Compared to ungrounded outlets, grounded outlets greatly improve the safety of your home. However, one of the most common problems I see during home inspections are ungrounded outlets, especially in older homes. In this blog, you will learn the importance of grounded outlets as well as how to fix ungrounded outlets by installing GFCI’s to replace an existing ungrounded outlet.
What’s the Difference between Grounded and Ungrounded Outlets?
In order for an outlet to be grounded, a three-slotted outlet must have three wires attached to it – a hot (black), a neutral (white), and the ground (bare copper).
It is important to note that even though an outlet has three slots, it may not actually be grounded because there may not be a ground wire connected to it. In other words, a three-slotted outlet can be either grounded or ungrounded.
On the other hand, a two-slotted outlet will never be grounded. There is no way to connect a ground wire to an outlet with only two slots.
Why You Need Grounded Outlets
Grounded outlets are designed to protect people when there is faulty wiring or faulty equipment plugged in. When an outlet is grounded, it allows to breaker to trip if a ground fault (unintentional short circuit) occurs, or if faulty equipment is plugged in. When the breaker trips, it removes the shock or electrocution hazard.
When an outlet is ungrounded, it does not have the same protection. If the breaker does not trip the outlet and faulty equipment remains energized, it creates a shock or electrocution hazard to anyone who may touch it.
If you choose to fix your ungrounded outlets, you have a couple of choices.
- You can rewire your entire house to have all grounded outlets, or
- You can install GFCI-protected outlets in certain places, an option that will likely save you thousands of dollars over the cost of rewiring your house.
Installing a GFCI (ground fault circuit interrupter) provides essentially the same amount of protection that a grounded outlet would provide. It won’t cause the breaker to trip, but if there is ever a ground fault, the GFCI will trip, killing power to that outlet. This would protect someone from potentially being electrocuted.
How to Fix Ungrounded Outlets by Installing GFCI’s
*If you are unfamiliar with or do not understand basic electrical procedures, I recommend hiring a licensed electrician to do this work for you. I am not responsible for death, injuries or damage caused by using this information.
Materials needed:
- Philips screwdriver
- Flathead screwdriver
- New GFCI outlet and hardware
- Wire cutters/wire strippers
- New wall plate (may or may not come with the receptacle)
- Outlet tester (optional)
- Voltage tester (optional)
1) Turn off the power
You always want to have the power off when doing any electrical work. Go to the breaker panel and turn off the power to the room where you will be working.
If your breakers are not labeled, you may have to turn off one breaker at a time until you see that the power is off in the room where you will be working.
Before starting any electrical work, use the outlet tester or some other electrical tester to verify that there is no power to the outlet where you will be working.
2) Locate the first outlet in the chain.
(This step may require some trial and error.)
In normal electrical wiring, the power normally goes to one outlet from the breaker panel, and then from that outlet to the next outlet and from that second outlet to a third outlet, etc. (See diagram) This is called daisy chaining.
If you can locate the first outlet in the “chain” all you need to do is install a GFCI-protected outlet in place of that first outlet, and all other outlets downstream of that outlet will then be protected by that one GFCI-protected outlet.
Locating the first outlet in the “chain“ is probably the most difficult part of this process.
The first outlet in the chain is normally going to be the outlet in that room that is closest to the breaker panel. This is because when electricians wire a home, they use the shortest length of wire possible from the breaker panel to a particular room.
Knowing this, you can normally guess which outlet is the first outlet in the chain, but obviously, this must be verified.
When you find what you believe is the first outlet in the chain due to its proximity to the breaker panel, do the following.
a. If you have not already done so, shut the power off at the breaker panel.
b. Remove the cover plate from that outlet.
c. Loosen the two screws holding the outlet into the box in the wall, and pull the outlet out of the wall slightly.
d. If there is only one set of wires (a black and white), then this cannot be the first outlet in the chain. It is most likely the last outlet in the chain. The first outlet in the chain (and most other outlets in the chain) will have two sets of wires attached: the wires coming from the breaker panel, and the wires going to the next outlet in the chain.
e. If there are two sets of wires on the outlet (4 total wires), remove one of the black wires from the outlet either by loosening the screw and taking the wire off the screw or using wire cutters to cut it loose.
f. Turn the power back on at the breaker panel. NOTE: The circuit will now be energized, so DO NOT touch the outlet or wires that you have just removed.
g. Use your outlet tester to see if all other outlets in the room are now dead. If they do not have power, then you have correctly identified the first outlet in the chain. If some outlets are dead and some are not, then there are other possibilities. Either you did not identify the first outlet in the chain, or more than one circuit supplies that room. Assuming the room is on one circuit, you will need to reattach the wires to the outlet from step “e” and try again.
I am not going to get into all the other possibilities such as the room being on more than one circuit, other than to say that you in this case you would have to identify two outlets that are first in the chain and then replace both of those with GFCI outlets.
3) Install a GFCI outlet on the first outlet in the chain
Now that you have located the first outlet in the chain, all you have to do is replace this outlet with a GFCI protected outlet.
a. The first thing you need to do is to determine which of the two black wires is the wire coming from the panel. This is pretty simple since you have one disconnected from the outlet already.
With the power on (make sure not to touch anything that could be energized), use your voltage tester to see if the disconnected wire is hot or if the wire connected to the outlet is hot. Whichever of these two wires is hot will be the wire coming from the panel. You will need this information to properly wire the GFCI-protected outlet.
b. Turn the power back off at the breaker panel
c. Use an outlet tester again to make sure the power is off.
d. Mark the wire that you identified as coming from the panel. You can do this by putting a small piece of tape on that wire or through some other means.
e. If you previously had to cut the wire to remove the old outlet, use your wire strippers to remove the insulation from the ends of the wires so you can attach the GFCI outlet
f. Get your new GFCI outlet and look at the back to **identify the ‘Load’ and ‘Line’ screws.
**NOTE- You will see a “Load” and “Line” side on the back of the GFCI outlet. “Line” will be connected to the power supply. “Load” will be connected to the downstream receptacle.
You will be attaching the wires to the corresponding screws on your new GFCI receptacle. It is important that the wires are in the right place. These wires need to be on the side that says “Line”.
g. Attach the wires to the GFCI receptacle.
The black (hot) wire will be attached to the gold screw, the white (neutral) wire will be connected to the silver screw, and the green or bare copper (ground) wire will be attached to the single green screw located at the bottom of the receptacle.
When attaching the wires, you want the loops going in the direction that you tighten the screw (clockwise).
Once the wires are on the correct screws, tighten the screws with your Phillips head. The screws should be tight but you don’t want to overtighten them because it could crack the receptacle.
Since you want this GFCI to protect the next receptacle in line, you will hook the wires going to that receptacle on the “Load” side.
h. Secure the receptacle in the box.
Once the wires are properly attached, push the receptacle back into the box so you can screw it into place. You will likely have to adjust the wires to get the outlet completely into the box.
Screw the receptacle into the box using a screwdriver. There should be two screws for this, one at the top and one at the bottom.
I. Place the new wall plate over the receptacle.
With your screwdriver, screw the wall plate into place.
j. Turn the power back on.
Go back to your breaker box and turn the power back on.
k. Test the GFCI receptacle
First, push the reset button. Using your outlet tester, ensure that it as well as the outlets following it in the chain have power.
Then push the test button on the receptacle and ensure that it trips. Now use your outlet tester to make sure that it and the rest of the outlets in the chain have no power.
Reset the receptacle by pressing the reset button.
Now you know how to fix ungrounded outlets by installing GFCI outlets, which could save you a lot of money compared to rewiring your entire home.
I hope this blog was helpful. If you’d like to see step-by-step how it was done, I have a video where I show how to fix ungrounded outlets by installing GFCI outlets.
© 2022 Mike Morgan
This article was written by Mike Morgan, the owner of Morgan Inspection Services. Morgan Inspection Services has been providing home, septic and well inspection services throughout the central Texas area since 2002. He can be reached at 325-998-4663 or at mike@morganinspectionservices.com. No article, or portion thereof, may be reproduced or copied without prior written consent of Mike Morgan.
