How to check 120 volts with a multimeter?

Do you want to ensure that all of your electrical devices in your home or office operate safely? Do you want to learn how to use a multimeter to test 120 volts? Checking the voltage on wall outlets is an important part of electrical safety, and it is simple to do in a few steps. In this article, we’ll go over how to use a multimeter to accurately measure AC power safely at 120 volts so you can tell if your wiring is working properly. So keep reading for all of the necessary tips and advice!

Difference Between 120V and 240V Outlets

When it comes to power appliances and other electronic devices in homes, there is a significant difference between outlets that use 120V power and those that use 240V power. In North America, most residential wiring utilizes 120V power, with two live wires supplying the electricity. Normal household appliances such as TVs, computers, lamps, and small kitchen appliances can draw enough current from one of the two live wires for their operation.

However, larger items such as washers/dryers, electric stoves, and air conditioners require more energy than can be supplied by a single wire – thus they need both live wires for an adequate transfer of power.

240V power divides the single-phase electricity into two separate 110V conductors that share a common neutral wire or ground. When 240V wiring is used, power is equal to voltage times current, so twice the voltage will effectively transfer twice the amount of power. This allows for more efficient use of energy and ensures that larger appliances receive enough electricity for operation.

It’s important to understand the difference between 120V and 240V outlets to ensure you are using the right type of outlet for your appliance or electronic device. In addition, it’s also important to take safety precautions when working with electrical wiring to avoid potential danger from shocks or other hazards.

How to Check 120 Volts With a Multimeter

How to Check 120 Volts With a Multimeter?

To check 120 volts with a multimeter, you must first set the meter to the “V” (volts) setting.

Step 1:

Locate the power outlet or component whose voltage you want to test. If you’re testing a device, plug it into an outlet to provide electricity.

Step 2:

Connect the test leads to the multimeter via their color-coded slots: the red lead goes into the “VA+” socket and the black lead goes into “COM,” the ground socket.

Step 3:

Turn on the multimeter and set the measurement dial to the AC voltage range you want to measure; 120 volts keep it 240 volts should be sufficient for any household need. AC voltage is represented by a waveform (~) on the dial.

Step 4:

Hold the test leads to the power outlet or component whose voltage you want to measure. The multimeter should display the reading upon contact.

Step 5:

Compare your result with 120 volts. If the reading is higher or lower, you have a faulty outlet or component. Otherwise, your voltage should be sufficient.

Step 6:

Disconnect and store the test leads properly to avoid any unnecessary damage. Always remember to turn off the multimeter before disconnecting it from its power source.

Following these steps will ensure that you can effectively and safely check 120 volts with your multimeter. Remember to keep safety first when dealing with electricity and never attempt tasks without prior knowledge of how to do them correctly!

Additional resources on using a multimeter to check 120 volts:

The first step when using a multimeter to check 120 volts is to set the meter correctly. The red test lead should be placed in the VΩmA port and the black lead inserted into the COM port.

When setting up the dial on your multimeter, make sure to select an AC voltage range of at least 220V.

Once you have configured your multimeter:

you can begin testing for 120 volts by connecting one end of the test leads to each side of the receptacle or circuit breaker that supplies power. Look at the display on your multimeter and it will indicate if there is any voltage present in that connection. If there is no voltage reading, then there may be a bad wire connection somewhere or a problem with the circuit breaker.

It is important to note that you should only use a multimeter to check 120 volts when the power source has been shut off, as it can be dangerous if done with live electricity. Also, be sure to wear safety gloves and eye protection while handling any electrical equipment.

Finally, always double-check your results and make sure all components are properly grounded before beginning any additional testing. Following these steps will ensure your safety and help you diagnose issues more quickly and accurately.

 Frequently Asked Questions:

What is the best way to check 120 volts with a multimeter?

The best way to check 120 volts with a multimeter is by setting the dial to AC voltage (VAC) and testing the two outside prongs of an outlet.

What should I do if I get a reading below 120 volts?

If you get a reading lower than 100V, then you should contact a qualified electrician as soon as possible since this could indicate that there is an issue with your electrical wiring.

Is it safe for me to test 120 volts on my own?

Yes, it is generally safe for someone who has some knowledge of electrical systems to test 120 volts using a multimeter. However, if you are not experienced in this area then it is best to get professional assistance.

How can I avoid electric shock when checking 120 volts?

It’s important to ensure that your multimeter is set correctly and that all wires are connected properly before testing for 120 volts. Additionally, make sure not to touch any exposed wiring or terminals as doing so could result in electric shock.

What should I do if my multimeter reads over 120 volts?

If your multimeter reads more than 140V then this could indicate an issue with the power supply or wiring in your home.
Again, it’s best to contact a qualified electrician to inspect your home’s wiring and make sure everything is safe. In any case, it’s important to take all the necessary safety precautions when handling electrical equipment. Always read and follow the instructions included with your multimeter before using it.


Always be careful when handling a multimeter. If you have any doubts or questions regarding the device, it’s important to contact a qualified professional for assistance. Remember to check your test leads and use insulated gloves when working with electronics. Additionally, always double-check your readings before making any changes. By taking these safety precautions and following the steps outlined above, you can safely determine if an appliance is receiving 120 volts of power with a multimeter.

Related Posts
How to use a multimeter
How to use a multimeter

Are you a DIYer who wants to learn how to use a multimeter? Are you an electrician needing to brush Read more

How to use a clamp meter to measure voltage
How To Use A Clamp Meter To Measure Voltage

Are you an electrician who needs to measure voltage or current without disconnecting a circuit? Would you like to save Read more

What is a Digital Multimeter

Are you a DIY enthusiast or an electrician looking to advance your projects? A digital multimeter is an important tool Read more

Clamp Meter VS Multimeter
Clamp Meter Vs Multimeter

Are you looking to do some electrical work around the house? It can be intimidating to tackle a big project, Read more