Fuses

Large selection of fuses for your electrical cabinet

Here on the site you will find our large selection of fuses.

All types of electrical devices and installations need some form of protection.

This protection mainly comes from fuses.

Fuses can be found in almost all larger electronic circuits and are what protects your electrical installations from overcurrent, electric currents, and voltages beyond a certain threshold.

Overcurrent is what happens when too much current flows through a wire or your conductor.

Overcurrent can lead to overheating or stress on your circuit, or in the worst case, a short circuit of your device or fire.

Your fuses come in here and receive the overcurrent; in other words, they lead the current towards them, so instead of your electrical circuit being affected, it is the fuses that take the overcurrent.

When a greater than expected amount of current is thus led through the fuses, they will blow and shut off the electrical installation, minimizing the risk of overheating and short circuits.

5 things to consider before buying fuses

Fuses come in many shapes, from small glass tubes to large electronic equipment, but the cartridge fuses are the most common and often the ones you find in almost all electrical cabinets in private homes in Denmark.

The most common variant of these fuses is the cartridge fuse with its white cylindrical ceramic cap and metal ends, which serve as connection points.

At one end, the wire is secured with a spring that ensures it pulls the melted ends of the wire apart, which is what interrupts the current.

The other end of the spring leads out to a small end piece, which you often can see in the middle of one of the two metal ends.

If the fuse burns out, fortunately, there is nothing that keeps that end of the spring firmly in the ceramic cap itself, and thus the end piece falls off.

You can easily find the blown fuse as you just need to look for the end piece that has fallen out of the cap and now lies loose.

Many of the electrical appliances you can find at home and in the office have their own cartridge fuses.

These appliance fuses are often shaped like a glass tube, with end caps very similar to the fuses you find in the electrical cabinet.

This is necessary because although your entire home's electrical installation is protected by fuses, an electrical appliance can still burn out at current levels far below the available current in the fuse group.

This also means that it takes a while before the protection from the electrical cabinet fuses takes effect, and that is why the electrical appliances you have at home have their own fuses.

#1 - Fuses vs. breakers

Fuses and breakers can remind each other quite a bit as they serve very similar purposes; both cut off the current in case of overcurrent or short circuits.

Therefore, it is important that you consider what you really want in safety measures; often, fuses are the most common you can encounter in private homes, as they are mandated by law, and it is typically not difficult to replace blown fuses.

Unlike breakers, fuses must be replaced after having served their purpose, as they are one-time products; once they have burned out due to overcurrent or overload, short circuit or similar, you cannot use them anymore.

In contrast, breakers work much like a socket, and you can easily reset them when you have had to cut off the current.

However, fuses are often cheaper and can very easily be replaced, as long as you have a compatible model.

#2 - How to choose the Amperage of your fuse

It can be difficult to choose the right fuse if you don’t know what to look for, and often, you can get far by choosing something similar to what you already have in the electrical cabinet.

To choose a fuse with the correct Amperage, it is important that you first investigate the normal amount of current flowing through your circuit without it being loaded, of course.

Once you have calculated the correct amount, you need to multiply it by 135%, and round up to the closest value.

10 Amperes x 135% = 13.5 Amperes.

For example, if the normal amount of current is estimated to be 10 Amperes, the closest value will often be 15A.

#3 - How to choose the Voltage of your fuse

It is to some extent easier to calculate how to choose the correct amount of Voltage in your fuse, compared to Amperage.

There is a rule of thumb you can lean on, which is that the Voltage of your fuse should always be higher than the Voltage of the circuit it protects.

For example, if the circuit operates at 24 Volts, the fuse's Voltage should be higher than 24.

Yes, you can even choose one with as much as 250 Volts as long as it is higher than the circuit's Voltage.

#4 - Direct current or alternating current

Almost all circuits can be classified into two different forms, namely direct current (DC) and alternating current (AC).

Alternating current is what you will most often find in private homes supplied by electrical works, and is generated by machines, such as generators.

Direct current, on the other hand, is mainly used in electronics and vehicles, and is often generated through chemical reactions, such as batteries and solar cells.

In alternating current, the electrons move back and forth, helping the fuse to open and close without problems, whereas direct current does not oscillate, and thus the fuse must find other methods to cope.

Because of these differences, you can find fuses that are specifically designed for devices running on direct current, such as vehicles; you can use fuses for alternating current in direct current devices, but the Voltage may decrease in those cases.

#5 - The temperature around your fuse

Normally, fuses are most often tested at room temperatures, which typically hover around 25°C, but this is not always the case when fuses come out in private homes and workplaces.

Fuses are sensitive to heat, as they are designed to absorb heat in connection with overcurrent to melt the fuse element inside.

Therefore, the more heat, the faster the fuse melts; the less heat, the longer it takes for the fuse element to melt.

If you already know that your fuse will be in hotter temperatures than 25°C, you should choose a fuse with higher Amperage, as you may risk having to compensate for the higher temperature.

This is to avoid your fuse blowing unnecessarily.

You should also take this into consideration if the fuse will be in lower temperatures; here you should lower the fuse's Amperage, otherwise, you risk it not blowing.

A good rule of thumb is that for every 20°C higher or lower, you should increase or decrease the Amperage by 5-15%.

Therefore, if the fuse will work in more extreme temperatures, as seen in the example above, you should adjust the Amperage value so that your fuse still operates effectively.