A circuit breaker is an electrical device used in an electrical panel that monitors and controls the amount of amperes (amps) being sent through the electrical wiring. Circuit breakers come in a variety of sizes. For instance, 10, 15 and 20 amp breakers are used for most power and lighting needs in the typical home. Some appliances and specialty items (washers, dryers, freezers, whirlpools, etc.) will require a larger circuit breaker to handle the electrical load required to run that appliance.
If a power surge occurs in the electrical wiring, the breaker will trip. Essentially, a circuit breaker is a safety device. When a circuit breaker is tripped, it may prevent a fire from starting on an overloaded circuit. It can also prevent the destruction of the device that is drawing the electricity.
While a number of older homes and buildings still use fuses to monitor the electrical load, almost every newer home has circuit breakers in the electrical panel. Fuses perform much the same duty as circuit breakers. However, circuit breakers are safer to use than fuses and easier to fix. When the power to an area shuts down, the homeowner can look in the electrical panel and see which breaker has tripped to the "off" position. The breaker can then be flipped to the "on" position and power will resume again.
Common circuit breaker include miniature circuit breaker, residual current circuit breaker(RCCB), residual current circuit breaker with overload protection(RCBO), leakage circuit breaker, moulded case circuit breaker(MCCB) and air circuit breaker(ACB).