How To Test A Fuse? 2023 Complete Guide

A fuse is an essential piece of electrical equipment that safeguards your home and appliances from serious damage. It’s a safety device that breaks an electrical circuit when the current flowing through it exceeds a safe limit.

Fuses are small in size but play a big role in protecting circuits from overload and short-circuit. They are readily available at any hardware store or online vendor at affordable prices. You can also buy them in bulk for less money, depending on how many you need for your repairs.

In case you need to know how to test a fuse or want to buy one, this article has everything you need to know about these handy devices. Here you’ll learn about the different types of fuses, how they work, and how to test a fuse before replacing it.

Table of Contents

Types of Fuses

Before we get into the testing aspect of the fuse, it is important to know that not all fuses are the same.

There are two main types of fuses: blade fuses and cartridge fuses. Blade fuses are the most common type and can be found in most cars. They get their name from the fact that they have a flat, rectangular shape with two exposed metal blades on each end.

Cartridge fuses, on the other hand, have a cylindrical shape and come in different sizes. They are often used in larger electrical systems, such as those found in homes and businesses.

How Do Fuses Work?

All fuses work by interrupting the flow of electricity when it exceeds a certain level. This is done by using a piece of metal that melts when too much current flows through it.

The metal is usually made of lead or tin, which has a low melting point. Once the metal melts, it breaks the circuit and prevents further damage.

Does a fuse get damaged?

When a fuse blows, it means that the current flowing through it has exceeded the safe limit. The element inside the fuse melts, which breaks the circuit and prevents further damage.

Once a fuse blows, it cannot be reused and must be replaced with a new one.

So, the answer is yes. Fuses get damaged.

Testing a fuse using a multimeter

There are various ways of testing a fuse. One of the methods is by using a multimeter. I hope that you understand the basics of a multimeter, whether it is digital or analog.

Now here are the steps to follow when using a multimeter to test the fuse:

Step 1: Set the multimeter to the ohmmeter setting.

Step 2: Connect the leads of the multimeter to the two ends of the fuse.

Step 3: If the fuse is good, the multimeter will show a continuous beep or a reading of zero.

Step 4: If the fuse is blown, the multimeter will show an open circuit or a very high resistance.

As simple as that!

The video below illustrates how to follow the above procedures:

How do you tell if a fuse is blown without a multimeter?

You don’t want to use a multimeter, or you don’t even have it yet you want to do the testing? No problem. All you need is a basic understanding of electricity and the elements.

The most common way to test a fuse is by using a simple circuit. This circuit has two wires, one goes to the fuse and the other goes to ground. If the fuse blows, it will interrupt the flow of electricity between these two wires. This is how you tell if a fuse is blown without a multimeter:

1) Disconnect the power from the fuse.

2) Touch one end of an electric wire to one side of the blown fuse and touch the other end of the wire to the other side of the blown fuse. If there’s an electric current flowing between these two points, then the fuse is good. If there’s no current, then it’s blown and needs to be replaced.

The simple circuit can also include a bulb and a light switch. If the light switch is off, and you touch the electric wire to the side of the blown fuse that’s connected to the light bulb, there should be a current flowing through the light bulb. If there’s no current, then the fuse is blown.

How do you check amp fuses?

Amp fuses are usually checked the same way as standard fuses. You can test them using a multimeter or any other generic method that we have mentioned above. Some things to remember when testing amp fuses:

-If the fuse looks normal and there’s no sound or light coming from the fuse when it’s blown, then it’s probably good.

-If the fuse doesn’t look normal (for example, if it’s melted), then it needs to be replaced.

Testing the fuses by swapping

Well, another ideal method that you can use to test your fuse without having to use a multimeter. Simply swap them.

Swapping entails disconnecting the suspect fuse from the circuit and replacing it with another, either new or that is in perfect working condition.

Does the good fuse work perfectly? If yes, now get back suspect fuse back to the circuit. If the circuit does not work perfectly, then the problem could be with the fuse.

If the circuit still does not work even with the new ‘perfect’ fuse then the problem could be with the circuit and not the suspect fuse. Check other components of the circuit.

However, this method of testing also has some risks. And the biggest one is if the circuit is suspect yet you go ahead to put a goo fuse in it. You already can tell what will happen in this case. Your new fuse may end up blowing up.

Doing the visual inspection

Do you want an easy way out? Simply do the visual inspection.

The visual inspection entails looking for any abnormalities or damage on the fuse. This includes checking for burns, cuts, and broken wires. If there are any abnormalities, then it is most likely that the fuse is not in good condition and needs to be replaced.

A magnifying glass can make the inspection job easier. Simply zoom in to spot any defects.

How do you use a fuse tester?

To use a fuse tester, you will need to attach the appropriate cable to the tester. You will also need to set the fuse tester to the appropriate receptacle.

Once you have attached the cable and set the fuse tester, you will press the test button. The fuse tester will then measure the current flowing through the fuse.

Fuse testers provide an easier alternative for testing fuses than trying to open the fuse panel and checking each fuse.

A tester has a light that will indicate when the fuse is blown.

Reasons for testing a fuse

Why should I test a fuse? You may ask.

There are various reasons for testing fuses.

One reason is to determine if the fuse is good or not. If you have a blown fuse, it is important to know which fuse blew and why it blew. This information can help you troubleshoot the problem and fix it.

Testing fuses can also help you figure out if there is a problem with the power going to a circuit. Testing fuses can also help you identify which circuit is causing the problem.

You also test the fuse to protect your valuable electrionic devices and appliances. A blown fuse can mean that the device will not work and you may have to replace it.

Using a test light

You can also use a test light to check the fuses. This is a good option if you do not have a fuse tester.

To use a test light, you will need to unscrew the end of the light. You will then need to place the end of the light in the socket on the device that you want to check. You will then need to screw the end of the light back on.

If you have a blown fuse, the test light will come on. This means that the fuse is good and needs to be replaced. If the test light does not come on, it means that the fuse is blown and needs to be replaced.

Can anyone test a fuse?

Do you know the basics of electricity and how to handle electronic devices? You can go ahead and test the fuse. Fuses are simple devices and don’t require extensive knowledge to be handled.

However, if you are completely green to electricity and don’t have any experience with electronic devices, you might want to ask a family member or friend to help you out. That way, you can avoid any possible damage to the device.

Where to buy quality fuses

Now that your fuse is damaged, you should think of buying a new one for replacement. The best way to do this is to go ahead and buy quality fuses. You don’t want to waste your money on a faulty fuse that will end up blowing again in no time.

So, make sure that you go for a quality fuse and buy it from a reliable source. ICRFQ is a reliable sourcing agent that can help you get quality fuses in China.