How does a basic circuit breaker work?

The diagram on the right shows the set of a basic circuit breaker. It is pretty self explanatory, but this article will go through the steps involved when a circuit breaker cuts off the power to prevent damage or injury following a current surge.

First of all, on the diagram we see that the electricity comes from the right hand side, through a live wire. This wire is the wrapped around a magnet, making it into an electromagnet. The wire then continues along the circuit, along a pivot fixed in place by a spring, then there are two contacts at the top left of the diagram. When all is fine and the current is not to strong, the electricity passes along the contacts and then continues to its destination.

However, if there is a surge in the current, the current through the live wire and around the magnet will become so high that the electromagnet manages to pull the right hand contact away from the other and clicks the pivot into the second position (it moves clockwise). This is why you hear a clicking noise. The spring makes sure that the pivot doesn't move back again. When you reset a circuit breaker by flicking a switch, you are manually pushing the pivot back to its original position, allowing electricity to flow through the contacts again.

Thank you for reading, I know that this explanation is rather basic but hopefully it covers all the understanding you need of how a circuit breaker works, feel free to leave a comment below or any suggestions. If you enjoyed this article or found it helpful please like, share or rate.

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Comments 4 comments

Tamarii2 profile image

Tamarii2 5 years ago from NEW YORK

Interesting hub.Thanks for following .Enjoy your journey.


layla 3 years ago

when would it be used?


john.jackson profile image

john.jackson 3 years ago from London, England Author

In most houses and commercial buildings to avoid an electric shock or damage to electrical devices if there is a power surge, which would most likely be due to a faulty device. Circuit breakers are an alternative to using fuses (they work in the same basic way - they break the circuit). Circuit breakers, however, can be turned back on again and again, whereas fuses are single use.


Pauline 3 years ago

Mine tripped like crazy but I got three cutler hammer circuit breakers from all electric needs inc with free ground shipping. Then when I went to replace them I found another guide on the net that pointed me in the right dir. The thing is I never understood how it worked but this article was top notch. I know exactly how a circuit breaker works now, so the next time I go to buy a new or used one I'll be ready.

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