuisance tripping’, as tripping indicates a larger electrical problem in your home and should not be ignored. MCB locks are designed for short term use while carrying out electrical repair.


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