A fuse is a strip of metal or a wire constructed of copper, zinc, silver or aluminum. Some fuses are made of alloys of these metals. Some fuses use two strips with one designed to melt quickly to prevent a short circuit and another designed to fail in the event of a long-term overload. Fuses are designed to carry a set amount of current and melt rapidly when any excessive current is applied. Fuse wires must be as short as possible to avoid causing unnecessary resistance to the electrical system.
There are several different types of fuses. The most common in the automotive industry is called a cartridge fuse. Cartridge fuses are held in place by spring clips and are easy to replace when necessary. The most common fuse used in homes is a circuit breaker. Circuit breakers are switches that open up to stop current in the event of an overload. They can be closed by the flip of a switch. Circuit breakers are common in homes, businesses and industrial services.