1. Basic Structure: An electrical fuse consists of a thin wire or a metal strip made of a material with a low melting point, such as copper or zinc, enclosed within a glass or ceramic housing.
2. Circuit Connection: The fuse is connected in series with the electrical circuit it is protecting. When the circuit is functioning normally, the current flows through the fuse without any issues.
3. Overcurrent Condition: When an electrical circuit experiences an overcurrent condition, such as a short circuit or an overload, the current flowing through the circuit increases significantly.
4. Fuse Melting: As the excessive current passes through the fuse, the thin wire or metal strip inside the fuse heats up due to its resistance. If the current exceeds the fuse's rated capacity, the heat generated causes the fuse element to melt.
5. Circuit Interruption: Once the fuse element melts, it breaks the circuit, effectively stopping the flow of electricity. This interruption prevents the excessive current from reaching the electrical components and appliances connected to the circuit, protecting them from damage.
6. Replacement: After a fuse blows due to an overcurrent condition, it needs to be replaced with a fuse of the same rating or amperage. Using a fuse with a higher rating can be dangerous, as it may not provide adequate protection against overcurrent situations.
It's important to note that fuses are designed to protect against short circuits and overloads but are not meant to protect against ground faults. If a ground fault occurs, where there is an unwanted path for current to flow to ground, a different protective device called a ground fault circuit interrupter (GFCI) is needed.
