Which Wire is Hot When Both are the Same Color?

Working with live wires is both a sensitive and risky job and any electrician would tell you how important it is to know how to differentiate between hot wires and neutral wires. You do not want to mix the two up or it could lead to all kinds of problems, the most common one being short circuits. While wires are typically installed in a color-coded fashion for easy identification, sometimes that is not the case. This can be because of a bad decision when installing wiring in your home or for an appliance where the manufacturer chose to use the same wire color.

Regardless of the reason, you need to know what methods you can use to identify a hot wire when both the live and neutral wires are the same color. In this article, we will be teaching you exactly how you can do that so keep reading.

a rolled wire display at the hardware store

When dealing with electrical wires of the same color, the best option to determine which one is the hot wire, and which one is the neutral wire is to use a good multimeter. Connect it to the wiring according to the manufacturer’s instructions and the wire with voltage in it will be the hot wire.

Understanding the Difference Between Hot Wires and Neutral Wires

A simple word analysis would tell you that a hot wire is one that works at a higher-than-normal temperature. When not active, all wires are cold wires until you run electricity through them. Conducting electricity leads to heat generation and the wire that has electricity running through it becomes hot. That is why a live wire is also called a hot wire. (1)

different types of wire displayed

In a typical 1-phase system, you will have two wires running through the system, one of them carrying the electricity. This is the wire that will connect your switch to your fixtures like a lightbulb, a fan, or other electrical appliances. There are two scenarios that you can typically see when dealing with wires that are colored. They can either be red and black or black and white wire. In the first instance, the hot wire is usually the red one, whereas, in the second scenario, it is typically a black hot wire with the white wire being neutral.

However, if both have the same wire color then you can find it quite confusing to determine which electrical wire is the hot one and which wire is the natural one. Thankfully, there are methods that you can use to easily identify wires correctly, so you do not connect any of them to your sockets and appliances incorrectly.

Figuring out which Wire is Hot when Both are the Same Color

You can test whether an electrical wire is a live or neutral wire color using several different methods. However, most of the methods available come with some sort of safety recommendations. That means an amateur should not be using them as it could lead to a short circuit or in worst cases, the death of the person interacting with the wires as high voltage is quite deadly.

Therefore, we will go into detail about the only process that is safe to use and widely accepted for its very nature.

multimeter, wires and other hardware tools

The method we are referring to is the use of a multimeter. Knowing how to use one can prove to be extremely useful in a wide range of scenarios. In this case, it can easily identify which is which by conducting the electricity running through its probes.

Make sure you know how a multimeter works before you decide to use it for testing hot and natural wires.

Now that you have your hands on a working multimeter, you will need to follow these steps to identify a hot wire and a neutral wire.

  1. Set your multimeter to AC voltage mode which will typically be denoted by HVAC, VAC, or 200v. This can vary depending on the country you are in and the brand you are using. Be sure to get a good quality digital meter so you do not short it or cause any other damage accidentally.
  2. Touch the red probe on the multimeter to one of the wires and then touch the black wire probe on the housing of the socket which is typically made of metal. The housing will serve as the grounding station meaning once you connect to the live wire, the current will be delivered into the ground and not cause damage to the multimeter or yourself.
  3. Look at the readings that show up on your multimeter now. If you are seeing a reading of 0 or a value quite close to it, then the wire you are touching with your red probe is the neutral wire color. However, if the value on your multimeter is around 100-120 volts, then you are touching the live wire with your hands. This value can also be between 200 and 240 depending on the voltage regulation in your country. (2)
  4. Double-check the wires to be sure which is which and then mark the live one by adding a small piece of electrical tape to it. You may also use some other methods as well but make sure none of them involves damaging the wire in any way.

Wrapping Up

Electricity is a dangerous thing, and you will never get a second chance to fix your mistakes if you mess things up. That is why it is extremely important to know which wires are live and which are neutral. A wrong connection can lead to all sorts of problems that you do not want to see. Follow our guide carefully and make sure to follow all safety recommendations.

Take a look at some of our related articles below.

(1) Conducting electricity – https://www.scientificamerican.com/article/
(2) voltage regulation – https://www.sciencedirect.com/topics/engineering/

About Sam Orlovsky

b1d87d2ee85af3e51479df87928bdc88?s=90&d=mm&r=gI realized early on carpentry was a huge passion for me and I’ve stayed in the industry for over 20 years now. This gives me a unique ability to really be able to tell you what the best tools and recommendations are. I’m not only a carpenter but I also like machinery and anything to do with electrics. One of my career paths starting off was as an apprentice electrician so I also have a lot of experience with electrical products and anything related.