Fuses offer a simple solution to protect devices from overcurrent. They are installed in a circuit where they regulate the voltage. If excess current enters the circuit, it won’t be able to travel through the fuse. The fuse will break or melt while subsequently breaking the circuit. As a result, the device or devices on the circuit will be protected from overcurrent.
While there are different types of fuses, they are all designed for a single use. You can’t reuse a fuse after it blows. Blown fuses are those that have been exposed to excess current. Excess current will break or melt the fuse’s element, rendering it unable. Fortunately, there are several ways to spot a blown fuse.
#1) Visual Inspection
Performing a visual inspection will often reveal whether a fuse is blown. Most fuses consist of a wire filament encased in a clear plastic body. If the circuit’s current exceeds that for which the fuse is rated, the wire filament will break or melt.
Because fuses have a clear body, you can look into them to see if they’ve blown. Take the fuse out of the circuit and carefully inspect the wire filament. If you discover that the wire filament is broken or burned, it’s safe to assume the fuse is blown.
#2) Turn on the Device
You can try to turn on the device. All fuses are used in conjunction with one or more devices. After all, they are designed to protect devices from overcurrent.
If you believe a fuse may be blown, turn on one of the devices on the same circuit. A blown fuse will render devices inoperable. You won’t be able to turn on any devices on the same circuit. A blown fuse will break the circuit so that the connected devices are unable to receive power.
#3) Test With a Multimeter
The best way to tell if a fuse is blown is to test it with a multimeter. A multimeter is a tool for measuring voltage, current, resistance and more. You can also use it to tell whether a fuse is blown.
To test a fuse with a multimeter, remove the fuse from the circuit. Next, touch the multimeter’s probes to the two ends of the fuse. With the multimeter set to test for resistance, it will reveal whether the fuse is blown. Using a multimeter is the most accurate way to tell if a fuse is blown.