How To Identify Neutral, Hot & Ground Wire With Multimeter?

Naturally, most people don’t think about wires until their lights go off in the middle of the night, and when that happens, your first test would be to identify which wire is faulty and which one you need to fix. But the problem is, a neutral wire isn’t like most wires, and you might need the help of a multimeter to identify it.

So how do you identify a neutral wire with a multimeter?

The first thing to do is to set your multimeter to the highest voltage on the AC range and then locate a wall outlet. With your probe, test if your outlet has electricity because without electricity, you can’t correctly identify anything. Finally, bring out all three colored wires at the back of your outlet and put your red multimeter probe against each of them. And If you don’t get a reading on one of them, that one is the neutral wire.

Steps How to identify Neutral, Hot, and Ground wire using a Multimeter

This process is pretty straightforward; all you have to do is find a power outlet and set your multimeter to the highest point on the AC range. And with the aid of your black and red probe, touch each of the wires at the back of your outlet to determine if it’s hot, neutral, or ground.

  • Step 1: Get yourself a probe and a pair of insulated gloves for your safety. Touching a wire with electricity could land you in big trouble
  • Step 2: Locate a wall outlet and bring out all three colored wires at the back of your outlet. And then set your multimeter to the highest voltage setting on the AC range.
  • Step 3: Connect your black multimeter probe to a ground wire or any grounded object such as a water pipe, faucet, fridge, or heating radiator. And if it reads on the multimeter, it is a ground wire.
  • Step 4: Then, finally, with your red probe, touch the exposed wires. If you don’t get a reading on your multimeter, your wire is neutral, and if you get a reading, the wire is hot.

This method also applies to socket-outlets of people living in the USA and Canada, the small slot is for the hot black wire, and the larger one is for the neutral black wire.

However, there are precautions that even a master electrician must adhere to before identifying any wire for safety and the smooth running of the wire test.

  • Try to keep your hands on the rubber parts of your multimeter to avoid making contact with electrically live surfaces.

  • Wear safety goggles to protect your eyes against electrical flashes, especially during electrical testing.

  • Don’t forget to put on a pair of insulated pairs to protect your hands

  • If you’re a first-timer, you should work on electrically dead systems. To avoid getting shocks and burns.

How to Differentiate a Neutral Wire from a Live Wire?

A live or hot wire can be differentiated from both the neutral wire and ground wire in several ways. Colors also play a huge role when determining a live wire, a neutral wire, and a ground wire. However, choosing the nature of a wire using its color is not an advisable method.

This is because a manufacturer can choose to use any color for any type of wire. The live wire is the one that carries the electric current from the source of power to the load while the neutral wire returns the electric current to the power source, thereby completing the loop.

Also, the live wire voltage is the same as the main supply(e.g., 220V or 230V), while the voltage of the neutral wire is 0V.

Why You Should Own a Multimeter?

There are several reasons why a multimeter can come in handy while you’re in your home. With a multimeter in your hands, you can test batteries, identify a wire, and even find a bad switch. You can also figure out if your light bulb is blown out or still works.

For any other person, this might not be a big deal, but for a DIYer, it’s a necessity and will add more firepower to your DIY arsenal. Now, let’s look at some of those little problems a multimeter can help you solve and how to go about it in your abode.

  • Test Batteries: Imagine calling your friends over for a game night, and your tv remote controller decided to fail you, and you have a box filled with old batteries, but you don’t know if they’re fried or still have juice in them. Don’t worry; your multimeter voltage modes has got you covered.

All you have to do is put your black probe on COM and your red on Volts, then set your multimeter to direct current (DC) voltage position. And if your MM has an auto-range feature, simply look for the voltage symbol (V) with a line above it indicating alternating current.

Then put on your multimeter and use its black probe to touch the negative end of the battery you’re testing. And alternately, use the red probe to touch the positive end of the battery. Afterward, you should see your multimeter display the voltage of your battery on the screen. If it’s 1.5V and above, then your battery is still good, but if it is lower, it means your battery is dying or dead.

  • Finding a Bad Switch: When the light goes off, it’s not always the bulb; it could be your switch. But you never really know until you test it out, and your multimeter can help you with that.

Unlike before, you’ll have to set your multimeter to resistance mode, but you’ll still put your black probe on COM and your red on Volts, and don’t forget to put off your light switch.

At this point, your multimeter should be displaying “OL,” which means there’s an infinite resistance on the switch circuit because your switch is off. Then for the real test, put on your switch and do the measurements again. Your screen should either show a value close to zero or still maintain the “OL” display. If it’s the former, then your switch still works; if it’s the latter, then it means it is faulty.

You can still do a lot more with your multimeter, such as reading temperatures, testing a wall switch, and testing electrical outlets.

Related Readings:

How To Test If Wire Is Live/Hot Without a Multimeter?

How To Check if Multimeter Is Working Properly? – 7 Steps

How To Check If Wire is Broken With a Multimeter? – 4 Steps

How To Measure and Identify Resistor Using Multimeter & Color Codes?

What is a Multimeter?

A multimeter is an electronic instrument used to test pieces of equipment and is mainly used to measure voltage, current, and resistance. However, that’s not all it can do; it can also be used to test continuity between electrical components and circuits.

Mind you, while a multimeter is known to act as an ammeter, ohmmeter, and voltmeter, it is worth noting that it can also be used for household purposes like battery testing, power supplies, and household wiring.

There are three types of multimeters, namely: Analog, Digital, and Fluke. Amongst all three, the digital multimeter is the most commonly used one, and while you’ll probably come across different models with prices ranging from $1000 above, simply ignore them. Those are for professionals and are designed to handle tasks far more tedious than the needs of a DIYer like yourself. Instead, you’re better off purchasing ones that cost below $10.

Here’s a short video on how to use a multimeter for beginners:


Determining the nature of a wire using a multimeter is a much safer option than using colors because, as stated before, there is no consistent color of hot, neutral, and ground wires. Multimeters, therefore, are great tools that come in handy when you want to determine the voltage, resistance, and current flowing through wires in a particular cable without having to purchase or use an ohmmeter, voltmeter, and ammeter separately, thereby reducing the cost of getting all three.

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