Take a look at types of electrical circuit protectors
Q: My children are getting old enough to use small electrical appliances. Can you tell me about the types of fuses and circuit breakers? — Jimmy
A: People often think of protection from being shocked, and some devices do this, but house fires are also a serious problem. House fires caused by electrical problems are particularly bad because they often start inside a wall. Especially at night, a fire can spread far before it is even detected.
The most common protective electrical items in most homes are circuit breakers and fuses in the main panel that provides electricity to the entire house. These are designed to shut off the electric current when it exceeds a predetermined level. This is usually either 15 or 20 amperes.
To help understand this, think of an analogy with water flow. An ampere is the actual amount of electricity flowing through a wire, just as gallons per minute refers to the actual amount of gallons of water flowing through a pipe. A bigger water pipe can handle more water, and a bigger electrical wire can handle more amperes. Electrical voltage is the force pushing the amperes through the wire just as water pressure is the force pushing water through a pipe. If you increase the water pressure, more water flows through a pipe. If you increase the voltage, more amperes of electricity flow through a wire.
Certain sizes of electric wires are required by electrical codes to handle certain amounts of amperes. If you plug in too many appliances, the total amperes can be too great for the wire. When this happens, the wire can get very hot and start a fire or short out through the insulation. Both circuit breakers and fuses stop electric current if it gets too high for the wiring. Circuit breakers are most convenient. Once you unplug the excessive appliances, flip the breaker switch to turn the electricity on again.
When a fuse blows, you have to replace it. Even though they are less convenient and seldom installed in new homes, fuses still provide the most reliable and precise protection. This is why many expensive sensitive electronic devices use fuses instead of circuit breakers.
The newest circuit breakers are called arc-fault circuit interrupters, or AFCI. Even though the electric current does not get too high, arcing has a particular signature, and an AFCI shuts off the electricity.
A ground-fault circuit interrupter, or GFCI, is similar to a circuit breaker in that it can be reset, but it is designed to protect against electric shock.
If the insulation on a wire breaks or gets shorted to the ground, the electric current skyrockets and the circuit breaker or fuse shuts it off. A GFCI will detect a slight short circuit or ground fault and shut off the electricity.