Why is it hazardous to replace a fuse wire with a copper wire?

We Kiwis are a nation that loves DIY. We like spending our weekends renovating, gardening, planting, and developing. This DIY spirit can sometimes lead to difficulties. Some jobs shouldn’t be considered DIY. Our home electrics should be left to the professionals.   You may ask “Why is it hazardous to replace a fuse wire with a copper wire?” It is still wire!

You must be able to use electricity correctly. This could cause fire and in the worst case scenario, death. Simple mistakes such as replacing fuse wires with standard copper wires can result in a disaster. Lake Road Electrical visited a client’s house recently and found they were in danger of an electric fire. This was all thanks to a small piece of copper wire. Here’s what actually happened.

It’s not as simple as a bit of wire, it can result in an electrical fire.

But first let’s begin by looking at the purpose of a fuse.

A fuse can be used to remove power from a system that is not working properly. Circuit breakers can be used to replace fuses but they have substantially different characteristics.

A fuse can be described as a piece of wire made from a material with low melting points. Copper wire is not a good choice for a fuse because of its high melting point (approx 1094 degrees C). Copper wire is resistant to heat and will not melt when it is exposed to high-voltage currents.

A 5A means a fuse which can carry 5 amperes of current. If the capacity of a fuse is 5A it will NOT withstand currents greater than 5A. The fuse wire will then melt, breaking the circuit.

Is it possible for a fuse to be replaced by another piece of wire?

You can never replace a fuse using a piece of metal wire. So no, you cannot use copper wire to replace a fuse. Because of its higher melting point, and low resistance, current can flow though copper wire without melting it.

It is never recommended that you bypass any fuse in this way, especially when dealing with a blown one. By using a wire as a bypass to a fuse, you can set off fire or even cause death by electrocution. Don’t take any chances!

A Nightmare Story…

I was called upon to investigate a complaint by the owner about a loud popping sound coming out of the kitchen wall. The owner would hear the noise around 10-15 minutes following turning on the stove. After hearing the sound, the cable was checked for any issues. One problem was that rodents had been chewing it. The most concerning though, was the fuse for the stove.  Someone had taken out the fuse and changed it to standard copper wire. This could be because the rodents chewed on the wire and it blew several times. This basic DIY job could have cost the family their entire home or someone’s life.

The cable was susceptible to catch fire.  However, the owner was very fortunate to have the fire extinguish itself in the wall and not continue to burn.

What caused this problem?

What are your options to stop this type of fire from happening at your location? The fire started when the fuse wire was replaced with copper wire.  RCD’s would have been a much better choice or replace with proper fuse wire.

Understanding the risks requires that we take a step back to see what a fuse does. A fuse is a safety tool that protects appliances and wiring. It can also prevent the possibility of electrical fires. A fuse is simply a section of wire designed to deliver a minimal amount of current. If the wire becomes too hot or it experiences excessive flow, it can melt. When this happens, the circuit is cut and the current is stopped.

This protects you and prevents fires. This melting does not happen if the fuse wire is made of copper. Copper has a melting point higher than the fuse wire tin. Copper wire can heat up at high current but not melt.

Instead, it causes an instant short circuit that can damage your appliance and ignite a fire.

What should You Do?

While it can be frustrating to have a fuse blow, keep in mind that it is happening for your security. It is best to have an electrician perform any electrical work within your house.

If you’re replacing the fuse yourself, be sure to use the right rated fuse wire and not copper wire. Although it is very rare that the fuse wire found in stoves has been replaced with copper, we still find copper wire in power systems that continue to blow.

You may experience an increased level of electrical current in your house for a variety of reasons. The fuses will protect you from danger by protecting you. Do not fall for the temptation to use copper wire with a fuse that has already blown many times.  Better yet, get RCD’s installed in your old switchboard.

Here at Lake Road Electrical we will help you to determine the source of your problem. The fuse wire is there for your safety. If the fuse wire was replaced with copper wire, the circuit cannot stop in the event of an emergency and there is the possibility of a large fire.

Contact a Master Electrician. Our team of Master Electricians at Lake Road Electrical can assist you with all your electrical needs. Contact us now.