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How to Check 240 Voltage With a Multimeter in 3 Steps

Written by Edwin Jones / Fact checked by Andrew Wright

how to check 240 voltage with a multimeter

Voltage checking of an outlet or a circuit is required when troubleshooting your home electrical connections. If you know how to check 240 voltage with a multimeter, you will know if there are some irregularities in the power supply.

Simultaneously, this will give you knowledge regarding which devices are suitable for that circuit.

This article will show you how to check your outlet’s voltage and amp draws using a multimeter. It may help a DIYer who wants to learn more about electricity as well as multimeter usage.

Tools Needed


1. Multimeter

When checking the voltage of an outlet or any circuit line, you will need a multimeter. You can use any multimeter—digital or analog. Almost all types of multimeters can measure current, resistance, and voltages in both AC and DC connections.

Additionally, depending on the model of your multimeter, it may have different functions. Some multimeters have a selector dial, a clamp, and some have auto-ranging features.

Moreover, there should be two probes (red and black) for various measuring operations.

2. Insulated gloves and safety goggles

Since you will work with dangerous voltage, safety equipment is beneficial, especially if you are a beginner in electricals. Having gloves can prevent electrocution when you accidentally touch any bare parts, such as the prongs of the probe.

How to Check Voltage with Multimeter for Your Outlet?


Step 1. Identify the Outlet

A standard 120 volts outlet in your house has three openings, one hot, one neutral, and one ground. On the other hand, a 240 volts outlet has three openings for two 120 volts hot wires and one neutral wire.

However, newer electrical outlets have four openings: two hot wires, one neutral wire, and one ground wire.

Step 2. Set Your Multimeter

If you use a digital multimeter with a selector dial, make sure to set it to read AC with a range of 240 volts since we will test a 240v outlet.

Furthermore, you must also plug the red probe into the VΩmA inlet and the black probe into the common inlet. This is also the right time to wear your goggles and gloves to add safety to your operations.

Step 3. Testing 240 Volts With Multimeter

To test your 220V outlet, you must place the two probes into the two vertical openings. There should be a reading of 220 to 240 volts.

You can also place the red probe into each one of the vertical openings and the black probe into the circular opening or the ground. The reading should be 120 volts.

Also, it is the same for four-prong outlets. The two vertical lines should read 220 to 240 volts.

You can refer to this video by D3RPZILLA to visualize how to test 240 volts outlets properly.

How to Measure Amps on 240v Circuit With Multimeter?

Knowing how to measure the amps of a 240-volt circuit will give you knowledge of how many appliances you can use on it.

The easiest way to get the amperage of a particular 240 volts circuit is by using a clamp-type multimeter. This multimeter is handy, especially if you have more than one outlet in one circuit.

  • You only need to set the selector dial into the amp reading and find the circuit of your 240 volts outlet in your breaker box.
  • However, you may need an extra tool such as a screwdriver to disassemble the cover of your panel breaker. Remember to take extra care as you are working with live connections.
  • After that, you can clamp your multimeter into the hot wires of your specific circuit that you want to test. You can now plug in your appliances to the circuit and turn it on to the maximum settings.

Your multimeter reading will tell how many amps are going through your circuit.

If the reading is more than 80% of the amp rating of your circuit breaker, there is a high possibility that it may trip.

On the other hand, if the reading is only half of the amp rating of the circuit breaker, you can add more appliances to that particular circuit.

How to Get 240 Volts?

A 240 volts supply is needed for high-powered appliances such as dryers and air conditioners. The best way to get 240 volts is to install a double-pole circuit breaker.

Though it seems to be a difficult job, the truth is the opposite once you know how to do it properly.

However, you may need to consider a few things in your circuit installation. First is the amperage ratings of your circuit breaker.

Second is the wire size and the number of wires for your circuit. Since installing a circuit with a ground connection is much safer today, you may consider using a four-wire setup with the size rated for your circuit.

Another thing to consider is the type of outlet you need in your installation. It is good to check if your outlet’s amp and volt ratings fit perfectly with the specific appliances or devices you want to use in your new circuit.


Knowing how to check 240 voltage with a multimeter will help you assess device and outlet rating compatibility. Knowing the amp draw by using a multimeter will also give you an idea of whether the circuit breaker has a risk of tripping or enough capacity to protect appliances.

Now that you’ve read this article, you can use the knowledge here in your daily life. Is there something you want to know about this topic? You can write it in the comment section below.

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