This post has affiliate/referral links. Learn more.
How to tell if an outlet is grounded or not in your home is a common question for electrical safety.
First, what is a grounded wire system? On an electrical outlet, see that there’s a 3rd hole below the pair that looks like a half-circle. This 3rd hole is used for the grounded outlet wire system.
However, use a multimeter if your outlet has 2 prongs. Read on for the step-by-step guide on how to tell if an outlet is grounded.
The electric wire system in your house carries electricity in two forms, positive charge and negative charge.
The positive charge is the neutral current, and the negative one is the hot current. When the electric currents pass, it needs to discharge the negative energy.
So, it tends to go the shortest way, and the electricity runs on the outside of the wiring system or in the pipe.
This causes electric shocks, and it leads to the creation of sparks.
The surges will harm your electronic devices, or even worse, they can catch fire and can lead to severe accidents.
To avoid this problem, the electric wires need to be grounded. The two holes in an outlet carry hot and neutral charges.
And the 3rd hole carries a different pathway. It consists of bare copper wire, which is connected to a grounded rod.
The rod is buried deep in the ground near your home. So, the hot current can easily pass to the ground without harming your home appliances.
This helps prevent typical electrical accidents in the home.
So, it is essential to know if your house’s wiring system is grounded or not. Most of the homes built in the last few decades have a grounded cable system.
But due to aged or loose cable connections, the grounded system may not work. So, you should check the wiring system.
Method 1: How to Tell If an Outlet is Grounded for 3-Prong Outlets
Step 1: Check with local eletrical safety codes
If you are planning to make changes to the electrical work, be sure you’re up to building code for residential projects.
You may have to schedule a service inspection and get a permit.
Step 2: Use a 3-Prong GFCI Outlet Tester
This 3-prong testing tool helps you identify grounded outlets.
The outlet tester has an easy light indication to help you identify the wiring of standard 3-wire outlets, as well as test GFCI outlets.
GFCI outlets are usually required by the electrical code for outlets that are located near water fixtures.
Step 3: Plug it into the outlet
To tell if an outlet is grounded, plug the outlet tester into the 3-prong outlet.
Test the outlet receptacles one at a time. You may have to turn the circuit breaker on and off while you work for any circuits that may have tripped.
With a pencil and sticker, mark the results of the test.
Method 2: Using A Multimeter to Tell If An Electrical Box is Grounded
If you have a metal box with no ground wire, you can test it with a multimeter to see if it’s grounded.
The multimeter comes with a red probe and a black probe.
Connect the red probe on the hot wire coming into the electrical box.
Connect the black probe to the neutral wire.
The multimeter will show your voltage. This shows your wiring is live.
Now, connect the black probe to the metal box. If the multimeter shows the voltage, it means the electrical box is grounded.
Method 3: Using A Multimeter to Tell If A 2-Prong Outlet is Grounded
Step 1: Gather the tools
The first thing you need to do is gather the tool essential for testing. You will need a digital multimeter for this.
You can find a multimeter on Amazon or at a hardware shop near you.
Step 2: Locate the outlet
Once you have the multimeter, locate the power outlet that you want to test.
Take safety measures to prevent electric shocks.
You may have to unscrew the faceplate to reveal the metal box.
Step 3: Connect the multimeter
After locating the outlet, you need to connect the multimeter to the outlet.
Connect one probe to the hot receptacle slot.
Connect the other probe onto the neutral slot.
Step 4: Check if the outlet is receiving power
If the reading comes near 120 volts, or your local voltage, the outlet is receiving power.
Step 5: Check if the outlet is grounded
If you find that the outlet is receiving power, then move the probe from the neutral wire to the plate screw or metal box.
Now, you will have one probe on the hot receptacle. And one probe on the plate screw or the metal box.
Check the voltage. It should read 120V or your local voltage.
If the reading is not the same, the outlet is not grounded correctly.
This is a straightforward test you can run to check if your house’s outlet electrical wiring system is grounded or not. And will only take moments to find out.
Are All Three-Prong Outlets Grounded?
The houses that are built in the last few decades contain new electric outlets, which are three-prong outlets.
This type of outlet is an indicator of a grounded wiring system. The third hole in the outlet is the path of a grounded system.
However, that does not mean all three-prong outlets are not grounded properly. The grounded system should be there, but due to loose wires or aged connections, the system may not be working.
So it is essential to check all the three-prong outlets to find out. Plug in a 3-prong outlet tester to find out if it is grounded.
The old two-prong outlets may also contain the modern system with a grounding metal box. These should also be checked as to whether the outlet is grounded.
If the outlet has been renovated in recent years, then there is a chance of having a grounded system in the outlet.
So, you need to check with a multimeter to find out if the outlet is grounded or not.
Are Ungrounded Outlets Safe?
Having grounded outlets are essential and can prevent accidents around the house. But if you have an ungrounded outlet, is it safe?
The outlet is vulnerable to electrical accidents if it is not grounded. Ungrounded outlets cannot carry the hot current to the ground.
That’s why the outlet becomes prone to electric shock. If any electrical home appliances are connected to it, a short circuit may occur.
As a result, the machine will be damaged. And the circuit may spark a fire in the house, which will be dangerous.
Your life and property will be at significant risk if the outlet stays ungrounded.
How Much Does It Cost to Fix Ungrounded Outlets?
For a safe home, grounded outlets are essential. It prevents accidents and property risks.
If your house still has ungrounded outlets, you need to replace them as soon as possible. You need to contact a licensed electrician to do the work.
A new outlet will cost around $80 to as much as $500. The cost of receptacles depends on the type you need, and the price is approximately $4 to $50.
An expert electrician will cost around $50 to $100. With all the other costs, an average grounded outlet installation will cost from $200 to $300.
Overall it is not that expensive to replace the outlets. So, upgrade the ungrounded outlets of your home as soon as possible.
Test all the outlets of your house and figure out if the system is grounded or not. If not, change the wiring system as soon as possible to prevent the risk of accidents.