What are breakers?

A circuit breaker is an automatically-operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. Unlike a fuse, which operates once and then has to be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation. Circuit breakers are made in varying sizes, from small devices that protect an individual household appliance up to large switchgear designed to protect high voltage circuits feeding an entire city. Besides the conventional cicuit breaker, there are two additional types of breakers that have added protections, Arc Fault Circuit Interrupter, and Ground Fault Circuit Interrupter, both are described in detail below.

Types of breakers:

Arc Fault Circuit Interrupter (AFCI)

An arc fault circuit interrupter is a circuit breaker designed to prevent fires by detecting non-working electrical arcs and disconnect power before the arc starts a fire. The AFCI should distinguish between a working arc that may occur in the brushes of a vacuum sweeper, light switch, or other household devices and a non-working arc that can occur, for instance, in a lamp cord that has a broken conductor in the cord from overuse. Arc faults in a home are one of the leading causes for household fires, but can be prevented with an Arc Fault Circuit Interrupter.

Ground Fault Circuit Interrupter (GFCI)

A ground fault circuit interrupter is an electrical wiring device that disconnects a circuit whenever it detects that the electric current is not balanced between the phase ("hot") conductor and the neutral conductor. Such an imbalance is sometimes caused by current leakage through the body of a person who is grounded and accidentally touching the energized part of the circuit. A lethal shock can result from these conditions; GFCI's are designed to disconnect quickly enough to mitigate the harm caused by such shocks.

Here is an example of what breakers can prevent.