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Is It Ok to Connect Different Gauge Wires? | What to Know

In this article, I will highlight what you need to know about splicing different gauge wires for your home’s electrical projects.

It is not recommended to connect different gauge wires because they may not work and could damage your home’s wiring system. However, if you are connecting two different wires of the same gauge, e.g., 12/2 to 12/3 gauge, it is okay to connect them, and it won’t cause problems.

Now, I’ll answer a few common questions people have on this topic.

Can I Connect 14 Gauge Wire to 12 Gauge Wire?

You shouldn’t connect a 14-gauge wire to a 12-gauge wire because a 12 AWG one carries more current (load), and this can lead to the wires melting, short-circuiting, or even exploding. 

For example, a 12-gauge wire is much thicker than a 14-gauge wire. If you use too small of a gauge for your project, it will be more difficult to get enough power to the device and could cause an electrical fire.

Connecting wires of a different gauge can be a challenge. The wire you use should be close to or the same gauge as the other wire, or it will not work. You should also know what kind of wire you are using before you connect it to another type.

Can I Mix 10 Gauge Wire With 12 Gauge Wire?

It is not advisable to mix a 10-gauge wire with a 12-gauge wire. However, you can use a 10 AWG in place of a 12 AWG, but you cannot use a 12 AWG wire in place of a 10AWG. The two wires have different thicknesses, and the voltage will not be equal. 

The problem with mixing gauge wires is that the higher-gauge wire will have a larger surface area and produce more heat. As a result, the lower-gauge wire can melt because it doesn’t have enough capacity to power the load.

Another factor to remember is the materials you want to connect. The result could be hazardous if you connect a house-fed aluminum wire to a copper wire. You may not achieve the best results if you connect a solid 14 AWG wire to a stranded 16 AWG wire.

Can You Solder Different Gauge Wires Together?

Soldering iron next to different gauge wires

It is possible to solder different gauge wires. To solder wires of different gauges, you will need to use a soldering iron that can accommodate two different sizes of wire. The smaller gauge wire will need more heat than the larger one for the solder to flow properly and create a strong joint.

When it comes to soldering different gauge wires together, there are some things you need to keep in mind. The voltage difference is the first to consider. 

The higher the voltage of a wire, the thicker and stronger it needs to be. For example, if you are soldering a 14-gauge wire together, the soldering should be stronger to handle a lot more voltage than an 18-gauge wire.

Why You Should Not Connect Different Gauge Wires

Connecting different gauge wires is a common mistake that many people can make. Here are the main reasons you shouldn’t do this:  

  • The differing levels of thickness in the wires can cause them to heat up and eventually melt.
  • The difference in insulation may cause them to ignite or even explode if they are too thin or there is insufficient insulation around them.
  • A 6 AWG wire is stiffer and heavier than a 10 AWG. Unless the wires are physically supported, the heavier wire tends to stress the lighter weight one.
  • Wire prices are based on wire sizes. If a 10 AWG wire works well in your application, then you don’t need to spend the additional money for a 6 AWG.
  • The ampacity or the amount of current a wire can carry is a key determinant when connecting different gauge wires. If your circuit requires a 6 AWG wire, a 10 AWG wire will likely cause wires to melt, which may cause a fire hazard, short circuit, or even an explosion.
  • Connecting different gauge wires could cause confusion in the future. If someone sees the 6 AWG wire, they could assume the circuit can hold a larger current.

When To Connect Different Gauge Wires

You can connect different gauge wires in certain situations, but you will need a qualified technician. You will need a fuse or circuit breaker to work as your overload protection and supply the smaller gauge wire with the correct circuit. The fuse has to be the same size as the smaller gauge wire. 

It is important to note that the bigger the wire, the lower the gauge number and vice versa. For instance, when you want to connect a 14 AWG wire to a 12 AWG wire, you will need a 15 Amp breaker or fuse.

A major factor to consider when connecting different gauge wires is the ampacity of your circuit. For example, if you are trying to pass 30 Amps through an 18 AWG wire connected to a 14 AWG wire, this could cause a problem.

Factors That Determine Wire Gauge

Several types of wire laid out in a design

The American Wire Gauge (AWG) system is a standardized way of measuring the size of electric wires. It is commonly used to determine the thickness and diameter of wires. The lower the number, the thicker and heavier the wire will be.

The AWG system starts with a range from 1 to 36. Thicker wires are assigned higher numbers, and thinner wires are assigned lower numbers, which means that when you have two different types of wires, they can be compatible with each other as long as they fall within that same range.

Three factors determine the wire gauge:

  • The physical characteristics of the material used to make the wire, e.g., its tensile strength, ductility, and hardness.
  • The thickness of insulation needed for safety and environmental reasons.
  • The ampacity of the wire (the amount of current or load the wire can carry).

Final Thoughts

If you are not a professional electrician, it is not advisable to mix gauge wires because the wire gauges have different thicknesses and capacities. When you mix them, the capacity of the wire will be less than what it should be. Working with a qualified electrical technician can save you time and money.

It is important to find someone qualified for the job. Hiring an unqualified electrician can result in faulty wiring, electrical fires, and even death. Some people think hiring an electrician is expensive, but it’s not as expensive as replacing all your wiring or getting electrocuted.

For more, check out Do Surge Protectors Work Without a Ground? | A Quick Guide.