The importance of a fuse in an electrical circuit can not be overemphasized because, without a fuse, electrical appliances or circuits would suffer from getting blown up due to excess electric current.
Devices like mobile phones, TVs, monitors, water heaters, iron, dishwashers, laptops, etc all have fuses. Every device or machine with an electrical circuit has a fuse. Even cars have fuses. The fuse protects components of a device or machine from an electrical surge.
An electric fuse is made up of a thin fuse wire or metal strip placed inside a non-combustible material like glass, plastic, or ceramic tube and then connected to two metal terminals on both ends. The tiny fuse wire is made up of Zinc, Copper, Aluminium, or Silver. Fuses come in different shapes and sizes
There’s a little chance of a fuse going bad without being blown up. Most times, the only reason a fuse can go bad in a circuit is getting blown up due to excess electrical current entering a circuit. Whenever there is an excess flow of current, the thin wire inside the fuse melts, and sometimes, the incombustible material in which the wire is sheathed melts or breaks.
However, in some cases, the thin metal strip in a fuse might not be well connected to either of the metal terminals on both ends which can cause the fuse to go bad. This might be a fault from the manufacturer or probably from poor handling.
When electric current flows through an object, it heats up the object. An example of an object like that would be an electric bulb. In a situation where excess electric current flows through an object, it leads to the object being heated up excessively which can cause the object to melt or get blown up.
In worse cases, it can lead to a fire outbreak. The fuse in a circuit causes a break in the circuit when there is an excess flow of electricity thereby stopping the flow of electricity
In the process of stopping the excess electrical current from entering the circuit, the thin wire in the fuse melts or the fuse gets blown up. So literally, they are like sacrificial objects in a circuit. A fuse getting blown up actually means it served its purpose in the circuit by protecting it from an electrical surge.
How To Tell If A Fuse Is Bad
The first way to check if your fuse is blown is by visually inspecting the fuse. When a fuse is burnt, the thin metal strip inside the melts or you see burnt marks on the fuse. Sometimes the non-combustible material like glass, ceramic, or plastic melts or breaks.
Also, you want to check the metal strip inside to see if it’s connected on both ends of the metal terminal.
Another way to know your fuse has gone bad is to make use of a multimeter. No matter the shape or size of the fuse, you can test them the same way.
Using the Ohm setting, all you just need to do is touch both ends of the fuse with the probes of the multimeter. If the fuse is still good, it will show a reading of zero on the multimeter which means there’s no electrical resistance.
Using the continuity test, touch both ends of the fuse with the probes of a multimeter, and if you get a beeping sound, it shows your fuse is still good and there’s a circuit completion but if you don’t get any sound or reading, it shows there’s no circuit completion which means the fuse is bad.
Also, it’s important to note that to carry out this test with a multimeter, it can’t be done on a metal surface. If done on a metal surface, you’ll get a false reading.