That is a great question. Simply put it is a safety device that can stop the flow of electricity in a circuit. It is important to understand the limitations of a circuit breaker in your application to make sure you are protected. It is easy to get into trouble when we misunderstand what the CB actually protects against.
A circuit breaker interrupts power in two main configurations switching and interrupting.
When a circuit breaker is manually opened (power off) or closed (power on) it servers to control the electrical flow to certain appliances. This is helpful when performing maintenance and testing.
The circuit breaker is constantly monitoring the power flowing through it. When the current (amps) exceed the limits the breaker will automatically open (power off) to protect people, equipment and the source from damage. Check out our article on how circuit breakers work to gain a better understanding of the various technologies used to monitor the power.
It is important to remember that circuit breakers focus on controlling the amount of current in the circuit and don’t monitor voltage or power quality. You can also compare a CB to a fuse. The main difference is, when a fuse has too much current, it breaks itself to stop. Where as, a CB is re-settable while normally not getting ruined once it has tripped.
Click to view our spec sheet on circuit breakers.