Fuses, Circuit Breakers, and Your Fuse Box

Sometimes when the lights go out, the oven stops working, or the radio in your car won't work, it is something easy to fix, such as a fuse. Fuses are short wires that melt and separate in case of higher than expected current. There are several parts to a fuse so that when it blows, the current will shut off on its own to protect it, but the current will not stop flowing through the other circuits.

The wires in the fuse are very thin so they must be held tightly in a sheath so that it will not blow up in case of an arc blast when a fire occurs in the wire, which can happen when the current is very strong. If you are referring to vehicle fuses, the coating is transparent so that you can inspect the fuse yourself to see if it has blown. Wiring in houses usually has fuses that are made of thin glass with a metal strip in the center that is screwed into the fuse box.

Some of the more common types of fuses are cartridge style. Because most are made to be replaced easily to get your circuit back online quickly, the holders are usually constructed for easy and quick removal. These holders are usually not bolted to their conductors and held in place with metal clips that the fuse can be sprung from. The fuse holder is also typically an insulator for the circuit.

A different kind of fuse holder is usually put into panels that control equipment where you will want to have them hidden from view and away from people. This fuse panel is different from the other cartridge holders as that the holder is completely closed in its own box.

The fuse boxes that are the most common are called circuit breakers. These are usually created to automatically turn off the circuit in case of too much current passing through the circuit. Homes and small businesses use smaller ones that have a thin strip of metal that back up to each other so that it will bend when the current passes through. When too much current is generated through the metal strip, the breaker will open, thus turning it off. Larger businesses have larger breakers, which are aided through the use of a magnetic field that is created when the conductors that are carrying the current are tripped by an outside source that oversees the current, called protective relays.

Often fuses are made to blow quickly and have ratings according to as much current as they can handle safely. The best location to put a power system and circuit breaker is in a grounded location so that if the fuse does blow it will continue to be safe when there are people around.